dbtk2 Posted January 30, 2005 Report Share Posted January 30, 2005 Ok, so since about October or so, my dads TGP has started running worse and worse everyday. It used to just kinda miss a little, but just at WOT. It has gotten worse and worse, and its starting to get to the point where you can't really drive it. At WOT the car will sputter, kick, miss, and sometimes backfire, and it doesn't accelerate very fast like this. Obviously this is not good, but I can't figure out WTF is wrong with it. Basically, I'm down to coils or fuel pump, but I'm not sure which. I've replaced the fuel filter, plugs, wires, and 02 sensor (it needed them all anyways). Before throwing a bunch of money into it just to have it not fix the problem, I figured I would ask here and see if anyone has an opinion on whether it is coils or fuel pump or maybe something I didn't think of, possibly injectors? I tried to put the coils off my STE on it, but I couldn't get to the bottom bolt on the module so I could only get the 1,4 coil off, and replacing that one didn't make a difference. Any ideas? Shawn Quote Link to comment Share on other sites More sharing options...
Gearhead43 Posted January 30, 2005 Report Share Posted January 30, 2005 I tried to put the coils off my STE on it, but I couldn't get to the bottom bolt on the module so I could only get the 1,4 coil off, and replacing that one didn't make a difference. Take off the oil filter and the oil sending unit, you'll be able to get thAT CENTER BOTTOM BOLT. Good time to change the oil while you are at it.. Take the coil and check for low resistance. Then take the ICM to AutoZone and have them run about 4 tests on it.. it'll have to pass 4 times.. ..It will get hot during 4 tests .. so you'll know it wont fail after it gets warmed up... USE GM coils... if you replace any. You can also get an adjustable spark plug tester from Autozone. It can detect weak coils that still fire. Giving you a false indication that all coils are working has they should be. A weak coil can still fire, but it will misfire under load. Quote Link to comment Share on other sites More sharing options...
90TGP Posted January 30, 2005 Report Share Posted January 30, 2005 Sounds like what happened to my car when the fuel pump kicked the bucket. Quote Link to comment Share on other sites More sharing options...
gp90se Posted January 30, 2005 Report Share Posted January 30, 2005 $30 autozone fuel pressure gauge, doesnt hurt 2 have 1 around Quote Link to comment Share on other sites More sharing options...
Bossman429 Posted January 30, 2005 Report Share Posted January 30, 2005 I'm gonna go with my usual response to these and say.....Ignition Control Module, but that's if all the coils are ok. Have AutoZone test the ICM. If you wanted to be sure it's not the fuel pump you can get a fuel pressure gauge and tape it to the windshield so you can see it when you're at WOT. That's what we do at work. I can't remember what fuel pressure is supposed to be, but I think it's somewhere around 40psi usually. Quote Link to comment Share on other sites More sharing options...
Gearhead43 Posted January 30, 2005 Report Share Posted January 30, 2005 YUp a good fuel pump will maintain 40 PSI fuel line pressure. AutoZone sells a fuel pressure test guage that attaches to the S valve at the fuel rail. Quote Link to comment Share on other sites More sharing options...
futuretgper Posted January 30, 2005 Report Share Posted January 30, 2005 sounds sorta like what mine did when i first got it...turned out to be bad injectors....does it have a hard time starting after it warms up....or run worse after it runs for awhile?? how well does it just idle? Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted January 31, 2005 Author Report Share Posted January 31, 2005 I have a fuel pressure guage that connects to the rail, it just requires me to remove the schrader valve in the rail for it to work, and I don't have anything to remove it with. I'll probably bring the car into school and use one of our fuel pressure gauges. The car got an oil change last week so I don't really need to pull the filter off, but I guess it won't hurt. I'll try again to get that module off, because I do think thats probably the problem. Thanks for the suggestions, I'll try a couple things and let you know what I find. Shawn Quote Link to comment Share on other sites More sharing options...
perfecseal Posted January 31, 2005 Report Share Posted January 31, 2005 I had the same problome with my 91 cavalier z24. 3.1 5speed .. I replaced every sensore injector and pump .. In the end I pulled the timing cover and found that it had jumped time.. just a thought If nothing works.. Quote Link to comment Share on other sites More sharing options...
idbeast Posted February 3, 2005 Report Share Posted February 3, 2005 YUp a good fuel pump will maintain 40 PSI fuel line pressure. AutoZone sells a fuel pressure test guage that attaches to the S valve at the fuel rail. On a TGP you need 40-45 PSI at Idle, 55-60 at WOT. (that is why the TGP uses a different fuel pump then the other W-Bodys) Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 9, 2005 Author Report Share Posted February 9, 2005 Well we replaced the ICM and all the coils (afterall the car does have over 130k on it and it still had the factory coils and ICM) and it is definately not any better. So that means it has new: Plugs Wires 02 Sensor Coils ICM It is gradually running worse and worse and worse, and it has a hard time starting all the time really. Sometimes it will fire right up, other times you have to try 10+ times to get it to start. Once it starts it idles normal (as normal as it ever does with the stock crossover) but if you get on the gas at all, it runs like crap. Would injectors cause this? My dad says he thinks its the ECM, but that wouldn't be getting gradually worse I wouldn't think...it seems like it wouldn't run at all if that was bad. Opinions please...I'm stumped. I think it has plenty of fuel pressure, I haven't got a chance to hook up a gauge to it yet, but it took like 30 seconds to release all the pressure from the rail when I pressed the schrader valve. How do you know if it has bad injectors...high fuel pressure??? Would hooking up a Tech 1 tell me anything if the injectors are functioning improperly? Thanks, Shawn Quote Link to comment Share on other sites More sharing options...
idbeast Posted February 9, 2005 Report Share Posted February 9, 2005 Opinions please...I'm stumped. I think it has plenty of fuel pressure, I haven't got a chance to hook up a gauge to it yet, but it took like 30 seconds to release all the pressure from the rail when I pressed the schrader valve. How do you know if it has bad injectors...high fuel pressure??? Would hooking up a Tech 1 tell me anything if the injectors are functioning improperly? Thanks, Shawn If you don't want to pay attention, don't ask for opinions. :shock: 1. Get a fuel pressure gauge and find out if has the proper pressure. 2. if the pressure is in specs replace the injectors. 3. AFTER you done step 1 and if needed do step 2 then come back and ask for help, but don't waste peoples time if you are to cheap or lazy to try to get it fixed. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 9, 2005 Author Report Share Posted February 9, 2005 If you don't want to pay attention, don't ask for opinions. :shock: 1. Get a fuel pressure gauge and find out if has the proper pressure. 2. if the pressure is in specs replace the injectors. 3. AFTER you done step 1 and if needed do step 2 then come back and ask for help, but don't waste peoples time if you are to cheap or lazy to try to get it fixed. I am paying attention to what people are saying, and I am going to check the fuel system, but I also wanted to let people know that I replaced the coils and ICM now to give them other possible ideas on what might be wrong. I also wanted to know how to tell if the injectors are bad by testing fuel pressure, if you even can. I know this will test the fuel pump, but does this tell me anything about the injectors? You just said yourself if the pressure is normal then replace the injectors. But I'm not sure the problem is even with the fuel, so it doesn't make any sense to spend $100's more on replacing even more parts that don't need to be replaced. Things like coils, ICM, plugs, wires, fuel filter, 02 sensor, and stuff like that (everything we've replaced) is okay because its basically normal maintenance stuff anyways and it was all fairly old. I am going to check the fuel pressure the next time I get the chance, but its not my car so its not like I can work on it anytime. It has to be when he isn't using it and I'm not busy, which is usually only about 1 night a week, if it was my car I would've already done a fuel pressure test on it. I appreciate all the opinions so far, and I'm listening to them, and I'm going to test the fuel pressure, but I just wanted to see if anyone had more opinions. Shawn Quote Link to comment Share on other sites More sharing options...
idbeast Posted February 9, 2005 Report Share Posted February 9, 2005 You can do an OHM check on the injectors, do a search on both w-body and Waskies TGP board for the detailed instrutions on how to do it. My comments were made because, knowlegeable people (several of them on this board) have left good ideas, but if you have 30lbs of fuel pressure it will idle but not run any rpms or pull a load. you need to find out what the fuel pressure is to give people a chance to help you fix this. To often is is a basic simple thing that someone thinks is OK so they don't check it. I've got 4 of these cars (used to be 5) and I've turned wrenchs on all of them, I've even found a few problem that only 2 other people have had so if it comes down to it I'll explain these hard to locate problems, but I won't get ino it except to say it is a wiring harness issue. If you think it is a ECM issue swap the one out of your TSTE and see if it works right. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted February 27, 2005 Author Report Share Posted February 27, 2005 Figured out what the problem was. Did a fuel pressure test, 18psi fuel pressure, obviously nowhere near enough. Its getting a fuel pump Tuesday. Shawn Quote Link to comment Share on other sites More sharing options...
TurboGTU Posted February 27, 2005 Report Share Posted February 27, 2005 so how many votes went to fuel pressure. Good to finally find the colprit. 8) Quote Link to comment Share on other sites More sharing options...
richiewwhite Posted April 21, 2005 Report Share Posted April 21, 2005 Post up on how the fuel pump went? if it had fixed the problem. Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted April 23, 2005 Author Report Share Posted April 23, 2005 Wow this is kinda old. The fuel pump defiantely fixed the problem. I don't know what I can really post about it...a new one was installed and now it runs right...what else can I say? Shawn Quote Link to comment Share on other sites More sharing options...
Jeff M Posted April 23, 2005 Report Share Posted April 23, 2005 Wow this is kinda old. The fuel pump defiantely fixed the problem. I don't know what I can really post about it...a new one was installed and now it runs right...what else can I say? Shawn Uhhh, that you found the fix and what the fix was Other people like to know what the end results were, specially if they lent a hand and offered some ideas on what it might be, or like these guys, looking for why their car is not running right and what might fix it 8) Jeff M Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted April 23, 2005 Report Share Posted April 23, 2005 Well, I am adding to this post cause I am having simalar issues as he is, just not to the extreme he was. Under light acceleration the motor kinda hickups, if I lean into the gas some more, it clears out. At wide open throttle, it doesnt really reach it and you can physically feel the motor falling off. Last night it backfired thru the intake. If I maintain about 3/4 throttle, it has no problems, and still accelerates really hard. So far I have replaced the wires and plugs with OEM stuff. I am ordering a O2 sensor, oil lines, x-over from Jeff M next week. And I am going to put on a new ACDelco Coil pack and ICM Tuesday. All my local part stores are out of stock on the fuel pressure guage, so I have to wait for someone to get it in. The car starts perfectly, with no extended starting, and idles really smooth. My fuel milage is a little low at 14.9 MPG. I am not getting any check engine lights. Thoughts and ideas on this one other than what I have mentioned? Quote Link to comment Share on other sites More sharing options...
dbtk2 Posted April 24, 2005 Author Report Share Posted April 24, 2005 That is basically what this car would do. If it was cold sometimes it would be hard to start, but warm it was better for some reason. But it would backfire through the intake and hesitate when you got on the gas and if you went WOT it would definately not run right. New fuel pump and it runs like it did before. Shawn Quote Link to comment Share on other sites More sharing options...
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