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1992 Pontiac Grand Am

Tiny
WALTERJII
  • MEMBER
  • 1992 PONTIAC GRAND AM
1992 Pontiac Grand Am 4 cyl

Cylinder 3 is not firing. Already checked fuel injectors. Yet when in passing gear, it seems to operate normally. Changed plugs, no improvement. Next step is to see if plus is actually firing. Do you have any other thoughts.

Many Thanks
Walter
updated 1/24/09
Originally, last week, I asked the question about a 1992 GrandAm with a cylinder not firing. Mechanic responded that I should check the coil pack which I
did. I now believe I have an intake valve stuck open. How do I check for sure. Compression test, maybe?
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Wednesday, January 21st, 2009 AT 12:26 AM

6 Replies

Tiny
RACEFAN966
  • MECHANIC
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Make sure you check the coil boot. If it looks bad then get new coil boots and replace them. Look for any signs of burning or cracks and also look for any carbon tracking on the coil pack the coil pack housing maybe allowing the spark to get to ground before getting to the plug. Let me know what you find.
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Thursday, January 22nd, 2009 AT 10:31 AM
Tiny
RACEFAN966
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Do as I have instructed and let me know what you find.
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Saturday, January 24th, 2009 AT 8:53 PM
Tiny
WALTERJII
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As I have previously indicated, I replaced the coil pack and no change, cylinder still does not fire. Checked spark on that cylinder, appears to be ok; Only thing I can think of is a stuck open intake valve. Would the next step be a compression test.
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Saturday, January 24th, 2009 AT 9:44 PM
Tiny
RACEFAN966
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Ok check compression in that cylinder and see what it is. It could still be an injector not firing so that we will check next. Let me know what the compression is so we can rule that out. After that we will check the number 3 cyl. Injector ok. Get back to me.
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Monday, January 26th, 2009 AT 3:39 PM
Tiny
WALTERJII
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As I have previously stated, I check the injector, cleaned all injectors and switched injector on problem cylinder, check spark to that cylinder, everything was OK, yet when I disconnect current to the injector, engine runs the same, so that cylinder is not firing. Next step will be to do a compression test if I can find a proper gage.

When I do that I will contact you. This is a good example of just how much at risk a vehicle with fuel injection can place a person in when things go wrong. Can not be repaired on the spot like a non-fuel injection vehicle can. Need to think about finding a vehicle that will be dependable in the bush.

What surprises me is that when at high rpm like when passing, the engine seems quite normal, like that cylinder kicks in.

Thanks for the help.

Walter
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Monday, January 26th, 2009 AT 6:05 PM
Tiny
RACEFAN966
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Well that can happen as the rpm increased you are less likely to feel it if it is a bad injector. If you need to get a noid light that fits you car (GM Type) and do a noid light test to make sure the pulse is there as it should be. If you need anything else just ask.
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Tuesday, January 27th, 2009 AT 10:10 AM

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