digitaloutsider Posted June 1, 2012 Report Share Posted June 1, 2012 Okay, as some of you know, ever since last year, the Lumina has had a stalling issue. This existed on the previous motor and because of a copious loss of coolant internally and a severe overheating problem, I replaced the engine (amongst a bunch of other stuff). Upon getting the car back together, the stalling problem was honestly worse and since then, I haven't been able to drive it. I have over a grand of new parts in the car, none of which I can use. I've been trying to flip the piece of shit, but because it stalls, no one wants it (or people want to drive it an insanely long distance). Here is a (what I believe to be) complete list of replaced parts SINCE the engine swap: IAC (a few times) TPS ECM MEMCAL MAP ICM All 3 coilpacks CPS Battery Alternator (old one checked out as good) Big 3 (4 gauge) everywhere Blocked off EGR It just seems like it never wants to catch itself. Like if you're driving and push the clutch in, rather than holding the revs up as it should, it just tanks and then starts fluctuating and if you come to a stop, it usually stalls. The IAC wiring checked out OK. I tried swapping Chris' ECM and MEMCAL and his IAC and the car ran fine for a little while, but as it got hotter, it stumbled again and stalled a couple of times. The car runs nearly perfectly if it's cold. Let it warm up for 10 minutes and it will stall coming out of the driveway. It also seems to pick and choose when it wants to hold the revs up. With Chris' ECM it did this for the first few minutes, then stopped. I don't know the reasoning behind that. The O2 sensor was replaced soon after I first bought the car (another stalling issue.. turned out to be the ICM and coils). Fuel filter was replaced then, too. Plugs and wires have less than 10K on them. The car also seems to have a problem coping with loads on the electrical system. If the headlights and cooling fans are on, the voltage gauge reads low at idle and this will typically cause the car to stall faster. Again, the alternator and battery are both good, both have been checked. I have a couple year old Red Top in there now, but it did the same thing on a brand new Everstart Maxx battery that is now running strong in my GTP. I'm simply at a loss for where to go from here. There are literally no more parts I can throw at it, and I'm just frustrated. I want to sell it, but no one wants to buy a car that won't stay running. Next stop is the crusher or a nice steep cliff if I can't figure this shit out. Any ideas? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted June 1, 2012 Report Share Posted June 1, 2012 I'm kind of thinking, why not put my ECM back in your car, put your chip in it. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted June 1, 2012 Report Share Posted June 1, 2012 I'm going to be taking a wild guess here. This by all rights, sounds like a voltage issue. When the fans come on, they're obviously drawing a LOT of current. Could this momentary drop in voltage be causing a weak fuel pump to slow or stop? Quote Link to comment Share on other sites More sharing options...
skitchin Posted June 1, 2012 Report Share Posted June 1, 2012 God damn't hit the back button trying to reply after typing a whole bunch... Sounds like a pita. I'm guessing the battery holds it's charge and you're not having to jump it. It's possible though that something is draining the power, either controlled by the accessory switch or the ignition switch. There might be a better way, but you could put the key in accessory mode and watch a voltmeter for a few minutes. Not sure how Could also be a fueling issue; a clog somewhere, bad fuel pump, or bad pressure regulator can cause intermittent misfires. Hope you get her going, think I speak for everyone when I say we'll try the best we can to help you along the way. Would be a great story to see a simple fix get this car back on the road. Quote Link to comment Share on other sites More sharing options...
Penglii Posted June 2, 2012 Report Share Posted June 2, 2012 Maybe a dumbass question... but have you checked the condition of the fuel injector o-rings? I've had a few rough running & stalling experiences that have tought me to always check the injector seals... Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted June 2, 2012 Report Share Posted June 2, 2012 Do you have a laptop where you could datalog it? If you can then you can record when it stalls and pause it and look at all the readings to see what is out of place. No sense on throwing more parts at it if you don't know what's wrong. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 I had the same problem. I solved it by tuning it I am very proud to say. I think its to do with the ethanol gas being an entirely different fuel than 20 years ago. I was looking for my old thread from 2010 for mach 5 the other day and noticed there being a bunch of similar description and they all said the same thing, oh I fixed it.. oops it's back . my 5th IAC motor now. it can be very frustrating. fortunately GM can not be blamed because there is a solution to the problem. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 ...more people have this problem than actually admit to it BTW. I know this because I didn't complain too much about it on the forums, I would seek out help from other tuning guys on here under the radar until I found out how exactly to tune for it. I also spent many afternoons staring at the XDF for 8F in TP5 and found some interesting looking stuff after awhile. Quote Link to comment Share on other sites More sharing options...
topless94style2 Posted June 2, 2012 Report Share Posted June 2, 2012 Fuel pressure regulator could cause this, Pull your plugs do they have signs of too much fuel? but The electrical thing points me to fuelpump considering spark seems to have been taken care of. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 yeah, put a fuel gauge on there and while monitoring the gauge, datalog it Quote Link to comment Share on other sites More sharing options...
jman093 Posted June 2, 2012 Report Share Posted June 2, 2012 The O2 sensor was replaced soon after I first bought the car (another stalling issue.. turned out to be the ICM and coils). Fuel filter was replaced then, too. Plugs and wires have less than 10K on them. The car also seems to have a problem coping with loads on the electrical system. If the headlights and cooling fans are on, the voltage gauge reads low at idle and this will typically cause the car to stall faster. Again, the alternator and battery are both good, both have been checked. I have a couple year old Red Top in there now, but it did the same thing on a brand new Everstart Maxx battery that is now running strong in my GTP. If you have some electrical issues take care of that first. Maybe it has nothing to do with the stalling, but it's useless to keep throwing different parts at it when there is a known issue that needs taken care of. I'd guess there's some sort of problem with the Big 3 upgrade, a bad block ground, or something. I would voltage drop test all battery, charging and ground system wires. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 I agree that its a voltage problem. voltage can be monitored while datalogging. the voltage can be seen dropping below a certain rpm. below that certain RPM the pulley is not turning the alt fast enough to put out the electricity the car needs to run smooth. this is why we tune the throttle follower to maintain a higher rpm that will sustain the electrical load. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted June 2, 2012 Report Share Posted June 2, 2012 ...more people have this problem than actually admit to it BTW. I will be one of the first. My Euro 3.4 will stall sometimes when the fan kicks on, or when there is a serious drop when jumpstarting my lawn mower. Quote Link to comment Share on other sites More sharing options...
Night Fury Posted June 2, 2012 Report Share Posted June 2, 2012 My 91 stalls a lot, but not due to voltage drops. Just randomly, like you said, sometimes it just doesn't 'catch' in time when you press in the clutch Quote Link to comment Share on other sites More sharing options...
Schurkey Posted June 2, 2012 Report Share Posted June 2, 2012 (edited) Okay, as some of you know, ever since last year, the Lumina has had a stalling issue. This existed on the previous motor and because of a copious loss of coolant internally and a severe overheating problem, I replaced the engine (amongst a bunch of other stuff). Upon getting the car back together, the stalling problem was honestly worse and since then, I haven't been able to drive it. I have over a grand of new parts in the car, none of which I can use. I've been trying to flip the piece of shit, but because it stalls, no one wants it (or people want to drive it an insanely long distance). Here is a (what I believe to be) complete list of replaced parts SINCE the engine swap: IAC (a few times) TPS ECM MEMCAL MAP ICM All 3 coilpacks CPS Battery Alternator (old one checked out as good) Big 3 (4 gauge) everywhere Blocked off EGR You consumed a bunch of coolant, but haven't replaced the O2 sensor? The sensor is perhaps poisoned. It just seems like it never wants to catch itself. Like if you're driving and push the clutch in, rather than holding the revs up as it should, it just tanks and then starts fluctuating and if you come to a stop, it usually stalls. The IAC wiring checked out OK. I tried swapping Chris' ECM and MEMCAL and his IAC and the car ran fine for a little while, but as it got hotter, it stumbled again and stalled a couple of times. The car runs nearly perfectly if it's cold. Let it warm up for 10 minutes and it will stall coming out of the driveway. It also seems to pick and choose when it wants to hold the revs up. With Chris' ECM it did this for the first few minutes, then stopped. I don't know the reasoning behind that. The O2 sensor was replaced soon after I first bought the car (another stalling issue.. turned out to be the ICM and coils). Fuel filter was replaced then, too. Plugs and wires have less than 10K on them. The car also seems to have a problem coping with loads on the electrical system. If the headlights and cooling fans are on, the voltage gauge reads low at idle and this will typically cause the car to stall faster. Again, the alternator and battery are both good, both have been checked. I have a couple year old Red Top in there now, but it did the same thing on a brand new Everstart Maxx battery that is now running strong in my GTP. I'm simply at a loss for where to go from here. There are literally no more parts I can throw at it, and I'm just frustrated. I want to sell it, but no one wants to buy a car that won't stay running. Next stop is the crusher or a nice steep cliff if I can't figure this shit out. Any ideas? This seems to be somewhat temperature-related, and I don't see a coolant temperature sensor on your list of replaced parts. Have you verified what the computer is receiving for temperature information? 1. Have you done any diagnosis/inspection with a scan tool connected? That's a conspicuous absence in your description, and the SECOND thing that should have been done. Not using a scan tool is pissing in the dark, you can replace parts all day long and twice on the weekend--but unless you get lucky, all you're doing is spending money and wasting time. 2. FIRST PRIORITY is getting the voltage where it needs to be. You say the alternator and battery is good, has been tested. I'd like to know HOW those parts were tested, and what the results were. Any bonehead can put a voltmeter on the battery and claim it's been tested and passed. Doesn't mean it will pass a load-test, or will hold a charge. A voltmeter can similarly show decent voltage and current, but if the diodes are allowing too much Alternating Current into the system (ripple) the AC voltage can make the computer crazy. A potential issue is voltage drop into the passenger compartment--maybe the dashboard (and therefore the voltmeter) is starving for current so the voltage drops??? 3. I have no idea why you'd disable the EGR. What is that supposed to accomplish beyond increased emissions and potentially greater tendency to detonation? Edited June 2, 2012 by Schurkey Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 My 91 stalls a lot, but not due to voltage drops. Just randomly, like you said, sometimes it just doesn't 'catch' in time when you press in the clutch I am curious which table or "cell" the stalling event occurs. also when it "catches" what is the IAC position at, and lowest RPM it drops to. at that lowest point before the IAC starts to move up again, what is the average lowest voltage at the dip? does it stay at above 12 volts when the random stall happens, or has it even been datalogged? Quote Link to comment Share on other sites More sharing options...
Schurkey Posted June 2, 2012 Report Share Posted June 2, 2012 Have you ever tested the fuel pressure? My '92 Lumina is having intermittent running problems. Sometimes it runs great, sometimes it stalls or misfires so bad it's hardly drivable. Fuel pressure gauge shows rapid fluctuation between about 37-to-41 psi. The needle bounces so fast it's just a blur. I'd really like to see steady pressure from 41 to 47 psi. Fuel pump on order... Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted June 2, 2012 Report Share Posted June 2, 2012 (edited) I datalogged mine while it stalled with a FP gauge on the windshield. watched the voltage continually drop below 12 volts until the puel pump stuttered to 20-30 psi while the car was still running. then it died at like 16 psi. replaced the fuel pump and it stalled still. wildly between 37-41 psi would have been great! Edited June 2, 2012 by Garrett Powered Quote Link to comment Share on other sites More sharing options...
topless94style2 Posted June 3, 2012 Report Share Posted June 3, 2012 You consumed a bunch of coolant, but haven't replaced the O2 sensor? The sensor is perhaps poisoned. This seems to be somewhat temperature-related, and I don't see a coolant temperature sensor on your list of replaced parts. Have you verified what the computer is receiving for temperature information? 1. Have you done any diagnosis/inspection with a scan tool connected? That's a conspicuous absence in your description, and the SECOND thing that should have been done. Not using a scan tool is pissing in the dark, you can replace parts all day long and twice on the weekend--but unless you get lucky, all you're doing is spending money and wasting time. 2. FIRST PRIORITY is getting the voltage where it needs to be. You say the alternator and battery is good, has been tested. I'd like to know HOW those parts were tested, and what the results were. Any bonehead can put a voltmeter on the battery and claim it's been tested and passed. Doesn't mean it will pass a load-test, or will hold a charge. A voltmeter can similarly show decent voltage and current, but if the diodes are allowing too much Alternating Current into the system (ripple) the AC voltage can make the computer crazy. A potential issue is voltage drop into the passenger compartment--maybe the dashboard (and therefore the voltmeter) is starving for current so the voltage drops??? 3. I have no idea why you'd disable the EGR. What is that supposed to accomplish beyond increased emissions and potentially greater tendency to detonation? Come on now a scan tool is not required to diagnose some problems. We can narrow this down by simple diagnostics. Given he has ample air and ignition we can examine the fuel system. If no scan tool is available i suggest again pulling the plugs to understand the fuel condition especially if we cannot find any check engine codes. Quote Link to comment Share on other sites More sharing options...
digitaloutsider Posted June 4, 2012 Author Report Share Posted June 4, 2012 Scanned the car with TunerPro RT, it did help to rule out voltage being an issue. I completely blocked off the EGR because it's disabled in my chip. My concern was that perhaps it was staying halfway open and letting in air the engine wasn't expecting. The alt was new and tested before it was installed on the car. The car was load tested with the prior battery and then with the new battery. It's not my first rodeo. Anyhow, I've figured out most of the problem. The don't-ever-fuck-with-this idle set screw was completely out of whack. I'm assuming someone dicked with this at some point when it was in Sam's car. Anyway, what was happening is that the IAC couldn't compensate quick enough at idle to keep the engine running. It would try as it was just beginning to stall, but to no avail. I adjusted it and now it's much better. It still isn't perfect and I need to toy with it some more, but it's only stalling about 5% of the time now, and about half of the time, it doesn't dip at all and runs totally perfectly, even with heavy load on the car. However, from sitting, the battery has finally begun to get weak. It barely, barely passed a load test today. It'll likely need to be replaced soon. Either way, I'm happy to finally be making some headway with this stupid piece of shit. Thanks for the suggestions, guys! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.