Metro Posted October 3, 2005 Share Posted October 3, 2005 I've had nothing but problems lately. My new issue is the ecu appears to be turning on and off randomly. I just noticed it the other day and it appears to be the cause of my most recent problems. At least, I think the ecu is shutting off. The green LED flickers and the fuel pump relay turns off and on, then the engine stumbles. It's not like when the O2 sensor is up to temp, it's like when you first turn the key and the LED turns on, then off when the engine has started. My first thought was a bad connection to the ecu power. I watched the voltage to the ECU at the ECU's plug and there wasn't any change when the LED blinked and the FP relay turned on/off. I checked the voltage from the CAS to see if it was cutting out, and again, it looked steady. Just for the hell of it, I redid all the wiring under the dash, added a few extra grounds and still no dice. My thinking is, the ecu thinks the car is stalling so it shuts down, then starting up again instantaneously. Anyone have any ideas of what could be causing this? Unfortunately I don't have the FSM for this year, so I can't diagnose this any better myself. I've previously checked the AFM, TPS, CHTS like the haynes manual says and they all are fine. I also have new injectors, new cap, new rotor, new plugs, and new wires. This is just about my last resort on fixing this. The car has been down for a month now due to mysterious problems and is continually getting worse. My next step is to trash the factory EFI and go ahead with my plans to run megasquirt, which is what I've wanted to do since day one, but I was hoping I could get the factory efi working. I know the engine is sound mechanically, so I think I might just go ahead and switch. But if anyone has any ideas, I'll try them. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted October 3, 2005 Share Posted October 3, 2005 It could have something to do the the efi relay. When you turn the key to on, the ecu sends a signal to the efi relay to turn on the afm and cas, but it also sends a signal back to the ecu to tell the main circuits to turn on. It's almost like as if the ecu has two levels of being "turned on" Anyway, perhaps there is a bad connection in there somewhere or the efi relay isn't working properly anymore. Quote Link to comment Share on other sites More sharing options...
Metro Posted October 4, 2005 Author Share Posted October 4, 2005 My first thought was a bad connection too, so I checked for that. Maybe I wasn't clear before. I checked the power at the ecu (the BW wire which is after the FI relay) while it was running to see if there were any fluctuations and there were none. So as far as I can tell, the ecu is getting constant power like it should. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted October 4, 2005 Share Posted October 4, 2005 yes but even if you have good connections your efi relay could still be flakey Quote Link to comment Share on other sites More sharing options...
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