toon67 Posted July 26, 2012 Report Share Posted July 26, 2012 Hi I have a few question that i would like to ask..I have a 94 grand prix se,now when the car is cold it will run like it is suppose to.idle fines drives fine,but once it gets warm it will run like crap.rough idle stalls(sometimes)bogs down when you give it gas.has a hard time picking up speed.now if you let up off the gas and baby it seems to help some what.I am at a lost here with this.Things i have replaced so far. EGR plugs..wires MAP sensor IAC TPS Fuel Filter I do not see any vac leaks anywhere so i really have no clue to what it might be.Now the ignition switch did go out of it so i just installed a push button start on it.dont know if that has anything to do with it. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 26, 2012 Report Share Posted July 26, 2012 Checked the coilpacks and ICM? The way I usually do this is to get a coil pack from the junkyard and remove one pack at a time and see if it cures the issue. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted July 26, 2012 Report Share Posted July 26, 2012 x2 on the coils. I have a Buick Park Avenue that was having similar issues. I was getting Knock Retard, detonation, and a misfire when I gave it anything over about quarter throttle. Being OBDII, I was able (with the help of a good friend) discover that my misfire was on cylinders 3 and 6. They both run off the same coil pack, so I swapped it with a spare that I have, and it fixed the problem. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 26, 2012 Author Report Share Posted July 26, 2012 (edited) How can i find out which pack is bad?It will not show any codes when a scan tool is hookup to it. Check engine light does not even come on. Edited July 26, 2012 by toon67 Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 26, 2012 Report Share Posted July 26, 2012 How can i find out which pack is bad?It will not show any codes when a scan tool is hookup to it. Check engine light does not even come on. Just replace them one at a time with the good one - if the car is running well, you've fixed the issue. If not, move it to the next spot. These won't set off a SES light. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 26, 2012 Author Report Share Posted July 26, 2012 Yep it seems to be the coils on it..changed a few ran good,but i also think it has a bad ICM on it.going to wait till the morning and hit the junkyard and get a few. Thanks guys Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 28, 2012 Report Share Posted July 28, 2012 already fixed it huh? just like all the other fixes already done to it? blame the coil packs.. they run good with 11 through 15 volts just the same right? looks like your options are datalog it as it stalls and make educated guess as you review it or either that keep guessing and hit the ac on a hot day. that will stress the system and you will know. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 28, 2012 Author Report Share Posted July 28, 2012 Nope never fixed it.right back to running like crap.Taking it to the scarp yard on monday..I am done with it. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 28, 2012 Report Share Posted July 28, 2012 I fixed mine with a white shirt on and drove it down the street with the r-12 on max Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 28, 2012 Report Share Posted July 28, 2012 Nope never fixed it.right back to running like crap.Taking it to the scarp yard on monday..I am done with it. Yeah, it's way easier to scrap it than to diagnose it properly. Also easier to throw a bunch of parts at the problem instead of diagnosing it properly. My guess would have been a defective engine coolant temp sensor...but it'd be easy to prove or dis-prove that with a SCAN TOOL. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 30, 2012 Author Report Share Posted July 30, 2012 I really don't want to junk this car.It was my dads and this is one of the things he left me when he died.Everybody says....scan it with a scan tool to see what's wrong with it.Like i have not done that like a dozen times already.It will not show any codes at all.Yes and i did unplug the engine coolant temp sensor,and the fans came on,which was funny because i had to use a toggle switch to get these to come on before. I just wish i knew for sure what was wrong with it.Runs rough and bogs down when giving it gas.I am at a lost,but i do know one thing.after having this much trouble with this car and not knowing much about cars,i have been looking into going to school for car repair.I don't want to have to pay someone else tons of money to fix something that i think is so simple on this car.It fires right up everytime you go to start it.so i know it isnt something major. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 30, 2012 Report Share Posted July 30, 2012 ohm the injectors and see if there is a few bad ones. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 30, 2012 Author Report Share Posted July 30, 2012 I just read that this car uses OBD 1 right?The guy that used the scan tool was doing it as OBD 2..I remember him say when he plugged it in...He siad yep OBD 2 when it showed it on the screen of the scan tool. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 30, 2012 Report Share Posted July 30, 2012 copied from wiki ~1994: Motivated by a desire for a state-wide emissions testing program, the CARB issues the OBD-II specification and mandates that it be adopted for all cars sold in California starting in model year 1996 (see CCR Title 13 Section 1968.1 and 40 CFR Part 86 Section 86.094). The DTCs and connector suggested by the SAE are incorporated into this specification. 1996: The OBD-II specification is made mandatory for all cars sold in the United States. Quote Link to comment Share on other sites More sharing options...
tornado_735 Posted July 30, 2012 Report Share Posted July 30, 2012 You're down in Courthouse? Shit, I was just in Mt. Sterling yesterday. I would gladly have come and had a look at it for you. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 30, 2012 Report Share Posted July 30, 2012 Everybody says....scan it with a scan tool to see what's wrong with it.Like i have not done that like a dozen times already.It will not show any codes at all. Are you using a SCAN TOOL, or some piece-of-junk consumer-grade code reader? A code reader is NOT a SCAN TOOL, and is practically worthless. If you get NO data, the tool you're using isn't communicating with the ECM. Could be a failed ECM, could be wiring problems between the connector and the ECM, Could be a defective interface device--scan tool or code reader. Could be a MIS-PROGRAMMED interface device. Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 30, 2012 Author Report Share Posted July 30, 2012 Ok first off i know nothing really about cars just what i read online.So here it goes..If i spray throttle body cleaner into the air intake tube when the car is running it will run fine.I can give it gas and it won't bog down or anything,but once i stop spraying the cleaner the car will go back to bogging down when giving it gas.So could that be a bad fuel pump,or a fuel pump going bad?I have no way of testing the fuel pressure so just really taking a guess here. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 30, 2012 Report Share Posted July 30, 2012 you could ohm the injectors and see if they are all within a couple tenths. you could also get a datalogging cable and just download tunerpro RT v.5. just to monitor the sensors and crap. it will also tell you if your voltages are low. most likely they are. could be a bad battery or bad grounds. the cables are sold in the group buy section on the forums here for cheaper than anywhere else on the web. Quote Link to comment Share on other sites More sharing options...
ManicMechanic Posted July 30, 2012 Report Share Posted July 30, 2012 Are you using a SCAN TOOL, or some piece-of-junk consumer-grade code reader? A code reader is NOT a SCAN TOOL, and is practically worthless. If you get NO data, the tool you're using isn't communicating with the ECM. Could be a failed ECM, could be wiring problems between the connector and the ECM, Could be a defective interface device--scan tool or code reader. Could be a MIS-PROGRAMMED interface device. Being a 1994, it will be OBD 1.5. Wish I still lived in the Dayton area, I have the tools to diagnose. But I haven't lived there in 10 years. Quote Link to comment Share on other sites More sharing options...
Schurkey Posted July 30, 2012 Report Share Posted July 30, 2012 Ok first off i know nothing really about cars just what i read online.So here it goes..If i spray throttle body cleaner into the air intake tube when the car is running it will run fine.I can give it gas and it won't bog down or anything,but once i stop spraying the cleaner the car will go back to bogging down when giving it gas.So could that be a bad fuel pump,or a fuel pump going bad?I have no way of testing the fuel pressure so just really taking a guess here. Now we're getting somewhere. Engine is not getting enough fuel. You seem to have diagnosed that much. I'm betting you can quit looking at the spark plugs, plug wires, ignition coils and module. Surprising that the ECM isn't throwing a SES light, and storing a code. Very suspicious. There are multiple reasons for the engine not getting enough fuel, starting with the fuel filter being plugged, (except you've already replaced the filter) the fuel pump being defective, computer/sensor/wiring issues, defective injectors, and air leaks into the intake tract. How old is the O2 sensor? I had a pickup with a defective O2 sensor that tested good at any speed under 40 mph, but would turn on the SES light and drive the computer to full-rich at highway speed. Replacing the "supposedly good" sensor immediately cured the SES light. Quote Link to comment Share on other sites More sharing options...
Garrett Powered Posted July 30, 2012 Report Share Posted July 30, 2012 if you had an actual wideband then you would be able to rule out some stuff. just spray down the old one with some carb cleaner and put it back in. or throw another one in and see if it runs any different. hopefully a junkyard one for testing, if you are playing the throw parts at it game. an air leak into the intake would make it idle higher not bog down. throttle follower tuned improperly would make voltage drop too low and stress the whole car and everything electrical on it. including the fuel pump. I never pay any attention to codes thrown. pretty much useless with obd1 Quote Link to comment Share on other sites More sharing options...
toon67 Posted July 31, 2012 Author Report Share Posted July 31, 2012 Well it looks like this time i really found the problem on this car. [h=1]Manifold Air Temperature Sensor[/h] Unplugged it and away she went.no rough idle,no bogging down when giving it gas or anything.I hope this is the real deal this time.This is one sensor i have always overlooked thinking it could not cause the problem. Quote Link to comment Share on other sites More sharing options...
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