SmoothSteve3 Posted June 12, 2004 Report Posted June 12, 2004 Ok, so apparently I offended some people with my last thread talking about how my mechanics shop was taking me for a ride. I'm sorry, its just a little venting.....I certainly didn't mean to offend any of my w-body buddies. But all of the hard feelings aside, here's an update: Tonight I replaced the ECM with a new unit. I thought that perhaps my problem was solved, cause it seemed to do well for the first 15 minutes or so that it idled....but I was wrong. I went to drive it around the neighborhood, and the old problem came back immediately. I'm going to try my best to describe it....but without a sound clip, its gonna be hard. The car (90' lumina 3.1) will be idling smooth, and then all of a sudden the rpms will drop significantly......but not to the point of dying. The car hasn't died on me once through this whole ordeal. But the rpms get low enough that you can feel and hear the pulse of the engine quite defined. And then all of a sudden, it will just recover and act all normal again. It doesn't matter what gear I'm in, or if i'm accelerating, decelerating, or just coasting. To me, this sounds like an electrical problem of some sort since it is so "off and on", and the car shows no bad traits when idling smoothly. Here's all that I've done to it within the last 12 months New IAC New O2 sensor New MAP sensor New crankshaft position sensor New spark plugs New spark plug wires New alternator New ECM (used old PROM chip) New Cat. Converter One thing I haven't investigated is the fuel system or the Ignition Control Module Thats it......any ideas guys? Thanks a million in advance SmoothSteve Quote
DaveFromColorado Posted June 12, 2004 Report Posted June 12, 2004 try a "wiggle" test while the engine is ideling, just grab different wires and wiggle them and see if the problem happens at that moment, sometimes* that works. --Dave Quote
91oldscutlass Posted June 12, 2004 Report Posted June 12, 2004 I still say it sounds like the trouble I was haveing with my car...it ended up being the injectors. Quote
SmoothSteve3 Posted June 12, 2004 Author Report Posted June 12, 2004 Well, for all I know, it could be the fuel injectors. I'd certainly hope not.....since they're frickin expensive......but it could be them I guess. What exactly was the problem with your injectors? Did it require all six of them to be replaced? Anyhow, it gonna be impossible to concentrate at work today....I'll be thinking of my car too much. If you guys have any other suggesstions, please let me know! Thanks! SmoothSteve Quote
sonyman87 Posted June 12, 2004 Report Posted June 12, 2004 its not likely all 6 injectors go bad at the same time.. dose it happen in park also? it could also be an accesory like your A/C kicking on and off or your Power stearing pump.. inplug your A/C clutch see if that helps to be sure your clutch disengauged by looking closely at the wheel and see if the middle is spinning also. If it is then while unpluged then your ac may be the problem overcharging your system causing lots of resistance. Quote
91oldscutlass Posted June 12, 2004 Report Posted June 12, 2004 Well, for all I know, it could be the fuel injectors. I'd certainly hope not.....since they're frickin expensive......but it could be them I guess. What exactly was the problem with your injectors? Did it require all six of them to be replaced? Anyhow, it gonna be impossible to concentrate at work today....I'll be thinking of my car too much. If you guys have any other suggesstions, please let me know! Thanks! SmoothSteve My car didnt start one day after everthing else got replaced..I replaced all 6 of them and havent had anymore problems. Quote
SmoothSteve3 Posted June 12, 2004 Author Report Posted June 12, 2004 Here's an update: I've been able to narrow it down to when ever the car gets hot....for instance...if i drive all around with my fans on, then it wont do it. But if i drive around with them off, then it will eventually do it for me. It does it in park, neutral, reverse, and drive Quote
Baddflash Posted June 12, 2004 Report Posted June 12, 2004 From experience with various cars seeing as it's heat related I would say it could be the ICM and/or coil/coils. Does it do it for any extended period of time or is it just for brief moments? How does it react to your input when it does this? How does the car react under heavy load, after and episode have you tried driving it hard to see what it does? Quote
DaveFromColorado Posted June 12, 2004 Report Posted June 12, 2004 injectors tend to be really heat sensative. --Dave. Quote
SmoothSteve3 Posted June 12, 2004 Author Report Posted June 12, 2004 yeah.....the ignition is certainly a possibility. It will do this in for a time period of anywhere from a few seconds to like 10 minutes. Like I said, very inconsistent. It will do it under a load to. In fact, it doesn't matter what gear, or how hard i'm accelerating....it will still do it. I still am going to say that its heat related. I seriously doubt that this is related....but on the way home from work 15 minutes ago, I noticed a screaming noise coming from under my hood. I just replaced the serpintine belt last night......do new belts squeal for awhile? I dont think its the alternator......its pretty new......and I know what that kind of sqeal sounds like. Just a side note. Thanks for the suggesstions.....keep em coming! SmoothSteve Quote
topless94style Posted June 13, 2004 Report Posted June 13, 2004 If it is your injectors, just pull a set from a junkyard for cheap, and then send them out to witch hunter and for a little over $100 youll havea pretty much brand new set of injectors. I think its either that or the ICM Quote
Gearhead43 Posted June 13, 2004 Report Posted June 13, 2004 AutoZone can test the ICM for ya.. they should do about 3 or 4 test if the first 2 pass cuz its when ICM gets hot is when the Problem accurs sometimes. Do a Slap test on the ECM.... while the car is idling.. and see if anything changes. Could be coil paks too Quote
SmoothSteve3 Posted June 13, 2004 Author Report Posted June 13, 2004 Here's another update: Last night, I took my dad for a ride in the car so that he could get a feel for what it was doing. When we were done, he told me to jump the diagnostic terminal to see if I could get any codes. Now keep in mind that I had already tried this atleast 5 other times earlier yesterday...and I had gotten nothing. Well, this time I got a 33...which is the MAP sensor (high voltage, low vacuum). Now what baffles me, is that I just replaced the MAP sensor like 8 months ago....it shouldn't be fried yet. So today I ripped out the map sensor completly and started the car with it disconnected. The engine did the exact same thing that its been doing for the past few days. Does this mean that the MAP sensor is completly unfunctional, and that could be my problem? Or does that mean that the MAP sensor has nothing to do with my problem.... I still haven't ruled out injectors, ICM, or the coil packs.... Thanks guys! I'll get her running again soon.....I hope.... SmoothSteve Quote
Gearhead43 Posted June 13, 2004 Report Posted June 13, 2004 NO.. The MAP sensor Could be FINE... It still could be a spark problem.. When whatever is causing the problem hits, it causes a MISFIRE.. If the misfire is bad enough the engine will lose Vaccum. Since the MAP runs off Engine Vaccum, it's possible that the misfire could be the reason for the MAP code. At this point you should get someone with a ScanTool and hook it up, drive the car around with the ScanTool in Record MODE. Til when it does what you see what it does.. Then play it back to see what the readings are. I'm still looking at a bad ICM, Coil , or Crank Position Sensor. Quote
SmoothSteve3 Posted June 13, 2004 Author Report Posted June 13, 2004 man....i dunno what I'd do without you guys.... thanks gearhead....I would never have thought of that. Unfortunately, the only person I know with a scan tool is out of town on a cruise for the next 8 days.....lucky bastard.... Well, I replace the cranksensor like 6 months ago with one of the new plastic ones with the metal housing.....so hopefully it will come out easier next time it dies...but it shouldn't have gone bad already. I'm probably just gonna have to give in and take it to a gm dealership to see what they have to say....I've already spent 300 dollars trying to fix this problem, and nothing has even helped a bit. If i took it to the dealship, at least they'd be albe to tell me whats wrong, charge me for their diagnostic work, and then I'd be able to fix the REAL problem. Anyhow, thanks for the insight guys....if ya'll have anymore suggesstions, they are always welcome. Thanks again! SmoothSteve Quote
GP1138 Posted June 14, 2004 Report Posted June 14, 2004 ICM, ICM, ICM! I was having the same problem, except my car actually stalled out at almost every intersection! Find a junkyard, or buy new. Replace the ICM and coilpacks! It's worth a try, it completely fixed my problem. Quote
SmoothSteve3 Posted June 14, 2004 Author Report Posted June 14, 2004 Well, to those of you that said ICM and/or coil packs, ya'll were right on! I just got the car back from the dealership....I paid them to run some diagnostics......and it came back that the ICM was screwing up when it gets hot, and the 1/4 coil pack is going/gone too. Thanks a lot you guys.....ya'll are awesome. Now..... Anybody know how to get to/replace the ICM on a 3.1 MPFI? SmoothSteve Quote
Gearhead43 Posted June 14, 2004 Report Posted June 14, 2004 It's down on the block... 2 10 mm bolts near the top and one 10mm toward the center at the bottom... You'll best bet is to remove the oil filter and the oil pressure sender unit in order to get to that lower center bolt. .. Cause its very easy to break off the Oil pressure sending unit. Then you can remove the ICM/Coil pak Assenbly. I would go ahead and purchase a new ICM and 3 coils. When replacing the coils, do em one at a time. So you do not cross wire your PLUG wires. Quote
Baddflash Posted June 14, 2004 Report Posted June 14, 2004 Glad you finally got it figured out and glad we could help ya a bit... Like Gearhead said replace all the coils cause it only takes one bad used piece to ruin a bunch of new parts, it may cost more now but it will be cheaper in the long run. It might be easiest to number all the plug wires that way you can pull them all off and change the whole assembly as one piece without the old coils/ICM in the way. Good luck! Quote
GP1138 Posted June 14, 2004 Report Posted June 14, 2004 Glad you finally got it figured out and glad we could help ya a bit... Like Gearhead said replace all the coils cause it only takes one bad used piece to ruin a bunch of new parts, it may cost more now but it will be cheaper in the long run. It might be easiest to number all the plug wires that way you can pull them all off and change the whole assembly as one piece without the old coils/ICM in the way. Good luck! Exactly how I did mine. Glad to help, even if I did just chime in at the last second. Quote
SmoothSteve3 Posted June 15, 2004 Author Report Posted June 15, 2004 Man.....I tell ya.......those ICM bolts SUCK ASS. I spent 5 hours today trying to remove them......and I only got 1 out of 3 off. I got the upper right one pretty easily (I think its actually a 13mm), but the lower center one is stuck, and neither my dad nor I can even loosen it.... Oh well, so goes life. Thanks again everyone! SmoothSteve Quote
Gearhead43 Posted June 15, 2004 Report Posted June 15, 2004 13mm?.. umm they must have switch between 10 and 13.. ok.. try using a 2"or 3" extension with a LONG HANDLE for leverage.. I used a 3/8" drive racket and slid the hollow jack handle over the racket handle to make it longer so more force and be applied to loosening it up... The extenison I used is what really broke the long black oil pressure sending unit off... Which is why I recommend removing it. It's 15 at AutopZone or 35 at NAPA to replace. Quote
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