Mike96z

iTrader: (78)

Alright, dont think this is normal lol. But Im not sure what to check for exactly. The car will start fine, but most the time when starting Ill get a couple of loud backfires or pops before it starts then when moving it (not during idle) it will pop some more. Anyone think this is mechanical (timing chain gone bad?) or electrical (maybe needs a tune, degree adjustment?). Any input would be great, just wanted to see what you guys think, trying to catch up with my LS1 stuff, if it was an LT1 id know for sure. Thanks

car is 98 - Open headers

98REDZ

iTrader: (3)

good question im trying to polish up on my new daily driver A4 SS, poppin/backfiring under a slight load at 45mph, slight hesitation while idling thats barely noticeable and a shuttering hesitation through the RPM band while goin through the gears

6THZ28

iTrader: (11)

i would definitely start check the plugs and wires

Mike96z

iTrader: (78)

new plugs and wires. TR55's

Mike96z

iTrader: (78)

it pops really loud while trying to start, it takes most of the time 2 trys for it to start. Im just wondering if maybe its the chain. Whats the normal cycle for an LS1 timing chain? this motor has a little over 100k. new plugs and wires. Mods as listed in sig.

BADBOYZ28

iTrader: (228)

Mine did similar things and it was the crank sensor!

will350wax

iTrader: (21)

How does it run? only problems on idel and startup. or problems across the board.

Mike96z

iTrader: (78)

it has problems at start up and never pops during idle, but when i moved it the other day, when moving under load giving it gas it popped a couple times. so maybe it could be a crank sensor?

6THZ28

iTrader: (11)

I'm real curious what's causing the backfire.. And that was a good question about the stock timing chain. How long do they generally last? I'm about to change mine when I get my cam but still....

3.4camaro

iTrader: (1)

backfiring under load is textbook ignition problem. New plugs and wires should be in your future.

Klive

iTrader: (4)

dead plug or plugs...

daniel6718

iTrader: (36)

shoulda bought my pullout...sounds like a timing issue to me...cps cps or tune or cam installed wrong or timing chain or rockers adjusted wrong or wrong pushrods or open headers

chrysler kid

iTrader: (14)

your running open headers? like no manifolds at all? your not getting any backpressure so your gonna have all sorts of issues with the car not reading whats coming out of the exhaust and sucking in cold air backinto thehead and causing the car to backfire. put some manifolds and a ypipe on there first and thenlet us know if its still backfiring all the time

A-Bomb

iTrader: (27)

what did you gap your plugs to? when i put my car back to stock i over gapped the plugs and it was backfiring like crazy. i pulled them out and re-gapped and that fixed the problem.

Mike96z

iTrader: (78)

sorry id still pass on your pullout, its not that your parts are bad or anything, its just i got a really good deal from Lethal Performance, its not that big of a deal really, just wanna know whats causing.

for the rest, again, new plugs and new wires, correct plugs and gap at that.

as for OPEN headers that does not mean no manifolds, it means headers and nothing after the header so its not sucking air back into the head and that wont be it either. as listed in the sig, Hooker Super Comp LT's.

thanks for all the input, if someone has had a similar issue then maybe they could let me know. I have an idea as to what it may be, either timing chain issue or maybe the timing needs to be adjusted in the pcm. other than that the crank sensor.

another thing is that when I wired the car up, I wired both sides of the ignition to one ignition fuse, which is how the LT1 is wired up, havent figured out how to get it to work on 2 fuses as the LS1 is actually suppose to be wired, 1 fuse per 4 cylinders. that could be an issue, maybe not enough power because its all coming from one fuse and may be firing too slow or not firing enough and leaving extra fuel in the cylinder to be burned on the next ignition stroke causing a loud pop. just some things to think about i guess.

as far as the motor and assembly its fine. I actually got it from Lethal Performance in San Antonio

98 SS Engine

whitehooptie

iTrader: (2)

The LT1 car I have has 2 fuses for the injectors. Check for corrosion on the coil terminals, where the plug wire actually plugs in to. Make sure there is no green nastiness in there.

mariojmoe

iTrader: (14)

Mine is back-firing only when I'm coming off of a hard launch or when rpm's coming down Lemme tell you it's so damn annoying too.

10SecDreamer

iTrader: (7)

If your timing is all correct, check what your o2s are reading, might be running a lil lean from a vacuum leak somewhere.

will350wax

iTrader: (21)

well part of your problem is open headers. your 02s arent reading for **** at idel cause your headers are sucking cold air back in. put some exhaust on that thing.

Mike96z

iTrader: (78)

There is a big difference in the wiring of a 94 vs 96.