Intermittent rough idle
Thread Starter
Racer
Joined: Oct 2005
Posts: 271
Likes: 0
From: Suisun City CA 1992 Coupe LT1 A4
Intermittent rough idle
I've got a 92 LT1 coupe with an automatic and I've been experiencing an intermittent rough idle and a spitting back through the exhaust. I thought it might be the spark plugs so I changed them and everything seemed fine for a few days and then the stumble would return then disappear again as quickly as it came. I then thought it might be some dirty injectors so I bought some injector cleaner and all was well for a week or 2 and it returned. It seems to run fine at freeway speed but when you slow back down to below 25 mph it would start to miss again and pop back thru the exhaust. When it is running well its smooth as silk and throws me back in the seat when I accelerate like a Corvette should. Could it be my oxygen sensors making the computer do something with the fuel mixture? I'm at a loss.
Melting Slicks
Joined: May 2005
Posts: 2,730
Likes: 1
From: Atoka Oklahoma
St. Jude Donor 06
mine was doing something of the same thing, except mine had rough idle at a stand still. mine ended up being the throtle body was dirty and i mean dirty. half a day of cleaning and my problem was fixed. just a thought. also no codes were thrown.
Burning Brakes
Joined: Aug 2005
Posts: 772
Likes: 6
From: Huntsville AL
How many miles are on your plug wires?
Either the plug wires or possibly the EGR valve acting up.
Since the EGR valve is such a pain to change I would start w/ new quality plug wires (Taylor, MSD or similar 8mm) if they have a fair amount of miles on them.
Either the plug wires or possibly the EGR valve acting up.
Since the EGR valve is such a pain to change I would start w/ new quality plug wires (Taylor, MSD or similar 8mm) if they have a fair amount of miles on them.
Thread Starter
Racer
Joined: Oct 2005
Posts: 271
Likes: 0
From: Suisun City CA 1992 Coupe LT1 A4
Actually the car has 70000 miles and had been stored in a garage for the last 3yrs by the previous owner, the wires are probably original. I've already changed the right side when I did the plugs but the left side is a bit more complicated. Would have done it but at the time it seemed to run so much better and I just didn't have the time to really get into it.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
I would go TBclean up before HT leads.Problems with leads show up under load , as in revs not at idle.
4 bolts and the TB is off.Sure to full of gunk.
Buy a can of TB cleaner and new gasket.
Take the TPS and IAC off and spray away.Will have to reset these on reassembly.
4 bolts and the TB is off.Sure to full of gunk.
Buy a can of TB cleaner and new gasket.
Take the TPS and IAC off and spray away.Will have to reset these on reassembly.
Thread Starter
Racer
Joined: Oct 2005
Posts: 271
Likes: 0
From: Suisun City CA 1992 Coupe LT1 A4
Thanks. I'll clean the throttle body first chance I get along with changing the plug wires on the left side. I haven't done any car repair for some time and I'm not familiar with some of the acronyms used such as TPS and IAC please pardon my ignorance.
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Melting Slicks
Joined: May 2005
Posts: 2,730
Likes: 1
From: Atoka Oklahoma
St. Jude Donor 06
Originally Posted by wrw7255
Thanks. I'll clean the throttle body first chance I get along with changing the plug wires on the left side. I haven't done any car repair for some time and I'm not familiar with some of the acronyms used such as TPS and IAC please pardon my ignorance.
after you get the books besure to have a digi cam at hand because we like to look a pics....
enjoy
