LonestarHP

I have had this car set up the same way for about 25K miles and one afternoon about a month ago it just started running like crap. At idle it will pop thru the exhaust sometimes but between 2K-3K rpm's with mild to medium throttle it will be ok(or at least not very bad) for the most part but try giving it more throttle and it will start sputtering and popping thru the exhaust. I have changed the fuel filter and O2 sensors and cleaned the MAF. I am not really sure what else it could be. I was wondering if might be related to the valve springs because they are around the point I need be changing them, could this be the problem? Any help or advice is greatly appreciated.

King Nothing

iTrader: (9)

check your iac and clean that off . . . sputtering and poping is a vaccum leak

Grimes

iTrader: (3)

you try changing the plugs and wires yet?

Moscosoalfredo

My friend has the same problem with his lt1 and one of his rocker arms is loose.... and keeps on getting loose.... he is going to fix that soon.....

LonestarHP

Yes, I have changed the plugs & wires along with the other things that I mentioned. As for the IAC where is that located?

King Nothing

iTrader: (9)

look at your TB, there are 2 sensors on the drivers side and it's the top sensor. unplug it, take it off the tb clean it off then put it back in

LonestarHP

Thanks for he info. I will definitley try that and see what happens. Do you think it would have anything to do with the valve springs?

LonestarHP

I cleaned the IAC as King Nothing said but it still runs like crap!!!! Any other suggestions? Moscosoalfredo mentioned his friend had a problem with a rocker arm causing the same problem...could vavle springs cause the same problem????

King Nothing

iTrader: (9)

it doesn't sound like a problem in the valve area but i could be wrong . . . best of luck dude!

Relapse

iTrader: (4)

When i took my car out to the track one night, i ran it, and my spark plug wire came loose, over a course of a day or two, it started backfiring, sputtering like you're saying... i would check your wires again man, you could have one that went bad on you. That's just my 2 cents. Get it scanned also, see if the comp is throwing any codes. Mine gave off a cylinder misfire on 8

lil-bit

A buddy of mine has a ls1 with full bolt ons w/ cam. He was having a problem like your having and was scared to drive the car. but it was sounding like yours and it had white smoke coming out the pipes. when he took it to nelson performance they opened the motor and it was a stuck lifter. the lifer had broke and got stuck. it wasn't able to move up or down. so maybe have some one check that out. he wasn't racing or anything it just happened out of no where.

allblacksrt4

iTrader: (3)

check your pcv valve. mine was clogged burnt the tube and i had a huge vaccum leak and it did the same exact thing.