Sorry for the novel, but THANK YOU to all who posted about how to convert LH2.0 to LH2.2.

Had to restart car 3 or 4 times when cold. Would hesitate like it was fuel starved and backfire through the intake on acceleration until the temp gauge reached 9:00, then pick up and accelerate like it should. Even after complete warm up you could still feel power kick in and out under light load. Leads me to believe that the ECU was making an effort but the AMM was starting to fail.

Tuned it up, cleaned AMM, IAC, flame trap, separator box and throttle body, reset TPS, replaced ECT, knock, O2 sensors, intake manifold gasket and injector seals with no difference in performance. All wiring harnesses look new (replaced a couple of owners ago).

After reading about how easy it would be to make the switch from 2.0 to 2.2 I decided to give it a try since I had an 007 AMM and 511 ECU stored away after sending my beloved 86 CNG sedan (originally from Boston.. so no floor boards) to Volvo Heaven.

Re-pinning the AMM plug only took a few minutes (wire clips came out easily). Put the 007 in place of the 002, hooked it up, replaced the 510 with the 511 and hit the key.

Cold hesitation is gone, no more spark knock, no backfiring through the intake, accelerates smoothly and no more power fluctuations under load. Idle is fairly steady and the timing is now spot on with no more jumping around as previously seen with a timing light. Looks like Santa Claus gave me a new to me (again) car for Christmas.

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Harold Thompson '84 245 Virgos