Backfiring? What the @#$@?

wahoo50

Member
Joined
Sep 4, 2002
Car has been running great, no recent changes, but now when accelerating hard it will backfire loudly under the hood. At night you can see what looks like fire coming from the air intake. Ideas anyone?
 
You're giving us about as little info as possible to help you, what about some data specs, the age of parts, trouble codes, plug gap etc?

Is your timing at least 20 degrees + when the alky turns on?
 
Backfire

I have FAST and had a similar prob just recently.My car backfired vilently under boost, got worse when it got hot.Had a bad ground for comp, the factory grounds at the head and intake, chased it for 2 weeks. hope it helps.
 
This car has been running great, nothing new has been added in the last year. Don't have any trouble codes or data specs to offer.

Drove it approx. 200 miles today, as I neared home I started off from a red light, got up to 15 MPH in low gear, floored it, just as the tires began spinning it hit about 4,000 rpm and boom, I backed off, shifted to drive, drove a ways down the road, slowed to try again, and again, same thing, boom, I backed off and drove home.

SeeyaV6 - are you saying check the ground for the computer?
 
Backfire as it hits high boost is often a symptom of a failing/weak coil pack..... or a 'lean pop', which is worse... :eek: I would 1st verify fuel pressure is rising 1:1 with boost, and if so, probably start at the coil pack....
 
I agree with the "lean pop".
I've had this issue twice (also running FAST), both times was a failing alky pump, replaced pump and problem fixed.
HTH
 
All ideas seem good. I will now go to work through process of elimination. Thanks so much for the imput.
 
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