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:

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:

ECU Wiring Harness Connector: