Backfiring upon decel

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Oct 29, 2004 | 06:17 AM

ButchN

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From: Dracut, MA

Backfiring upon decel

Ever since I had my LT's, ORY & exhaust installed, the car backfires, sometimes loudly upon decel whether the car is in gear or I toss it in neutral.

Here's the exhaust system.

Here's the only dyno chart that car has, & that's with the new exhaust & no LS1 edit tune.

I've also noticed there always seems to be moisture in my exhaust tips lately.
I don't know if that's due to the 50 degree days were having now.

The coolant level is right where it should be.

Does anyone have any suggestions as this is driving me crazy & I'm afraid one of these pops will ruin my exhaust valves or muffler or both.

Thanks.

Oct 29, 2004 | 06:55 AM

TAQuickness

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From: Houston

It's called raz. Raz is unburned fuel lighting off in the exhuast pipes. A lot of folks like it. If it's troubling you that much, you can probably remedy it by getting a tune, or just stick a quiet muffler on there.

Oct 29, 2004 | 07:43 AM

jermstyle

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From: Houston

yea, what pimp said... if you REALLY don't like it, get a better muffler.

Oct 29, 2004 | 09:12 AM

bletour2001

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From: Windham, NH

Quote:

Originally Posted by ButchN

I think a tune will help some as well. After I first put my LTs & GHLS on my Vette it would backfire loudly as well on decel. (From what I have been told the LS1 normally cuts spark almost instantly on decel leading to extra unburnt fuel) After tuning I still get the mellow pops and sometimes slightly louder snaps if I instantly let off at HIGH RPM (5000+) but NOTHING like it was before the tune. You can't make it totally go away (unless you put a quiet muffler on) but a tune can mellow it in my experience.

--Bill

Oct 31, 2004 | 03:58 PM

ButchN

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From: Dracut, MA

Quote:

Originally Posted by Pimp_Nas_T

Oh, it's not that.
I'm used that "burbling" & the Hooker I have is quite quiet, until you stomp on it.
It's this: http://home.comcast.net/~ta2000/dynoflame.wmv

But I found the cause of the problem.

The air pump bolts, both sides, collector bolts & band clamp from the ORY to the muffler were all loose.

Tightened it all up, no more tick, tick, tick, exhaust noise & no more backfires like what you saw in the video.

One air pump bolt on the driver side header was frozen.
I used PB blaster, it started moving, got it almost all the way out then snap!

Thanks for the assistance.

Oct 31, 2004 | 05:31 PM

bigdsz

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From: Mount Dora, Fla

I hope with your new exhaust system you are going to park your car for the winter. I'm from Florida, I didn't realize the damage that the salt does to the undercarriage of a car.

Oct 31, 2004 | 06:34 PM

_JB_

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From: Tampa, FL

Quote:

Originally Posted by bigdsz

I hope with your new exhaust system you are going to park your car for the winter. I'm from Florida, I didn't realize the damage that the salt does to the undercarriage of a car.

Yeah I hate living here in MI because of the snow/salt. We might be moving to Ocala sometime next year, so I'm looking foward to not having any snow lol.