Need LS1 Serious help!!!
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I have a 99 slp ss auto car with a small cam and long tube headers! It was running great till about two weeks ago when a Cummings truck and i were messing around and at about 5000 rpm my car backfired (I mean like a cannon going off!) spit and sputtered and died to the point that I wasn't sure it hadn't blown up! Pulled to the shoulder of the road turned the key off and tried to crank it wondering what horrible noises I was going to hear! It cranked and ran fine??? My Ls1 guru in Waco and Nitro Dave from nitrous outlet are stumped!
David Clark from DC Motor sports has checked valves, springs, computer, fuel pressure (which dropped from 58 to 50 at one point) And Clark said that wasn't enough for it to do what its doing and not recover. And its not throwing codes?? Hes got the intake off now looking for cracks. ANY OTHER HELP WOULD BE APPRECIATED!
David Clark from DC Motor sports has checked valves, springs, computer, fuel pressure (which dropped from 58 to 50 at one point) And Clark said that wasn't enough for it to do what its doing and not recover. And its not throwing codes?? Hes got the intake off now looking for cracks. ANY OTHER HELP WOULD BE APPRECIATED!
#2
TECH Enthusiast
iTrader: (19)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
sounds like it misfired horribly. if it misfired then ide check the heads for sure then the bottom end, make sure you didnt crack the piston, bend the rod, or spin a bearing which is more worst case scenario. or maybe it detonated which is caused from a lean condition and again it would cause alot of the above also.
#5
The Scammer Hammer
iTrader: (49)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Like Taman86 said, sounds like a lean condition to me. Change your fuel filter.
When you take it off, immidiately cap the end of the old one with the plug from the new one and place it in a tub or tupperware; whatever you have.
Install your new one. Now, uncap the old one and start tapping it on the ground but INSIDE the tupperware. Tap like you're trying to get stuff out from the side where the fuel ENTERS. See how much black **** comes out. Mine was HORRIBLE to the point I had to eventually drop the tank and get the **** cleaned out. In the meantime, I changed my fuel filter every 1k miles. But I had the EXACT same problem as you.
What made me think fuel problem was I would put it in 5th going about 30 and then put the pedal on the floor and it would start bucking like it was getting fuel starved. (Plugged filter, injector, etc.)
Hope this helps.
When you take it off, immidiately cap the end of the old one with the plug from the new one and place it in a tub or tupperware; whatever you have.
Install your new one. Now, uncap the old one and start tapping it on the ground but INSIDE the tupperware. Tap like you're trying to get stuff out from the side where the fuel ENTERS. See how much black **** comes out. Mine was HORRIBLE to the point I had to eventually drop the tank and get the **** cleaned out. In the meantime, I changed my fuel filter every 1k miles. But I had the EXACT same problem as you.
What made me think fuel problem was I would put it in 5th going about 30 and then put the pedal on the floor and it would start bucking like it was getting fuel starved. (Plugged filter, injector, etc.)
Hope this helps.
#6
TECH Fanatic
iTrader: (35)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
What is the problem, the fact that it backfired, Or is it still backfiring,,Or is it just that your fuel pressure is low, or changing,,If it is the pressure problem, start with the filter and check like posted above, but if it persists Your regulator may be the culprit.