940 (1994) fuel too rich? weird issues also between 2 cars

[wintersun]

A local mechanic replied to a plea I posted on Craigslist today. It seems the difference was related to production dates. The CA car was 10/93, the FL car was 6/94. He came over to check it out and showed me and my dad the different MAF systems (big bosch box on the CA car, little plug on the FL car) and coil vs control module on CA vs FL car and some other differences)

When he messed with the control module connection on the FL car, wiggling it around and such was the only time we ever got fire to the engine and started it. There was lots of backfire and skipping. It sounded like it was out of time when it was running during that brief time, too. He advised me to go to the local pull a part and get a module to switch out, which I'll try to do this week, since I can't get one from the car I'd hoped to use as a donor.

[wintersun]

I looked at six Volvo 940 cars at the Upick today and none of them had my engine config and therefore I could not pull the control module (pictured at link below) from any of them
http://sd.autohausaz.com/autohausaz/ima ... 867OES.JPG

So. Before I order a $130 part, can anyone help me with the On board diagnostics so that I can be sure that what I order will help me get the car on the road? I'm already stuck with one car that I cannot use as a donor car.

[billofdurham]

You can find out how to use the On-Board Diagnostic (OBD) here.

The 240, 740 and 940 have the same unit but the 940 has a couple of codes less than what is shown. Any codes you don't understand, post back.

Bill.

[wintersun]

Well, it's a small town and I was feeling confrontational but I'm also pretty nice so I called the guy who sold me the car. Told him I needed an ignition control module and asked him if he had a source for used parts, and when he mentioned that he knows the u-pick has six 940s with regina injection systems in them, (I went to one u-pick yesterday that had six 940s but they all had the bosch) I asked couldn't he pick one up for me when he goes again since I have my 2 year old with me all the time and it will be very hard for me to get there (an hour away) and pull the part.

He ended up coming over, looking over the car- did verify that the module is shorting out and I do need the part (he will get it for me tomorrow) and he also got up under my other 940 and agreed with my original hypothesis that the trans is not gone in it, but that the filter is not seated in it and the shifter isn't connected. So that car might not be a parter after all, we might actually have that one as a runner.

will post back if 1) this guy shows up with my part tomorrow and 2) it solves the problem. It should. The car was running and running well when I bought it. Both my brother and my dad, who are mechanics, drove it before I bought it, so... maybe it IS just a case of "sometimes things just break"

[wintersun]

I can't print out the OBD stuff. the replacement ICM did not do the trick. there is spark. I was advised to take speed sensor circuit from my running car and move it to the non running car to test.

[wintersun]

RPM sensor. Switched them between running and not running car and that did the trick. Car #2 has been idling perfectly in the driveway for 45 minutes. Lovely. I spent 35 dollars on the control module I didn't need, but that's OK, now I a) have a spare and b) know how to change out the rpm sensor.