Testing AFM and ECU Out of Car

[cslayman]

Hi,

I have a 1988 740 Turbo Wagon with manual transmission and 215,000 miles. I've just install a 1994 B230FT motor with turbo that I got from the wreaking yard (it was running in the car it came out of, so I know the motor is good).

I've intalled all the accessories from the 1988 car including fuel injectors, AFM and ECU since the 1994 car had a different harness and electrical system. When I try to start the car, the mixture is way too rich. The motor runs for a few seconds and then stalls. It will no start again unless I disconnect the fuel injection electrical leads and crank the engine. It will start again and run a few more seconds on the excess fuel left in the manifold. I picked up a second set of injectors and another AFM from the wrecking yard, but the symptoms are the same. I haven't picked up a spare ECU from the wreckers yet. I'd like to be a little more methodical in my next steps rather than continue to "swap 'til you drop". Is there any service that will test the AFM and ECU outside the car? Most dealers and repair shops say "bring the car in". But it's not running and I hate to tow it to garage only to have them say "Sorry, we can't find a problem".

I live in San Jose, CA. A local service would be great, but I'm willing to mail the AFM and ECU out to a diagnostic service. I figure I'll send my spare set of injectors out for refurbishing and calibration since they have over 200,000 miles on them anyway.

Thanks,
Charlie Slayman
1988 740 Turbo Wagon

[cslayman]

To All Interested in This Post,

Check out the posting "Troubleshooting Guide or Tutorial for 1988 Jetronic?" Bill of Durham was kind enough to attach a guide that has many of the details of testing the LH Jetronic on the 1988 model year. Many of the tests can be done with an ohmmeter and voltmeter with the parts on the car. The guide is also very useful in discussing wiring and test points. I highly recommend it! I was totally confused by the Haynes Manual since it covered such a broad range of years and the electrical diagrams and terms were confusing. The documents in the other post are specific and accurate for the 1988 model year.

If you do want to test the LH Jetronic unit out of the car, there are services online that you can mail your computer to for test and/or repair. (I couldn't find any local services.) For example, http://www.ecmoutlet.com/volvo.html or www.ecmtogo.com. (This is not an endorsement, just an indication that there are services that do this type of work.)

A WORD OF WARNING: All the experts I talked to said they have see a total of 1 Jetronic unit fail. So that is the last thing you should look at. If you follow the troubleshooting tests in the other post, you will probably find your problem lies elsewhere.

Cheers,
Charlie

[billofdurham]

Charlie,

Thank you for the endorsement. I missed this post as I was away in Europe when you placed it. Had I seen it earlier I would have put the trouble shooter on then.

Bill.