1992 Pontiac Grand Am 92 Grand Am won't start when air temp

Tiny
HARWICH
  • MEMBER
  • 1992 PONTIAC GRAND AM
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 150,000 MILES
1992 grand am 2.3 quad 4 with single OHC. In the morning when the air is cool the car will start up and run but later in the day when it has warmed up it cranks but never starts. After you try to start it you can smell the gas (hood up, air filter off). I have recently replaced the coil housing and the O2 sensor. When it starts it runs well but it does run rich. Any help will be greatly appreciated.
Wednesday, June 11th, 2008 AT 8:39 PM

13 Replies

Tiny
MASTERTECHTIM
  • MECHANIC
  • 4,750 POSTS
How about a leaking fuel pressure regulator. Check the vacuum hose to the regulator and see if there is any signs of fuel in it, if there is then thats your problem. The regulator will bleed the raw fuel directly into engine when its off causing it to flood. Let me know
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Thursday, June 12th, 2008 AT 3:58 PM
Tiny
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I checked the vacuum line off of the fuel pressure regulator and there is no evidence of gas in the vacuum line. In fact until recently the vacuum line was not even hooked up. I just noticed about a week ago that there was a loose line and where it went. The behaviour is the exact same with or without the vacuum line on the regulator.

Thanks
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Friday, June 13th, 2008 AT 6:10 PM
Tiny
MASTERTECHTIM
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Can you acess a fuel pressure gauge and check pressure and also check for leak down like maybe a leaking injector? Also when she wont start can you check to see if there is spark? You will have to remove the coil housing and install plug wire jumpers but you could be losing spark when it has a hot soak due to a bad crank sensor. Very v ery common. Only about 20 bucks and one bolt holding her in.
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Friday, June 13th, 2008 AT 7:16 PM
Tiny
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Sorry for the long delaly I have not had time to work on this until recently.

I do not have access to a fuel pressure guage.
I went a head and replaced the crank position sensor. I also had to replace the neutral safety switch because it was going bad. The crank sensor did not make a difference. I am going to try to check for spark this evening. This may be a stupid question but do you just use a standard set of plug wires as jumpers from the coil housing? If so do I need to find some that have a straight boot at both ends?

Thank You
Steve
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Friday, August 1st, 2008 AT 7:53 AM
Tiny
MASTERTECHTIM
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Any kind of plug wire that will hook onto it
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Friday, August 1st, 2008 AT 6:05 PM
Tiny
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  • 8 POSTS
OK, I pulled off the cover with the coil housing and removed one plug to use for testing. I connected the spark plug wire to the tower on the coil housing and connected the other end to my test spark plug. I laid the spark plug on a motor mount to ground the outside of it and had someone crank the engine. When they first started cranking it I got a couple sparks and then nothing. I moved the wire to all four of the towers and tried it again and got no spark on any of them. I even put a screwdriver in the plug wire and positioned it right next to the metal motor mount and got no spark. I have already replaced the coil housing, the spark plugs and the crank sensor so I am thinking the problem is probably the coils or the ECM. What do you think?

Thank You
Steve
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Saturday, August 2nd, 2008 AT 8:09 AM
Tiny
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I replaced both coils and had the ICM tested by a parts store. They said the ICM was good. Still no spark.
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Saturday, August 2nd, 2008 AT 12:29 PM
Tiny
MASTERTECHTIM
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A shorted coil can cause this to happen. Everything else you already replaced. Double check the plug at the crank sensor and make sure the individual connectors are tight and also check the plug on the coil cover plug.
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Saturday, August 2nd, 2008 AT 5:33 PM
Tiny
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I am not sure what you mean by a shorted coil. I just replaced both of the coils. I did also check the voltage into the ICM per the Haynes manual. I will double check the other connections.
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Saturday, August 2nd, 2008 AT 6:40 PM
Tiny
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I checked all the connection and even pulled the crank sensor out cleaned it and re-installed it and still no spark. What do you think the chances are that the ICM is bad despite testing ok? That is the only part of the ignition system I have not replace. I am out of ideas.
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Saturday, August 2nd, 2008 AT 9:00 PM
Tiny
MASTERTECHTIM
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By a shorted coil I mean if the internal resistance is too low it will short out ignition module and result in no spark, but you already replaced them. A ignition module is what I would replace for sure. I was questioning how they would test a ignition module out of the car accurately, anyway I would definitely install a module, its the only logical thing left. These are pretty cut and dry, its either a crank sensor or a module. Especially where the problem was originally heat related. Let me know
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Sunday, August 3rd, 2008 AT 6:15 AM
Tiny
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It was the ICM. I even put the old coils back in and it starts and runs. Thanks for all of your help. I had never thought of using regular spark plug wires to test for spark in one of the coil on top systems.
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Sunday, August 3rd, 2008 AT 1:20 PM
Tiny
MASTERTECHTIM
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Cool. I never trusted the parts guys who say they can test icm's it just doesnt make sense.
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Sunday, August 3rd, 2008 AT 5:21 PM

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