Showing posts with label Engine Stalling. Show all posts
Showing posts with label Engine Stalling. Show all posts

Saturday, April 10, 2010

Purring Like A Kitten!

I got the Volvo back from the shop earlier this week and it's purring like a kitten! Erratic idle - gone! Engine Stalling - gone! Running rich - not anymore! I took it to a shop in town called British Steel Restorations. Rick Rogers, the proprietor, and a former helicopter mechanic specializes in the restoration of classic British automobiles. I figured, if he can fix helicopters, he'll surely be able to fix the Volvo! I've known Rick for a couple of months prior to taking the Volvo in for work ... having sought him out, and set up a couple of meet-and-greets to tour his facility, evaluate his work, and more importantly, to lure him to the dark side by coercing him to temporarily abondon his staple of fine British classics to work on my Volvo as it surely has enough British components in it to qualify. It does - Smith gauges, Lucas electrical components, Laycock De Normanville overdrive is similar to the TR6 or 7 models, etc.

Are there any other places in town to take the Volvo to? Sure, but I'm extremely particular when it comes to people working on my car as I don't want it to be molested by any regular mechanic with a socket wrench. It has to be someone who is also a collector, who specializes in vintage vehicles, who will handle my Volvo like they would a radioactive fuel rod. Hence, the many months of research and interviews for just the "right" mechanic. There are Volvo dealerships that I could have taken it to, but I doubt that they still employ the guys that were around when the 1800s were still on the market. Plus, they usually don't let you "hang-out" and watch while they work on your car - where's the fun in that? Anyone who no speaka ingrish - is automatically disqualified. Shops that won't allow me to bring in my own parts were also disqualified (it's a sign that they'll mark-up the parts that they'll undoubtedly need to source from a third-party). Mechanics with a low teeth-to-tattoo ratio were also disqualified (different though if you need radiator work done - you'd want the biker guys with the low teeth-to-tattoo ratio, as they really know their shit!).

The main reason for the visit was to have the Volvo complete its tune-up with an oil change, valve adjustment, oil filter replacement, and have Rick verify with his instuments all my prior adjustments to the idle richness, timing, idle & throttle settings. The stuff that I messed with were all pretty close, but we (by "we", I mean "Rick") did it again with instruments this time to get them within factory specs. Turns out, all the valves needed adjusting - which is most likely the cause of the erratic idling and engine stalling. With everything dialed in to specs, the engine is running much quieter and better than its ever been since I've had the car!

Arrival at British Steel Restorations: 1971 Volvo 1800E Chromed Valve Cover & Oil Cap: Volvo 1800 Chromed Valve Cover & Oil Filler Cap

Pictured above, on the right, is the chromed valve cover & oil filler cap that I stole off eBay about 8 months ago. I've been itching to get it on the engine ever since, and now the opportunity has presented itself with the removal of the old valve cover for the valve adjustments. Pictured below are the before-and-after photos of the engine bay with the old vs. chromed valve cover in place. Take a closer look at the chromed valve cover and you'll see the valve cover hold-down kit that I got from IPD. These valve covers are prone to distortion from overtightening the mounting screws. This leads to improper sealing and oil leaks. The hold-down kit spreads the clamping force over a larger area, allowing the gasket to better seal against the cylinder head.

Before: B20 Valve Cover - Before After: B20 Valve Cover - After

Another thing that I had done while the car was in the shop was the replacement of the rubber steering coupler. Mine had a few tears in it. It is a part that is often overlooked when purchasing a vintage vehicle, but is crucial as you will lose the ability to steer if it comes off! I also instructed Rick to take a good look at the entire vehicle to identify anything that might affect drivability or safety that needed replacing. He found one - the driver-side tie rod was "barely" hanging on and it was promptly replaced with a brand new one from IPD. Other than that, Rick's report was very encouraging - everything under the car looked solid, no rust on the floor pans or cross members. The car is mechanically and structurally sound. The rest is just appearance items or aged parts that currently do not affect the drivability or safety of the vehicle and can be swapped out at my leisure.

I also had Rick perform a compression check on the engine just for the heck of it, and the results for each of the 4 cylinders were well within the range for an engine of its age, and the variances across cylinders were within norm (I don't have the test result on hand right now, and it's all greek to me anyway - all I know is he says it's all good, so I'm driving it across the Atlantic). At one point Rick even had a scope down the fuel tank and was happy to report that it looked like it was in great shape and the outbound fuel was clean. Good news for me, as it's one less thing to restore!

Before: Volvo 1800E Engine Bay with Old Valve Cover After: Volvo 1800E Engine Bay with Chromed Valve Cover

ZDDP - I read somewhere that it's good for flat tappet engines (here and here, I think!). Unfortunately modern engine oils no longer have it, but here's an additive that I bought from iRollMotors.com called ZDDPlus (picture below, left) that can be added to the engine at each oil change. I also found out later that Valvoline VR1 20W-50 motor oil still has the appropriate levels of the stuff, so that'll be the oil I'll be using in the future with no need to spend the extra $10 for the ZDDPlus additive.

ZDDP Additive: ZDDP Additive Instrument Cluster: Volvo 1800E Instrument Cluster

Ever since I've had the Volvo, the following instruments on the dash were not working: Oil temperature gauge, fuel gauge, turn signal indicators on the dash would only flash once, and the emergency brake warning light on the dash would stay lit all the time the car was running. The gauges were in working condition, just the wiring (or in the case of the oil temperature gauge, the sensor) needed some attention. Well ... the oil temperature gauge was a simple fix. Installing a new oil temperature sender during the oil change solved that problem. As for everything else ... heck of a lot easier as it turns out! The brake warning light first of all has a dual purpose - It lights up when the the emergency brake is engaged when the engine is running, and it lights up when there is unequal pressure in the brakes as sensed by a switch in the engine bay. Neither of which applies in my case as I'm aware that the previous owner had some electrical work done by his mechanic which resulted in 2 things happening - the warning light being lit all the time, and the fuel gauge stopped working. This is where the giant colored wiring diagram I purchased a couple weeks ago proved useful. It seems that the previous mechanic got creative with one particular wire in the dash, and upon removing the "stray wire", everything on the dash started working! I mean everything ... the fuel gauge works perfectly now and it is accurate (we tested). The brake warning light works like it should. Even the turn signal indicators on the dash started behaving - they flash continuously until disengaged. Bonus! I'm crossing off a bunch of stuff from my to-do list with one pull of a wire!

Sunday, March 7, 2010

Got It ... Kinda!

I managed to get the engine running way past the 7 minute mark after making adjustments to the air/fuel mixture. It's not pretty ... the engine revs higher than I'd like it to at idle, but that should keep it from stalling when I drive it to the shop. The first thing I did after the static timing, was to invest in a fuel pressure gauge. The fuel pressure was indeed at the recommended 30 psi. Next, I adjusted the throttle butterfly located in the mouth of the intake manifold. This was done via the throttle adjustment screw pictured below. The various instructions call for a 1/4 or 1/2 turn of this screw from the point of contact with the throttle valve spindle. I did mine at 1/2 turn. By the way, I had to use a dental mirror to get a visual of when the screw was making contact with the throttle valve spindle. The purpose is for this screw to hold the throttle slightly open as it should never be completely closed. I found that mine was originally opened more than it needed to be as if someone used this to adjust the idle instead of the idle adjustment screw located below the mouth of the intake manifold. The second photo below shows the throttle adjustment screw after the adjustments have been made. Having messed with throttle butterfly, the next procedure was to reset the position of the throttle switch to accomodate the new setting.

Throttle Adjustment Screw: Throttle Adjustment Screw Close-Up: Throttle Adjustment Screw

Next, was the idle adjustment screw - I removed it completely from the manifold and cleaned it up with electronic contact spray. Here's how it looks like pictured below. I also sprayed a whole bunch of electronic contact cleaner down the hole indicated by the red arrow in the next photo below. This is where air for idle gets through and the volume of air is restricted by the idle adjustment screw. Needless to say, a tsunami of black stuff came out of that hole that could be restricting air flow.

Idle Adjustment Screw: Idle Adjustment Screw Throttle Butterfly: Throttle Butterfly

I also figured out what that knob was on the side of the ECU. I originally thought it was some sort of fuse (red arrow in the photo below), but it's the idle enrichment knob. It controls the richness or leaness of the mixture, but only at idle. Clockwise is richer, counter clockwise is leaner. It increments in "clicks". Once all that stuff above was dialed-in, tuning the idle air/fuel mixture was a matter of adjusting the idle screw and messing with the idle enrichment knob on the ECU.

Idle Enrichment Knob on ECUSince I don't own any instruments like a CO meter, or revolution counter, adjustment of the idle and air/fuel mixture was done "by ear" and the use of a caged canary next to the exhaust pipe. Alright ... it was way less low-tech than that! Using my own body as an indicator, the more nauseous I got and the more burning and watering of the eyes from the exhaust fumes - the richer the mixture. So I adjusted the idle screw and leaned out the mixture via the idle enrichment knob on the ECU accordingly until the feeling of wanting to throw up went away.

It was tricky dialing in the right combination of idle air flow and mixture richness/leaness to arrive at a compromise that'll work for now. All this has to be done with the engined warmed-up by the way. Lot's of trial-and-error and measuring engine "run time" with a stop watch to see if it's running past the 7 minute mark. My neighbors hate me now I'm sure of it, and I think I might have also single-handedly depreciated the real estate values in my neighborhood while prospects were attending open houses this weekend.

Before: After:

In the midst of all the adjustments, I also managed to sneak in some "rotary tool" time and went to town on that thing that secures the throttle cable to the manifold. I don't know what it's called, but the before-and-after pictures are above. In the end, I took the Volvo out for a spin around the neighborhood for various lengths of time, stopping at every intersection to see if the idle drops and the engine stalls. Aside from sounding like I have a V8 under the hood, there were no problems at all during my test drive. It is only after each test drive, when I'm pulling into the drive way, the idle drops and I have to tap the gas pedal to keep it from stalling! I drove it for 20 minutes one time, and it almost stalls 10 feet from the driveway. Drove it for more than 30 minutes another time (all the while stopping-and-going to try to get it to stall - it didn't), and it does the same thing 10 feet from the driveway as I was returning from the test drive. The street is flat too, so I know it's not the incline in my driveway that's causing stuff to shake up in the gas tank and possibly leading to fuel restriction. Can you believe this?!!! It's like the Volvo is trying to tell me that it doesn't want to be in the garage ... it want's to be DRIVEN! Well then ... I hope it won't embarass me on the drive to my mechanic's shop.

Saturday, March 6, 2010

Static Timing a B18/B20 Engine

As mentioned in last week's post, the goal this weekend is to dial in the timing one notch better by performing static timing as outlined in this article on the Swedish Embassy website. Once this prerequisite procedure is done, my hope is to be able to mess with some variables that affect the air/fuel mixture to get the engine to stop stalling at 7 minutes so that I may drive it to the shop to have them fine tune everything. It took me awhile to get comfortable with attempting this procedure as I was getting confused comparing the Swedish Embassy article vs. the procedure outlined in my Owners Workshop Manual. It was really the instructions in my manual that was throwing me off. In particular, their scripture read (not verbatim, as I don't have it with me as I write this) "... turn the engine until the timing mark lines up with the "0" scale on the crank pulley ... back it off until the timing mark is opposite the 10 degree scale." The word "opposite" was throwing me off - I kept thinking 180 degrees from the 10 degree scale ... which is opposite right?!! No ... they should have been consistent with their verbiage and used "lines up" or "adjacent" instead!

Anyway, the main reason for this post is so that I could post some photos as a visual reference for myself in case I wake-up from a coma with minimal recollection and I have to do this again in the future. Note to self: this pictorial guide is to supplement the static timing instructions in the Swedish Embassy article ... Why? Because I'm a moron!

First photo below shows the 10 degree timing mark on the rim of the crank pulley lined-up with the pointer on the timing cover of the engine - this is 10 degrees BTDC (TDC is at "0"). The pointer is more like a fin (red arrow in photo). Timing marks are the numbers on the rim of the crank pulley (20 ... 10 ... 0 ... 10). It took a while to find the timing marks on the crank pulley the first time around as they were all covered up in grease. Rotation of engine is clockwise when looked at from the front. Second photo shows both valves for cylinder no. 1 up and closed at ignition point (TDC) as seen through removed oil filler cap. Top of cylinder should also be visible through spark plug hole no. 1 (that's the first one from the front of the engine).

Timing Marks on Engine: Timing Marks on Engine Valves For No. 1 Cylinder: Valves For No. 1 Cylinder

Third photo below shows orientation of distributor rotor at TDC. Rotor should be pointing to cylinder no. 1. Last photo is of spark plug no. 1 grounded to the valve cover. In summary, it all went well. I static timed it to 10 degrees BTDC, and the engine started right up. Now I can make adjustments to the throttle valve, throttle switch, and idle to see if I can get to the bottom of this stalling problem.

Distributor Rotor Orientation: Distributor Rotor Pointing to Cylinder 1 Spark Plug on Valve Cover: Spark Plug on Valve Cover

Sunday, February 28, 2010

A New Clue!

I've been making observations and taking notes since performing the "rough" timing yesterday and here's what found: The engine idles at 1,500 rpm from a cold start. That's 1,500 from the car's tachometer ... which could be a bit off. Idle doesn't sound blaring loud though, rather a pleasing deep old Volvo like rumble ... or old school bus like! Anyways, idle drops to 1,000 rpm at around the 6 minute mark presumably from the engine warming up and the Auxilary Air Valve (AAV) closing down and restricting air to bring the idle down (as it should). At around 7 minutes, the idle starts to stutter and the engine soon stalls.

First off, 6 minutes before the engine warms up and idle drops seems a tad long I think ... but who knows, maybe that's normal? Second observation is at the time the idle starts to drop, the fumes from the tail pipe begin to smell like gasoline ... that and my eyes start to water. This has been pretty consistent since the first day the car started acting up. Me thinks, during a cold start with the engine still cold and the AAV open, there's plenty of air to burn off the fuel. As the engine warms-up and the AAV closes, less air gets through leading to incomplete combustion of fuel. Run the engine long enough (7 minute mark) and it soon stalls from air starvation compared to the amount of fuel being served, and finally there's enough fuel left over to flood the engine to prevent a subsequent warm or hot start until the excess fuel evaporates.

Well ... I did some reading, and learned a new word: "running rich" - when there's a high fuel-to-air ratio in the chambers ... exactly what I'm experiencing! And I though it meant hanging out with the golfers at the country club in the good side of town ... no that's "running with the rich" ... nevermind. Here's another tell-tale sign of running with a rich mixture: black sooty fouled plugs (pictured below). These are brand new spark plugs by the way!

Fouled Spark Plug: Fouled Spark Plug Crankcase Breather Hose: Crankcase Breather Hose

Now, armed with this new clue and a set of quantitative base-line data to compare against (specifically the elapsed time before things start to go south), I think my next move ought to be resetting the timing followed by checking the fuel pressure. Even though the "rough" timing I did sounds good to me (then again, any signs of life from this Volvo excites me), I think proper static timing is called for this time as incorrect ignition timing could also lead to rich running conditions from what I read. Correct fuel pressure is also critical as higher than normal fuel pressure also leads to running rich. I'll take on these two tasks next weekend as I need to consult my horoscope and purchase a fuel pressure gauge.

While messing around with the crankcase hoses checking for vacuum leaks, I noticed that the hose from the oil filler cap to the intake manifold had some mayonnaise like residue in it (pictured above). Not sure if this is normal. What is this stuff ... engine pus? In any case, I replaced the crankcase hoses with fresh ones. Some of the crankcase hoses also didn't have hose clamps on the ends and stock photos of the hoses didn't show any on them either, but I clamped all of them up anyway just to be rid of any potential vacuum leaks that might be contributing to the problem.

Crankcase Hose Nipple - Before: Crankcase Hose Nipple - Before Crankcase Hose Nipple - After: Crankcase Hose Nipple - After

The crankcase hose from the oil filler cap to the manifold attaches to a nipple which I also removed and cleaned as pictured ablove. I used a port brush for a hummingbird feeder to get the insides real good, and flushed out lots of black carbon deposits, and finally finished it off with some light sanding with the rotary tool to get rid of years of surface oxidation. In summary, none of the changes I did today made any difference to the warm engine stalling problem. I'm still checking things off my list, but I have hopes for next week as I attempt to dial in the timing a few notches better and check the fuel pressure.

Oh ... I told myself that I'm not going to be one of those people who name their cars, but after what I had to go through this past few weekends, I've changed my mind and am naming it "Legion" ... for the problems are many.

Saturday, February 27, 2010

PerTronix Ignitor Points-to-Electronic Ignition Conversion - Part 2

I was all ready to perfrom static timing on the engine this morning per the instructions on the "Swedish Enbassy" website when on a whim, I decided to turn the distributor clockwise about 5 degrees just to see what happens. Well ... I lucked-out! I had 50/50 odds of getting it back to its original timing prior to the PerTronix install by turning the distributor clockwise or counter-clockwise. The Volvo roared back to life sounding livelier and "younger" than it ever did as opposed to "tired & grumpy old Volvo." Well, that excitement lasted for several minutes until the engine warmed-up and it was back to a degrading idle and eventually stalling. The good news is, the PerTronix seems to be a promising upgrade ... all I need to do now is solve the warm engine stalling problem.

Having ruled out points as the possible culprit by replacing them with an electronic ignition module, it's time to look elsewhere for a fix. Let's see, so far the following checks have been conducted:

  • Replaced ignition coil
  • Replaced ignition wires
  • Replaced spark plugs
  • Replaced coolant/engine temperature sensor
  • Replaced engine thermostat
  • Cleaned all wiring terminals + grounds
  • Checked cold start valve - no leaks
  • MAPs sensor OK - unhooked the hose to the manifold and sucked on it. Tounge got stuck, so no leaks + pressure held. Resistance checks on terminals also OK.
  • Auxilary Air Valve (AAV) OK - Crimping the top hose dropped the idle when running engine cold. No effect on idle when running engine warm.
  • Air filter OK
  • Replaced points with PerTronix

Next on my list was to check for vacuum leaks and verify that the wiring harness to the Electronic Control Unit (ECU) was ok. While performing a visual check for any possible source of vacuum leaks, I did find a couple of tiny holes in the air intake hose pictured below. Since this hose is north of the intake manifold I don't think it has any effect on the vaccum. I sealed up the holes anyway with a few drops of Gorrilla Glue just for good measure and to prevent unfiltered air from entering the system.

Air Intake Hose: Volvo 1800E Air Intake Hose Holes in Air Intake Hose: Holes in Air Intake Hose

Now that the engine was equipped with a brand new coolant/engine temperature sensor, I wanted to verify that the wiring itself was in good shape, and thus not sending mixed signals to the ECU. I proceeded then to disconnect the Fuel Injection wiring harness from the ECU to perform the electrical checks outlined in this document I found in the Tech Archive of the VClassics Interactive website.

Couple of things I learned from this procedure: Plastic cover for the ECU slides off - do not pry it off like you would a can of paint (see photo below). Referencing the second photo below, pin #1 is on the right (where the red arrow is pointing), or furthest from the bunch of wires enternig the connector. Bottom line is, every single connection was good ... which is fantastic news since I wasn't looking forward to performing surgery on the wiring harness anyways!

ECU Cover Removal: Volvo 1800E ECU Cover Removal ECU Wiring Harness Connector: Volvo 1800E ECU Wiring Harness Connector

Sunday, February 21, 2010

PerTronix Ignitor Points-to-Electronic Ignition Conversion - Part 1

Alright ... same problem, different day. Engine starts & idles fine. Once warmed-up, it idles rough and eventually stalls. I've replaced the spark plugs, ignition wires, installed new thermostat and coolant temperature sensor in the engine block - no difference. The good news is there's only a finite number of possible causes and I've made a list of things to systematically check - it's only in the low hundreds. Among the items on my list are cold start valve leaks, vacuum leaks, MAPS sensor, fuel pressure, etc. There's also some suggestion on the forums that the gap on the breaker points may be closing down. Thus, being the last item on my list, and knowing my luck - it usually is the last thing that I'd check that's the culprit, I decided to skip all the other checks on my list for now and head straight for the last item on the list in an attempt to alter destiny.

Since I was already planning to perform a points-to-electronic ignition conversion and already have the PerTronix Ignitor module on hand, I decided to perform the upgrade which would eliminate the points & condensor ignition altogether, and hence any problems attributed to faulty points. Having spent a considerable amount of time on the forums trolling for installation notes specific to the Volvo 1800E with current sensing tachnometers, I was able to piece together shards of information into the following 2 wiring diagrams drawn up by my 3 year old daughter using crayons. Ok ... so I did do the drawings myself. The diagram on the left is how the stock wiring should look like for 1800E models. The one on the right is how the PerTronix module needs to be wired to get the current sensing tachnometer to work. My car does not have a ballast resistor going to the coil, so this implementation is specific to my set-up. Really simple - red PerTronix wire goes to ignition coil positive. Black PerTronix wire connects to white tach wire (or faded white on 40 year old cars!). The red PerTronix wire was not long enough to reach the coil on my car, and the black wire was way longer that it needed to be for my set-up, so I trimmed the black wire down and used the remains to lengthen the red wire for my specific application.

Stock Wiring diagram: Volvo 1800E Stock Ignition Wiring PerTronix Wiring Diagram: Volvo 1800E PerTronix Ignitor Wiring

The PerTronix installation walks you through removing the distributor cap, rotor, and points, followed by the installation of the module, and finally threading the wires through the distributor housing. Fuhgettaboutit! Save yourself the trouble - after removing the rotor and points, thread the wires through first before installing the module! Pictured below is the problematic somebitch! Attempting to thread the rubber grommet from the Pertronix module through the tiny hole (left by removing the condensor wire) from the inside of the distributor is an exercise you don't want to go through! If you follow PerTronix's instructions and install the module first before threading the wires and rubber grommet through, you'll find that there's not enough wiggle room to work the thing. In addition, the terminals on the PerTronix wires has barely enough room to clear the hole in the distributor housing. Not impossible - it's just a tight fit. Best to deal with it first before installing the module.

Problematic Somebitch: PerTronix Ignitor Electronic Ignition Module Wire Terminal Thru Distributor Housing: PerTronix Ignitor Wire Terminal

Here's how I did it: Remove the rubber donut completely. Thread it off the PerTronix wires and set it aside, but leave the coned-shaped other half attached to the wires. Next, thread the wires through the distributor housing (from the inside of the distributor of course). Apply dielectric grease all over the rubber donut ... inside the donut hole, inner lip, etc. The dielectric grease is just there as a lubricant to get the donut into the hole ... you can wipe off the mess later. Finally, thread the donut back onto the wires and ease it into hole of the distributor housing. I find that it's much easier to work with the rubber donut from the outside of the distributor. Apply pressure with thumb while slowly rotating the donut to get it to slip into the hole. Once inserted, thread the rest of the wires and the coned-shaped grommet through the hole in the donut to form a tight seal. You're done - follow the rest of the PerTronix manual to complete the rest of the installation.

Installing PerTronix Rubber Grommet: Installing PerTronix Rubber Grommet PerTronix Rubber Grommet Installed: PerTronix Rubber Grommet Installed

Although I do realize that it is necessary to reset the timing after the PerTronix installation as the triggering points are different for points vs. electronic module, I was hoping that the "old" timing would be "close enough". That way (assuming that this upgrade took care of the stalling problem), I would be able to drive to my mechanic and have the professionals adjust the timing with their fancy equipment. Boy, was I wrong! Timing was way off! The engine would barely stay running. Everything else worked fine - starts fine, and the tachometer works, indicating that the install was correct. All that is needed now is to adjust the timing .. which I'll save for next week's challenge.

Before: Volvo 1800E Stock Points & Condensor Ignition After: PerTronix Module Installed

I found an article on static timing a B20 engine on the Swedish Embassy website, which should prove useful for next week's challenge. I tried reading it briefly, but I think I broke a couple of my teeth in the process. I'll have to give it a thorough read this weekend ... right after I figure out what's TDC, what's 16 degrees BTC, what's a crankshaft, what's a timing cover, and what do timing marks look like or where to find them.

Saturday, February 20, 2010

New Thermostat & Engine Sensors

Well ... it's another weekend, and I'm back to troubleshooting my "warm engine poor idle followed by stalling" problem. Suspecting a bad coolant temperature sensor for the D-Jet EFI system, and not knowing the exact range of resistance values for a good sensor across a wider range of temperatures beyond the 50F - 104F outlined in the 1800E Service Manual (the "Green Book"), I had no other option but to order a new part. Besides, installing a new coolant temp sensor or removing the old one for testing would require draining coolant from the engine anyway, and because having new parts is waaaayyy better than money in the bank, I decided to replace the thermostat and the sender for the coolant temperature gauge as well.

Armed with a new and old coolant temp sensor, I took the opportunity to do some bench testing in the kitchen to satisfy my own curiosity. Drilling 2 holes in an empty food can, one for the sensor, and one for the food thermometer (classy ... I know!), I was able to submerge the contraption into a pot of water and take resistance readings with my multi-meter while slowly bringing the water to a boil. Results are as follows:

TempNew SensorOld Sensor
80F2000 ohms2500 ohms
90F1400 ohms1800 ohms
100F1000 ohms1400 ohms
110F1000 ohms1200 ohms
120F800 ohms1000 ohms
130F800 ohms800 ohms
140F600 ohms600 ohms
150F400 ohms500 ohms
160F350 ohms450 ohms
170F350 ohms400 ohms
180F260 ohms350 ohms
190F260 ohms300 ohms
200F250 ohms250 ohms

New Thermostat & Engine Sensors: Volvo 1800E Thermostat, Coolant Temperature Sensor, Coolant Temp Gauge Sender Testing the Coolant Temp Sensor: Testing Resistance of D-Jet Coolant Temperature Sensor

I began taking readings at room temperature water (80F according to the food thermometer) ... obviously a well calibrated instrument! You can count on those numbers ... trust me, I'm a lawyer! Anyway, although, the new and old sensors have different resistance values at the same temperatures, the one shared trait is that the resistance values do drop at increased temperatures. Not entirely sure if they need to hit an exact resistance value "on the money" at a given temperature or just be "within range", there's no way from looking at the table above for me to tell if the old sensor was really "bad" as I originally suspected. I say "originally", because installing the new thermostat and coolant temp sensor did absolutely nothing to change the running conditions of the engine - hence the old sensor should still be good ... unless it's the wiring from the sensor to the Electronic Control Unit (ECU) that's crap - I'll have to check that at a later time.

Acknowledgements:
  • Parts were purchased from iRoll Motors.
  • Funds for this failed attempt at engine diagnostics provided by Union Bank of California.
  • Food can provided by Hi-Top Fruit Cocktail
  • Food thermometer made in China.
  • Multi-meter also made in China.
  • This site was tested on animals. They didn't get it either.

Monday, February 15, 2010

Throttle Position Switch

Following-up on a lead that I read somewhere on the forums regarding a dirty Throttle Position Switch (TPS) leading to erratic idling and engine stalling, I decided to give my TPS a thorough cleaning to see if that solves my engine problem ... or at least eliminates the TPS as the source of the problem. At present, I'm not entirely sure of the mechanics of how it might contribute to the issues I'm having as I read about it late at night while I was half asleep, but detaching the plastic cover revealed some black scuff marks on the contacts as indicated by the red arrow in the first photo below. This was easily rubbed out with electronic contact cleaner and q-tips, followed by light dusting of the entire unit with the Dremel rotary tool with the soft bristle brush attachment.

Before: After:

Nope - didn't change a thing. Engine still starts up and idles fine until it warms-up, then it starts idling erratically and stalls. I didn't think it would work anyway since the symptoms are obviously heat related. I have my money on the coolant temperature sensor for now as the Fuel Injection Control Unit relies heavily on this very sensitive piece of equipment. Testing the resistance of the temperature sensor with a cold engine yielded a reading of 3000 ohms (within specs at 65 degrees room temperature). I took another reading when the engine was hot (after letting it run for a while until it stalled), and I got 0 ohms. I'm not entirely sure if its supposed to go all the way down to 0 since none of the resistance charts that I've seen for the temp sensor bother to show that range. Based on those readings, it does seem that the temp sensor is working like it ought to. However, it didn't occur to me while I was performing the test to see how quickly it reached 0 ohms. I'll do that this weekend, starting and stopping the engine at 1 minute intervals and then taking resistance measurements to see if I get a range of values.

Sunday, February 14, 2010

It's Alive!!!

Yup, the battery was at 85% of it's full charge. Took it to the AutoZone store this morning to have them charge it, and it's now registering 12.6 volts. Bench tested the new starter again with only the battery hooked-up and it spun each time. Reattached the starter to the engine, and the car fired right up! That little 1v or so sure made a huge difference! Now that the no-start problem has been solved, it's back to the original problem that started this whole mess - the engine idles ok, but when it warms up, the idle becomes erratic and I'll have to keep tapping the gas pedal to keep it from stalling. Once stalled-out, it takes a few tries to get it going again .. or sometimes not at all unless everything cools down.

The following series of 3 videos demonstrates the current running condition of my 1800E. The first video is the sound of the new Bosch permanent magnet starter in action. The 2nd video is the engine idling normally right after ignition and while it's warming up. The 3rd video is when the engine is all warmed-up and things start to head down the toilet.

Sound of New Starter:
Idling Normally:
Erratic Idle After Warm-Up:

Wednesday, January 6, 2010

Cooling System Update

The specifications for the 1800E states that the cooling system has a capacity of about 2.2 gallons. My car took about 1.5 gallons of coolant after the heater and radiator install, which can only mean there's still some air in the system that needs to be expelled. My car's manual did mention that it may take a long while of normal driving to completely bleed the system. I took the car out for a spin around the neighborhood this evening to get coolant circulating and to test the heater. Idle is still rough and erratic, presumably from condensation in the fuel system - so I dumped a bottle of iso-HEET water remover into the fuel tank, and hopefully that problem will go away after awhile. Oh, and I also bought a bottle of Chevron Techron to clean the fuel system and fuel injectors. The boys on the 1800List forum seem to go ape-shit on the stuff, so I thought "what the heck" - can't hurt right?

The good news is the heater works great, the blower is strong, and it's now pleasant to drive in the winter. The bad news - I discovered that once the engine reaches normal operating temperatures, it'll stall once my foot is off the gas pedal! Everything is fine when I'm driving except for when I take my foot of the gas pedal to slow down or stop at an intersection, the engine idles low and eventually stalls. This happened twice when I was driving around this evening. On the second time, the engine refused to start. Luckily, I was only 50 yards away from my driveway, so I pushed it the rest of the way home.

About a couple of hours later, the car started again on the first try. I suspect a bad thermostat - the one thing I didn't change when I overhauled the entire cooling system. The engine however, didn't show any signs of overheating - temmperature gauge normal, oil pressure normal, no steam or smoke from the engine. Who knows? I'll try replicating the problem another day.