93 Grand Prix Posted March 6, 2003 Report Share Posted March 6, 2003 My GP is on it's death bed! I have asked for help, but nobody knows what is wrong. I have had this problem for a 1 1/2 years now, so I guess I better give up on her, because she is gonna give up on me. I don't know what else to do. All these problems are causing me to hate old cars. 1. engine hard to start when cold 2. engine lopes while idling 3. engine idles erratically 4. engine misses at idle 5. excessive fuel consumption 6. cooling fans won't come on 7. bad fuel odor 8. no power in 4th gear I have already replaced multiple things on this car. 1. Coils 2. Coil module 3. Spark Plugs 4. Wires 5. Coolant temp. Sensor (twice) 6. relays 7. water pump 8. oxygen sensor 9. cleaned throttle body intake 10. pcv valve 11. ECM 12. plenium gasket 13. 2 cans of carb. cleaner looking for leaks 14. tranny fluid flushed 15. EGR valve 16. IAC motor 17. lots of time and money Any other ideas what it could be? Listen to what I am talking about! Go to http://www.geocities.com/bigmamma93gp/index2 and click on the Pontiac Emblems. And maybe you can get a better idea of what I am talking about. Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 My GP is on it's death bed! I have asked for help, but nobody knows what is wrong. I have already replaced multiple things on this car. 1. Coils 2. Coil module 3. Spark Plugs 4. Wires 5. Coolant temp. Sensor (twice) 6. relays 7. water pump 8. oxygen sensor 9. cleaned throttle body intake 10. pcv valve 11. ECM 12. plenium gasket 13. 2 cans of carb. cleaner looking for leaks 14. tranny fluid flushed 15. EGR valve 16. IAC motor 17. lots of time and money Was able to listen to one of you .wav files (first one) before the bandwidth went ka-put on me. Was this all in the last year? Months? What do we have for a time frame? Something is got to be overlooked, with all those parts you've replaced, the car should be on top of its game! Have you had it looked at by a professional, and have the ECM downloaded to get a read out? From the sounds of it, it's lagging pretty bad due to fuel related (perhaps a rich mixture / like a choke is on), but since I'm not there... I can only speculate. Do you have a manual? Have you followed the trouble-shooting guide-lines? Sorry to hear about your troubles. - RedFox340 Quote Link to comment Share on other sites More sharing options...
93 Grand Prix Posted March 6, 2003 Author Report Share Posted March 6, 2003 I have had the ECM scanned and it says that everything is wrong, but it is throwing no codes! Any other ideas? P.S I have taken it to many professionals, and they have charged me professional prices! Quote Link to comment Share on other sites More sharing options...
patgizz Posted March 6, 2003 Report Share Posted March 6, 2003 old car? hehehe. Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 I have had the ECM scanned and it says that everything is wrong, but it is throwing no codes! Any other ideas? P.S I have taken it to many professionals, and they have charged me professional prices! Everything huh? Seriously, what were the results? If it's that big a problem, then junk it, if you can't give us valuable information then we can help you... I've never had a 2.8L / 3.1L that's gone to crap on me when the repairs are not without my reach. Maybe you can sell it to another 16 year-old who doesn't know any better... 11 years for me, and still chugging aways since day one! - RedFox340 Quote Link to comment Share on other sites More sharing options...
93 Grand Prix Posted March 6, 2003 Author Report Share Posted March 6, 2003 someone said that it could be an intake manifold leak? Is that possible? How do I check that? Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 12. plenium gasket someone said that it could be an intake manifold leak? Is that possible? How do I check that? Was this only the plenum? If so, the suggestion could help the situtation but won't fix it completely; especially if not codes are thrown. The car sounds like it's missing hard perhaps due to an extremely off air/fuel mixture, like the car is running rich and wanting to "flood" itself. Anything nasty comming out of the tail-pipe? Excessive carbon build-up or smoke? Possible fuel leak / purge? You did say you could smell gas... where? when? Again, need explicit details. - RedFox340 Quote Link to comment Share on other sites More sharing options...
93 Grand Prix Posted March 6, 2003 Author Report Share Posted March 6, 2003 I could usually smell gass when I start it up early in the morning. Seems to go away when it gets warm, or it is not as strong. i think that you are on the right track about the air/fuel ratio. Could the computer be causing this? I had it replaced. Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 I could usually smell gass when I start it up early in the morning. Seems to go away when it gets warm, or it is not as strong. i think that you are on the right track about the air/fuel ratio. Could the computer be causing this? I had it replaced. Is it from the same year with the same MEMCAL chip? Any warranty on it by chance? When was that installed and where? - RedFox340 Quote Link to comment Share on other sites More sharing options...
93 Grand Prix Posted March 6, 2003 Author Report Share Posted March 6, 2003 I am not sure what year the car was from, but the numbers matched on both the ECM and PROM/Mem-cal. I heard that I was supposed to keep the one from my car is that true? Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 Yeah, that's highly recommended... - RedFox340 Quote Link to comment Share on other sites More sharing options...
GrandPrix34 Posted March 6, 2003 Report Share Posted March 6, 2003 TIMING BELT!!! those are the symptoms my aunts car had...it was throwing a shit load of gas, it misfired like a muther, the exhaust smell WHFEEW...they changed her computer, crank position sensor, fuel pump/regulator, spark plugs and wires, etc. and no mechanic could fix it....well, one brave mechanic decided that is was a big enough challenge that he did not want to go by so he went all out....and lo and behold it was the timing belt... by the way, it was a beretta, 94 if im not mistaken.... Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted March 6, 2003 Report Share Posted March 6, 2003 TIMING BELT!!! That's a good point, but 93 Grand Prix: aren't you running a 3.1L? So a timing chain may be needed... - RedFox340 Quote Link to comment Share on other sites More sharing options...
anewall Posted March 7, 2003 Report Share Posted March 7, 2003 Don't forget to check the Fuel Pressure Regulator Valve!!! I have a '91 GP with a 3.1 and that's what I've been dealing with. It has had all of the same symptoms and I've replaced almost all of the parts you have. There is raw fuel in the throttle body that leaks down into the air filter. I traced the problem to the left most black plastic tube on top of the throttle body. This tube was running to the Regulator Valve which is under the intake plenum and connects the fuel rails. Apparently, the valve is stuck and letting raw fuel into the intake rather than fuel vapor, which chokes the engine making it stall and stumble and the gas mileage drop. I used the "check engine" light to read the codes it says all systems go, and I brought it to a garage who said they couldn't find anything with a scantool either. The Valve is about $100 new from Autozone, but just about free from the junk yard, especially since it can fit in a good sized pocket Just one more thing to try... Quote Link to comment Share on other sites More sharing options...
JS91Z34 Posted March 8, 2003 Report Share Posted March 8, 2003 I would check the plugs and see if you have alot of carbon on one or more of them. If you do, check the fuel pressure regulator vac. hose to see if there are signs of fuel, or take the hose off and plug it. start it and see fuel comes out the top of the regulator, if not move to the injectors to see if one or more might be stuck open Quote Link to comment Share on other sites More sharing options...
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