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:

Close-Up:

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:

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.

Since 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.