• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Car Randomly Dying... Well Kind of....

MaximusNeo701

New member
Ok I am new here and love this place. I usually just surf and look at all the awesome how to's.

EDIT: 1999 3.8l non supercharged. Grand Prix

History of the car: Bought it 4 years ago 97,000k miles. Replaced Harmonic balancer(trying to fix noise) had tune-up and PCV valve replacement(high pitch noise.) Followed suggested maintenance scheduel. After 2 years had transmission replaced with a used one, car had 126,000, replacement tranny had 70,000. I had no money and no real choice, tranny was DESTROYING itself cause the gasket went bad and went low on fluid. Apparently an issue before i got the car but got worse when i had it. Also had intake manifold rebuilt and upgraded to newest version. Tires, alignments, bearings,... etc. Stuff that is not really relavent to this I don't think. Also it has a K&N cone filter and new mufflers(shouldn't matter.)

Recent issue: Fuel pump making noise. replaced fuel filter, did not help. Followed guide posted here and replaced the pump myself. Actually the whole unit, cause its one peice. Worked fine already drove around 500 miles on it no problems and is very quiet.

Current Issue: I was driving down the road tonight. Car seemed to not have an HP or Tourqe. I push on the gas pedal and it kinda gave something but then quickly stopped. Car was coasting, i pushed the pedle and nothing happened, no power. The cars lights are on, the Tac shows the RPM's randomly jumping between 0-2000. Like the car is having an issue. If i pushed on the pedal it still would not give anymore power, but exhaust sound seemed to be muffled when i did it.
I turned off the stereo, tried pushing on pedal. Nothing. I put it in neutral, tried pushing on pedal and letting off and push. Eventually i got some power back. Then the car seemed to work find, put it back in drive and picked up from coasting. Scenario lasted maybe 45-60 seconds.
Driving down the road some more, turn stereo back on. Driving couple of minutes later issue started again, pushed on pedal couple of times. Nothing, turned off stereo and put in neutral. Pushed on pedals no reaction still. Starting going up a hill, then engine completely shut off 0RPM. Car is still on, lights etc. Actually the battery and oil light came on, like when you have the ignition on but the car is not running. I coasted and pulled over. Turned everything off. Turned key, almost started not long enough, turned again. Started just fine, the car drove like nothing happened. I did get pulled over later so i had the car off for like 10 mins. But other than that it drove me 15 more miles where i needed to be. But i need to fix it because i will be driving home from college in 2 weeks. 200 miles.
I also remember the couple of times i was in my car tonight before this, when i started the car it seemed to have an issue turning over. Sometimes took me 2 tries to start it. But i figured i did not try long enough (like 1-2 seconds) i just flipped it and let go (less than a seconds.)

I would appreciate any input or troubleshooting techniques. No check engine light so no error codes :(

Should i take it somewhere and what should i tell them to try and get help?
 


Maximus, from your description your problem sounds almost exactly like one I had with my last GP. When it happened to me though I did get trouble codes which helped. I replaced the throttle position sensor and the mass air flow at the same time as both showed issues, so I am not sure if it was one or the other or both which caused the main issue. The TPS is much less expensive though so that might be a nice starting point. It is hard to be too sure without a code to guide you but unless someone has any other insight this might be a good option.
 
Ok i can try that, The MAS is located on the intake i believe, but I don't know where the Throttle Body Position Sensor is located. Could you describe where I might find that?
 
Sounds like possibly a bad MAF. Your correct, the mass airflow sensor should be located just before or on the throttle body. Im not 100% sure on the 05 N/A engines. It shouldn't be too hard to find. You can diagnose that this is part of the problem by simply unplugging it. If there is no difference when it is unplugged, go ahead and replace it. When it is unplugged or bad, the pcm defaults back to a different table that is used in the event of a maf failure. It may have a rough idle and stall out at times.
 
The only issue i have with that plan is it has run before unhooked and seems to drive exactly the same. But no roughness or bad idle. I will check it though.
 
Back
Top