Backfiring Engine!
Thread Starter
Intermediate
Joined: Dec 2001
Posts: 48
Likes: 0
From: Hamden Ct.
Backfiring Engine!
I have a 87 Vette with a 175K L-98. After not running the car most of the late summer and fall, I charged the battery to run some fuel stabilizer through the system to prepare for winter storage. The initial startup sounded hideous, then after warming up started to sound like a Vette engine again. Then came some awful backfiring and smoke. I had posted earlier in the year about minor backfiring and power loss, and was advised that I might have some excessive carbon buildup. I was told to carefully spray some water (mist) through the throttle body to dislodge carbon from the tops of the pistons. I have a MAF system and am a little skeptical about how to do this. The shortblock was dealer replaced at 140K, but I'm sure that the top end is stock, except for the injectors that look awful large. I could use some advice and a good mechanic in the Connecticut area. I have done a lot of things to my Vette on my own, but tearing into the engine is not within my comfort zone. Thanks in advance.
Tony Lopes :cool:
Tony Lopes :cool:
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
Re: Backfiring Engine! (87BLKVETTE)
it sounds like you have some screwed injectors... there may be 1 or more that are stuck open... gunked up from sitting.
I donno if the stablizer did that, or if just being idle did it...
I donno if the stablizer did that, or if just being idle did it...
Burning Brakes
Joined: Jul 2002
Posts: 871
Likes: 0
From: Costa Mesa CA
Re: Backfiring Engine! (87BLKVETTE)
Yeah....
When I installed my 52mm throttle-body (I have a lot of porting done as well), it back-fired like crazy from a dead stop. Then I read a tip here that setting the TPS at 7.2V-7.4V instead of 5.4V like the manual said, would richen the off-idle mixture. Did that and it was cured.
Back-firing is an indication of a lean mixture, among other things. Check for stored codes and proper initial timing.
Something to try.
BIG JIM
When I installed my 52mm throttle-body (I have a lot of porting done as well), it back-fired like crazy from a dead stop. Then I read a tip here that setting the TPS at 7.2V-7.4V instead of 5.4V like the manual said, would richen the off-idle mixture. Did that and it was cured.
Back-firing is an indication of a lean mixture, among other things. Check for stored codes and proper initial timing.
Something to try.
BIG JIM
