I have been screwing with the injection on this car for at least a couple weeks now without any real success. Here are my experiences to date to remind me of all the little things I have found and fixed or perhaps broke.
Constructive criticism and comments appreciate.
Leroy, the Master Oil Change Technician that worked extensively on this car before me left a trail of missing washer, broken bolts and incorrect parts which have compounded the issues.
The first time I tried to start the car the fuel pump did not work. Found that the fuses were corroded in their holders. Cleaned/replaced them. I had a stock of Volvo fuses from many years ago. Then the fuel pump (FP) would run erratically and I changed the FP relay with a used one which also displayed erratic results. Removed the relay cover and cleaned the contact with 600 W/D paper. That seemed to fix that.
Then I found that the fuel distributor leaked from an attempted rebuild by Leroy. Sent the original distributor to JayTan for rebuild and calibration. $270, best deal on the Net if it really works.
At this point I found erratic power to the Lambda module. Took the System Relay apart and found a lot of corrosion. Cleaned it best I could and cleaned the contacts with the above W/D paper. That seemed to fix that.
The engine started at this point but ran with high rpm (1500) indicating a leak in the intake system. It started, ran and revved well but it had no power. Any significant throttle caused it to bog down in drive or reverse. While it would rev to red line it would not pull a hill. Exhaust does not seem restricted.
Not knowing if the Lambda module really worked and tripping upon a real bargain I purchased a correct PRV module (0 280 800 005) from a working PRV for $20. When replacing the one in the car I found that Leroy had installed a 4 cylinder module (0 280 800 033). That may have worked but perhaps not optimally.
Then found that the O2 sensor would not produce the required voltage. Max tuning of the CO screw in open loop only produced about 0.5v. Open loop means that the O2 sensor is disconnected from the Lambda module. Replaced with an OTB (other than Bosch) 02 sensor. That one produced 0.96v at max CO tuning.
At this point the engine started well, revved well, had no power and bogged with throttle.
Found an 1/8" 'T' connector that was broken and replaced. Found one of the 1/8" climate control vacuum hoses disconnected. Neither affected the engine condition.
Then I started dissembling/reassembling the entire air supply.
Found that the gasket between the upper and lower Air Flow Valve assembly was not well seated. Replaced.
Found that a bolt holding the 'ram horn' to the throttle body and to the intake manifold was too long, bottomed into the blind hole and did not seal one half of one side of the connection. Thanks Leroy! The bolt belonged in the throttle linkage assembly. Replaced the original gaskets that had been disturbed but not replaced.
Found that Leroy left out a couple of the washers on the throttle body to air flow assembly. Not a big problem but evidence that he had been there.
Disassembled the distributor and found new spark plug wires and rotor. The advance plate moved easily but the shaft oil pad was completely dry indicating that the distributor had been open but by not by anyone that knew about Volvo maintenance.
After all this effort and with careful attention to ensuring that all potential vacuum leaks are addressed the engine exhibits, by high rpm, even more vacuum leaks. RPM is now at 2k. Note that this chance from 1000 to 2000 rpm is in the wrong direction and I do not know why.
With advice from my new BFF, John Lane, adjusted the CO screw to produce 0.7v this afternoon. The voltage was not really stable but varied from 0.5 to 0.8v based on very tiny adjustments to the CO screw. Removing the 3mm Allen wrench caused the voltage to vary significantly so I had to adjust, close the 3/16? port, measure and adjust again . . . several times.
Still no cigar!
Bottom line is that the engine starts, runs, revs very well. Idle is 2k rpm. No power, bogs down with throttle operation.
Any suggestions appreciated.