How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask MikeB85 Your Own Question
MikeB85, ASE Certified Technician
Category: Car
Satisfied Customers: 354
Experience:  ASE Certified, I-Car Trained and Certified, Automotive Technology Degree
Type Your Car Question Here...
MikeB85 is online now
A new question is answered every 9 seconds

2002 pontiac: 3.8..goes dead..already replaced..crank shaft..coolent

Customer Question

my 2002 pontiac grad prix gt 3.8 sometimes goes dead when hot after siting for 45 minutes will crank up already replaced crank shaft senser. gives code po128 which is coolent temp to low.whats causing it to go dead
Submitted: 9 years ago.
Category: Car
Expert:  MikeB85 replied 9 years ago.

When you mean dead, do you mean the car does not crank at all or does the vehicle crank and crank but just won't start? And this is the only code that has come up?

Let me know and I will see if we can get you fixed up. Thanks.

Customer: replied 9 years ago.
Reply to MikeB85's Post: it cranks but just want start for about 45 minutes, only does it about once a week, i changed fuel filter yesterday, begining to think its fuel related, havent checked fuel pressure yet.always happens at a place thats to noisy to hear fuel pump. when you crank the car it some tmes acts like it wants to start. most of the time its when you kill the car, go into a store and come back the car starts then it kind of sputters and dies like its not geting any gas or maybe flooding, ive pulled vacume line from fuel regulator, seems to be fine no gas smell. and as ive already said ive replaced fuel filter,crankshaft sensor, ignition moduel, thermostat, temp sending switch the one with three wires since it was giving trouble code po128.
Expert:  MikeB85 replied 9 years ago.

If you already replaced the ECT and the code is still coming up then there might be a possibility of a short in the circuit for the sensor. One thing that you can do if you have access to a scan tool is compare the ECT with intake air temperature. On a completely cool engine with a scan tool, the ECT should be within 3°C (5°F) of the IAT. If it isn't and the P0128 code is coming up then I would lean towards a short or an open in the ECT circuit. Like you mentioned above, I would also get that fuel pressure checked when the problem occurs and see what's going on there. Most likely since this seems intermittent, I would lean more towards something with the ECT circuit if that is the only code that is coming up. This could also be caused by a poor connection due to a connector being bad or this could be a bad connection at the PCM. I hope this helps. Please let me know if you have any other questions.

MikeB85 and 5 other Car Specialists are ready to help you
Customer: replied 9 years ago.
Reply to MikeB85's Post: i havent received the code po128 since i replaced the temp switch over a week ago, how ever it has went dead on me . i finally got it to die on me at home, i turned key to listen to fuel pump didnt hear anything, turned key again and heard pump it sounded bit slugest, done it a third time and on the fourth time i tried to crank the car and it started up, hasnt went dead since i replaced fuel filter, but that was only 2 days ago. i can get it checked at chey place for 75 dollars but im afraid that would be a waste of more money unless it would die on me there
Expert:  MikeB85 replied 9 years ago.
Something you can try yourself is checking for power at the pump when the problem occurs. If there is power to the harness at the pump then I would suspect a bad fuel pump. If there isn't then there could be an issue in the harness itself or wiring or possibly the fuel pump relay. Another thing you can try is switching the fuel pump relay with a known good relay to see if it does the trick. This however, is only if you don't have power to the fuel pump connector when the problem occurs. The fuel pump relay should be in the underhood fuse block. There should be a relay/fuse legend underneath the cover telling you which one it is. I hope this helps. Let me know if you have any other questions. Thanks.
Customer: replied 9 years ago.
went back dead today at home, fuel pump did not run but you could hear like a bump and click from fuel pump so sounds like its getting power at fuel pump, but fuel pump starts running after 45 minutes and car starts, is this a bad fuel pump is it geting hot and shuting off until it cools, would like your advice again before i spend 3 hundred on a fuel pump plus putting it in, again it only goes dead on me when i drive it a while shut it off and when its restarted it goes back dead