Scrappy

Hey guys my car is backfiring for some reason? When I get into the gas hard. It bogs then backfires and then the power kicks in? Any ideas as to why. I have not done anything new to the car in over a year. The car is only driven on the nice weekends and this has never happened before. ANy ideas would be greatly appreciated. Scrappy

technical

I'm thinking either bad gas or bad O2 sensors.

~JOSHUA

iTrader: (92)

I'd start with the basics. Like technical said it might be bad gas. I've seen fuel filters crap out after only 7k miles ( my LT1 did that), plug wires. Whatever it is the computer is sensing something wrong. I'd start with a $10 fuel filter and a bottle of Lucas fuel injector cleaner.

superchannelkev

iTrader: (8)

my car ran like crap when i change the plugs, they didnt have any ngk's in stock and i wanted my car running.... autolites or something, ran like crap backfiring and after not even 100 miles i said screw it and changed the plugs with some ngk's and ran like a dream- just my personal experience with backfiring, hopefully its one of the above or plugs and nothing too bad.
-kevin

NickcZ28

iTrader: (9)

CHECK YOUR FUEL PRESSURE!! this happened to me and it was the fuel pump going out..

Scrappy

I got it scanned and it shows no codes the car has 33,000 miles. I filled up the tank and put some injector cleaner in it. It seems to be getting a little bit better but it still bogs around 4k rpms. I let it run in my garage last night and revved it a few times and I got alot of water out of the exhaust and the water has black.

Scrappy

UPDATE: OK I just got back from a ride and it is starting to have small backfires at idle. This is driving me batty I may be off to the dealership on Tuesday since it's still under warranty.

Dustin Butts

iTrader: (5)

Missed any shifts lately or had any 3rd gear to 2nd gear(instead of 4th) or 2nd to first(instead third) shifts lately? If so.. you may have bent some valves or PR's. No instrument panel SES lights? Could be a lot of simple things; however an SES light should be coming on.
Has the car had any computer tuning done that may have altered the misfire detection and thus restricted the SES light from coming on?

Scrappy

Nothing has been done to the car at all. The car has been sitting and I have had no missed shifts?

Dustin Butts

iTrader: (5)

It has been sitting and just all of a sudden started this behavior? How long does it usually sit? Any underhood evidence of mice chewing through wires? My car will get mice poop on the intake manifold during the winters if it sits too long. Trying putting fresh gas and a couple bottles of water remover that's safe for O2 sensors in the fuel tank.

Scrappy

It usually only gets driven about 3 times a month and it just started all of a sudden? There is no evidence of mice or anything like that? I am getting frustrated.

Dustin Butts

iTrader: (5)

Try the fresh gas/water removal deal. Maybe you got a bad batch of gas at your last fill up? You never said if you're getting a "Service Engine Soon" light or not...

Scrappy

I posted yesterday that my car is backfiring and seems to have a power loss. When I get on the gas hard it will stumble then backfire then take off like it should. I have checked my plugs and wires changed my fuel filter and put new gas and injector cleaner in it. I have no SES light and Autozone's computer found no codes stored. The car has 33,000 miles on it and is only driven about 3 or 4 times a month it has not been modded in over a year. When I revved it earlier I got a lot of black water out of the exhaust. Any help will be appreciated. Thanks in advance Scrappy

My Mods are SLP longtubes Y pipe high flow cats, loudmouth, intake, filter and bellows. Just incase it is pertinent.

01FbTaWs6

iTrader: (12)

first off, the water coming from the exhaust is just condensation, and it is black because of all the carbon buildup in an exhaust system, this is normal. Anyways, I would take it to the dealer, since you said it is still under warranty, get your moneys worth, and doesnt look like any of those mods would void the warranty, so have them take care of it

Dustin Butts

iTrader: (5)

Drive it around all day..take a road trip and burn all that gas out. By then you'll probably have an SES light if something's wrong. Check your O2 sensor wires...they're not laying on the headers anywhere are they? Burnt O2 sensor wires will do this but you should get a code...

1QuickT-A

iTrader: (12)

sounds like fuel or spark problems.. but check the 02 wires, maf sensor, etc..

LT1-Runner

Scrappy,
I am not sure that we are having the exact same problem but it seems to be very similar. My LT1 with K&N filter in-take has resently developed a rapid and repeated backfire problem every time I quickly put the throttle more than half-way down. My TA is a 95 with only 39,000 miles. I had the distributor, plugs and plug wire changes but the problem still exists. I have had two different shops perform computer diagnotics but nothing shows up on the computer. One of the shops was a local Pontiac dealer.

RedLT4Mike and I are talking on the "Backfire from intake?" thread

1999 SS

iTrader: (3)

im having the same problem but my car starts stumbling around three thousand rpm. i recently had a fuel pump (walbro 255) installed and the car runs rich (always has) and slightly backfires at a light. i figured the car needed fresh tuning but the shop that did the install went out of buisness.

LT1-Runner

Yeah, mine used to only have problems at 6,000 rpms and 45 - 60 mph during WOT. Now, I can't push it more than half way down before it starts popping/backfiring repeatedly. Don't know what to do? Seems I've seen a lot of sights where people are having the same problem but conclusive resolutions are rarely posted. Kind of sucks when my 92 Topaz with 145,000 miles has better acceleration than my 95 TA with 39,000.

TJ

iTrader: (10)

i have the same problem with mine, and its got a carburetor on it.
change the plugs and it goes away.
even with new plugs, if it idles a lil bit, ill have a break up/stumble when the motor is cold at about 3600 rpms.

it got so bad on a set of ngk tr55's, it would pop and die with more than 1/8 throttle.