ns87 Posted April 4, 2009 Report Share Posted April 4, 2009 Today. My battery is dead (hmmm, new alternator and newer battery). I jumped started it, and it immediately started, running poorly. As soon as we disconnected the jumper cables, it died. Every relay in the engine compartment took turns clicking. I started it (on it's own), and now all of the lights on my dash take turns blinking "Check gauges, SES, Low Coolant". It runs perfectly, then poorly, alternating at the same pace as the dash lights. Now it died and won't start. All the relays are clicking like crazy. Dead ECM? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 4, 2009 Report Share Posted April 4, 2009 ECMs arent that expensive... i'd replace it just in case. if that solves the isssue, congrats, if not, well at least thats one less thing that could go wrong sooner Quote Link to comment Share on other sites More sharing options...
White93z34 Posted April 4, 2009 Report Share Posted April 4, 2009 I doubt it. test your battery to be sure it is fully charged. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 4, 2009 Report Share Posted April 4, 2009 I doubt it. test your battery to be sure it is fully charged. that also would make sense. doesn't the ECM start to freak out once it hits like 9 volts or less? Quote Link to comment Share on other sites More sharing options...
jtwmechanic Posted April 4, 2009 Report Share Posted April 4, 2009 start with the basics before you jump to exspensive solutions. check and replace any bad or corroded battery terminals and cables, verify that you have a good completely charged battery. check all you fuses also they might be why it won't start. all these are common problems associated with your description. Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 5, 2009 Author Report Share Posted April 5, 2009 that also would make sense. doesn't the ECM start to freak out once it hits like 9 volts or less? Idk about that. I've had my dead alternator before, and the ecm never freaked out. I doubt it. test your battery to be sure it is fully charged. After a few no starts, the car magically started. My alt is putting out 14 volts. The battery is not dead. It has 11V-12V before I start the car. I checked the battery terminals and cables. They're good. When you turn the car to "ON", the check engine and low coolant light blink furiously. Then they steady out. Once the SES blinked slowly, and the fuel pump primed every time the light blinked. The low coolant light alternates blinking with the SES light. I reset the ECM. After I got it running, I just ran it for 10 minutes standing still. It kept throwing engine codes, stuttering, etc. It suddenly stopped, and I went for a 5 minute drive. On a hill, it randomly threw a SES light and stalled. It started up, and I parked it. Now it won't start. The GM paper clip trick doesn't put it into diagnostic mode. Either way, I'm not just going to throw parts at it. Everytime I buy a "Reman" part, it winds up dying in a few years. If the ECM is indeed dead, this "reman" one only lasted 5 years. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2009 Report Share Posted April 5, 2009 that also would make sense. doesn't the ECM start to freak out once it hits like 9 volts or less? Idk about that. I've had my dead alternator before, and the ecm never freaked out. i've seen a dying alt trying to run a car and voltage was dropping all the time and it eventually tried to idle at like 2500/3000 RPM and dropped and raised and a whole bunch of other issues(tranny in 3rd gear all the time, etc.). whole bunch of codes/dying/randomly not starting..... ECM is probably the issue, but its not necessarily dead, something might be preventing it from working correctly, though. what other issues have you had with the car? Quote Link to comment Share on other sites More sharing options...
Addicted To Boost Posted April 5, 2009 Report Share Posted April 5, 2009 The battery is not dead. It has 11V-12V before I start the car. Based on your description, I'd say it points to a dying ECM. However having 11-12V at the battery indicates that your battery is bad. A good battery should have 12.8 or more VDC at all times. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted April 5, 2009 Report Share Posted April 5, 2009 I would check your auxiliary post terminal nut for tightness before I proceeded any further. That little bugger can cause all sorts of electrical issues. Quote Link to comment Share on other sites More sharing options...
jtwmechanic Posted April 5, 2009 Report Share Posted April 5, 2009 have you went back through process of elimination to cypher why the battery was dead in the first place. generally if a battery goes dead while sitting with the ignition is off then 3 things come to mind short, bad battery, or you left something on. and jump starting can deal fatal blows to ecm's though very uncommon. shorts include bad grounds. Quote Link to comment Share on other sites More sharing options...
jman093 Posted April 5, 2009 Report Share Posted April 5, 2009 If you change the ECM, remember to swap the PROM chip. I forgot it on the Lumina and had to go back to the store and embarrassingly ask for the chip out of the core I gave them. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2009 Report Share Posted April 5, 2009 If you change the ECM, remember to swap the PROM chip. I forgot it on the Lumina and had to go back to the store and embarrassingly ask for the chip out of the core I gave them. or just have me burn a custom one for notsoslimshady76( with a 16 bank system for 16 different tunes on demand).... either way works, right? Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 5, 2009 Author Report Share Posted April 5, 2009 Thanks a lot guys for the input. The weather was really crappy today, so maybe I wasn't thinking 100% clearly in the cold. I'm going out tomorrow with a friend and going to look everything over ya'll suggested once again. If I can't find ANYTHING visibly wrong, I'll get an ECM. I'll keep you posted If you change the ECM, remember to swap the PROM chip. I forgot it on the Lumina and had to go back to the store and embarrassingly ask for the chip out of the core I gave them. or just have me burn a custom one for notsoslimshady76( with a 16 bank system for 16 different tunes on demand).... either way works, right? I didn't know you burned chips. Interesting Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2009 Report Share Posted April 5, 2009 Thanks a lot guys for the input. The weather was really crappy today, so maybe I wasn't thinking 100% clearly in the cold. I'm going out tomorrow with a friend and going to look everything over ya'll suggested once again. If I can't find ANYTHING visibly wrong, I'll get an ECM. I'll keep you posted If you change the ECM, remember to swap the PROM chip. I forgot it on the Lumina and had to go back to the store and embarrassingly ask for the chip out of the core I gave them. or just have me burn a custom one for notsoslimshady76( with a 16 bank system for 16 different tunes on demand).... either way works, right? I didn't know you burned chips. Interesting i'm getting to the point that i can burn chips for almost anything GM OBD1. notable exceptions include CCC setups (think quadrajets that get tuned by the ECU for fuel mixture from an oxygen sensor... its a bastard system). hell i've even got a thread going on to try to work out all the kinks of getting an obd1.5 vehicle tunable(granted its getting "downgraded" to obd1), but it hasn't been done all that often and almost anyone here with an 94-95 car knows what a pain in the ass obd1.5 is, hence the swap. that and is there anything obd2 that allows multiple tunes at the flick of a switch? thats why i choose obd1 over 2... Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 5, 2009 Author Report Share Posted April 5, 2009 Ok. There was a little corrosion on the battery terminals. Same with the AUX post. Cleaned that all up. -Battery cables are good. The battery is still a little bit low, but the car did eventually start. -I have spark. -I don't have a fuel pressure tester, but I don't think that's the problem. -I turned it to "ON" and the fuel pump wouldn't prime. Repeat. No prime. Then it primed, ran for about 10 seconds, died, and wouldn't start again. Now when I turn the car to "ON", the SES or Low coolant lights won't appear at all. Check gauges still illuminates. Still has spark. Primes every time now. I really think it's the ECM. How do I remove the ECM harness from the ECM? Do I *edit*push the tabs*edit* on those 4 connectors like any other engine connector? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 5, 2009 Report Share Posted April 5, 2009 well if its anything like my wifes 90GP or the 92 3.4GP PCM i have in front of me( and i'm fairly sure it is), thers going to be tabs on the top and bottom side of the connector. using one hand, squeeze like hell while simultaneusly(?) pulling gently on the wires running through the connectors with the other. its probably gonna be somewhat stuck, especially if the weatherpacking is doing its job. but that'll get it out Quote Link to comment Share on other sites More sharing options...
jtwmechanic Posted April 5, 2009 Report Share Posted April 5, 2009 exactly, also good time to check all the pins are not broken. Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 6, 2009 Author Report Share Posted April 6, 2009 Gave the computer a couple of wacks with my hand, reconnected it. It cranked a few times, then started and ran perfectly I figured this wouldn't last long, so I parked my car somewhere where I won't get a ticket. Sure enough by the time I got to the parking lot it almost died. I'm taking the bus home from school and leaving the car here. This gives me a chance to hit up the JY and get a used computer rather than an expensive new one. Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 6, 2009 Report Share Posted April 6, 2009 I'm taking the bus home from school and leaving the car here. This gives me a chance to hit up the JY and get a used computer rather than an expensive new one. good call. if that doesn't fix it, i would be suspicious of the PROM itself. Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 9, 2009 Author Report Share Posted April 9, 2009 Quick question, which ECMs are interchangable with mine? Here's my guess: 88-92 Cutlass Supreme, Grand Pix 90-92 Lumina 88-92 Regal ? Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 9, 2009 Report Share Posted April 9, 2009 Quick question, which ECMs are interchangable with mine? Here's my guess: 88-92 Cutlass Supreme, Grand Pix 90-92 Lumina 88-92 Regal ? i know for sure that 90-92 3.1s should have gotten the 1227727 or 1227730 ECM and runs on 88 code. there might be more, but i don't know. 7727s and 7730s were in just about anything so it shouldn't be that much trouble... Quote Link to comment Share on other sites More sharing options...
ns87 Posted April 13, 2009 Author Report Share Posted April 13, 2009 Well, this problem certainly has been fun. Installed a JY ecm from a grand prix with my engine/transmission combo. I haven't switched to my PROM chip because I think it might have been part of the problem. Unlike before, after a jumpstart the car starts (yes I will replace the battery) Everything was fine once I relearned the idle. Now, only when going up inclines, it does a hard sputter and simultaneously throws the low coolant light (the coolant level is fine). When the low coolant light isn't on, the car runs perfectly. Even better than when I bought it 5 years ago. No more flashing check engine lights. No more relays crazily clicking. I'm at my wits end. I don't even want to replace the battery, bc if I can't get this car working then there's no point. My 8 year warranty on the battery (only 3 years old) is useless since my tiny town doesn't have an Autozone. Quote Link to comment Share on other sites More sharing options...
Crazy K Posted April 13, 2009 Report Share Posted April 13, 2009 remove, clean, and reinstall the low coolant sensor. If a car has a bad battery it will not necessarily run correctly, even if jump started, the voltage to the ECM might fluctuate. Quote Link to comment Share on other sites More sharing options...
Night Fury Posted April 13, 2009 Report Share Posted April 13, 2009 Maybe that one is bad too! Quote Link to comment Share on other sites More sharing options...
jtwmechanic Posted April 13, 2009 Report Share Posted April 13, 2009 just don't drive up hills! but seriously what Crazy K said Quote Link to comment Share on other sites More sharing options...
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