'92 740 suddenly dies.....

Mar 03, 2007 2 Replies

It will be running fine, and then it just shuts off. Usually after it sits there for a day, it will start again. Thought it was fuel pump or pressure problem. It has a new fuel pump (not the one in tank...the other one), filter, and a new fuel control relay. The plugs are firing after it dies, its not ignition. The car has been with a very exerienced pro mechanic now for over 2 weeks, and he can't figure it out. NO codes are set. The mechanic says it still has fuel pressure when it dies. He pulled out one or more plugs, and said that they are soaked with gas, so he thinks the engine is flooding out. I didn't think this would happen with injected engines....it just dying like you switched off the ignition key.



If I remember right, this car has a separate fuel control (Jetronic) computer module. (or maybe I'm confusing with my 88 Camry?) Maybe if it is intmt. failing, the injectors would be stuck open, or open way too long, flooding the cylinders with gas? But there is no code being set for a faulty fuel ctrl computer. It costs big bucks to buy a new one, and then we might find its not that!



I don't know if the mechanic has put noid lights on the injectors when it has failed, that is what I'd do...and try reseating the ECM connector if the noid lights don't indicate a failure.



Ideas?


When it dies, try unplugging the air mass meter and see if it starts back up. That can fail in a way that makes the mixture go full rich, though it's not common.

I think your car is similar to my '89 240... I had a problem with it running erratically a year or so ago. Replaced the fuel pump, still wouldn't run reliably. No codes. Then I checked the large plug-in fuse located along the left (driver's) fender, right near the spark coil. It is apparently the main fuse for the engine computer and such. Turned out the socket it was plugged into had broken apart! I was able to push the connectors back onto the fuse spades, and the car ran (and has been running) fine since. I know from experience that if you pull the fuse, you turn off the CHECK ENGINE light and also lose the codes, so perhaps your problem is similar? Wouldn't hurt to check the fuse, socket, and associated wiring anyway.... I think it is about 30 amp, and mounted at the top of the fender, right above the wheel.....

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