Almost backfiring
Thread Starter
Instructor
Joined: Jan 2002
Posts: 227
Likes: 0
From: CA
Almost backfiring
When I rev the engine in Park I can hear a popping sound coming from the exhaust, almost as if the car is trying to backfire. I just replaced the rear Y pipe and mufflers today because there were 2 rust holes on the old Y pipe. Is there now a problem with the catalytic converter or something else. Any ideas why I am getting that backfire noise? Thanx.
Thread Starter
Instructor
Joined: Jan 2002
Posts: 227
Likes: 0
From: CA
Re: Almost backfiring (65Z01)
I'm not to car savvy yet so I dont exactly know how to check the TPS. Is that something I can do on my own or would I need a shop to do it? If it wouldnt be to difficult on my own could you direct me to a site or post that describes how to do it? Thanx.
Pro
Joined: Oct 2002
Posts: 586
Likes: 0
From: Schmuckville SA
Re: Almost backfiring (C490Vette)
It should be in the tech tip section...
You'll have to know your way around a voltmeter to set it right.
One question though, did it do this before the work was done?
You'll have to know your way around a voltmeter to set it right.
One question though, did it do this before the work was done?
Pro
Joined: Oct 2002
Posts: 586
Likes: 0
From: Schmuckville SA
Re: Almost backfiring (C490Vette)
At the least, you should have a general idea of what you have to do here.
It's one of the easier things to do on a Vette but if you are not sure, you
might have to take it to a shop. Problem with that is, it may be set ok as
well as your base timing. Does it do it hot and cold? And how bad is it?
There's no one in your area that can help you with that? Seeing it's a
90, more than likely wear and tear is culprit here.. Sticky valves?
Maybe they need adjusting? Could be...Mine does it cold if you
rev it over 3g.... I am not worried about it because it doesnt do it
hot and its a high milage motor.. I dont expect it to be perfect...
It's one of the easier things to do on a Vette but if you are not sure, you
might have to take it to a shop. Problem with that is, it may be set ok as
well as your base timing. Does it do it hot and cold? And how bad is it?
There's no one in your area that can help you with that? Seeing it's a
90, more than likely wear and tear is culprit here.. Sticky valves?
Maybe they need adjusting? Could be...Mine does it cold if you
rev it over 3g.... I am not worried about it because it doesnt do it
hot and its a high milage motor.. I dont expect it to be perfect...
Thread Starter
Instructor
Joined: Jan 2002
Posts: 227
Likes: 0
From: CA
Re: Almost backfiring (Unriced)
I don't belive it does it when it is hot. I havent really checked it yet though. It really isnt that bad, it only seems to be when the car is not moving and the engine is reved and not while I am driving, and it only does it while the engine is coming down from high rpms. I really dont hear it if I push the rpms up to 3000 and hold it there. The vavle covers were recently removed to replace the gaskets and I was told the valves were in good condition. I am gonna be taking a good 2 hour cruise tomorrow, so I will check it again tomorrow. Thanx for any help.
Burning Brakes
Joined: Nov 2000
Posts: 1,117
Likes: 0
From: DFW TX
Re: Almost backfiring (C490Vette)
and it only does it while the engine is coming down from high rpms. I really dont hear it if I push the rpms up to 3000 and hold it there. .
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