Backfire after heads/cam/headers!
Backfire after heads/cam/headers! ok guys i checked timing and PTV clearance is good. I put in a 228R cam, TSP LT's O/R/Xpipe, LS6 intake, 6.0L truck coils(was told they'll work fine with the car) 243 Z06 heads. Anyway today was the first startup and it ran fine, oil pressure come up good, then it started a random loud Pop out the exhaust. it would idle fine, POP, idle fine, POP....POP idle fine then i'd shut it down. Put in brand new plugs AFTER everything else was installed(A/C Delco stock ones gapped a .060) and it has newer(about 3 months old) plugs wires. It's REALLY worrying me. It's not out the intake, it's FOR SURE out the exhaust. Any help or idea's is appreciated here guys. ~Cole~
well after i posted that last one i went out to do a restart and try to bring up the rpm's a little(2k at most) and the car purred like a kitten. No backfires or anything. Sounded BADASS with heads/cam/Open headers
One thing i realized is that the plug wires seem stretched and maybe a .5" to short so i went and got some 6.0L Truck plugs and they are 1.5" longer then the ones i had. I think it's just that one isn't seated fully. I will try in the morning with the plug wires and i think that'll take care of it. I'll pull the plugs too, you guys think they shouldn't be gapped at .060"? maybe like .055 or so? Thanks guys~Cole~
One thing i realized is that the plug wires seem stretched and maybe a .5" to short so i went and got some 6.0L Truck plugs and they are 1.5" longer then the ones i had. I think it's just that one isn't seated fully. I will try in the morning with the plug wires and i think that'll take care of it. I'll pull the plugs too, you guys think they shouldn't be gapped at .060"? maybe like .055 or so? Thanks guys~Cole~ the only ground that came off the back of the head on the drivers side was hooked back up. i will dig around back there and maybe i missed one but i swear there was only 1 wire. Maybe i'm wrong there though
I've been searching most of the night and can't find out how many grounds are on the back of my '98 head. it may be the problem.
I've been searching most of the night and can't find out how many grounds are on the back of my '98 head. it may be the problem. Last edited by Cole Train; Apr 4, 2008 at 01:25 AM.
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the only ground that came off the back of the head on the drivers side was hooked back up. i will dig around back there and maybe i missed one but i swear there was only 1 wire. Maybe i'm wrong there though I've been searching most of the night and can't find out how many grounds are on the back of my '98 head. it may be the problem.
I've been searching most of the night and can't find out how many grounds are on the back of my '98 head. it may be the problem.LS1 Tech Stories
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Brett Foote well after i posted that last one i went out to do a restart and try to bring up the rpm's a little(2k at most) and the car purred like a kitten. No backfires or anything. Sounded BADASS with heads/cam/Open headers One thing i realized is that the plug wires seem stretched and maybe a .5" to short so i went and got some 6.0L Truck plugs and they are 1.5" longer then the ones i had. I think it's just that one isn't seated fully. I will try in the morning with the plug wires and i think that'll take care of it. I'll pull the plugs too, you guys think they shouldn't be gapped at .060"? maybe like .055 or so? Thanks guys~Cole~
One thing i realized is that the plug wires seem stretched and maybe a .5" to short so i went and got some 6.0L Truck plugs and they are 1.5" longer then the ones i had. I think it's just that one isn't seated fully. I will try in the morning with the plug wires and i think that'll take care of it. I'll pull the plugs too, you guys think they shouldn't be gapped at .060"? maybe like .055 or so? Thanks guys~Cole~
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Joined: Sep 2005
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On a C5, you have to be careful to hook up your front O2 sensor wires to the correct sides. If you did not mark them when you took it apart, there's a very good change you crossed them when you put it back together, which will cause idle and drivability issues. Swap those two connections and see if it clears up.
oh you know i wonder if i did cross them thanks for that man Also i will double check the grounds and see if one is further back, Then i'll put on my new wires, regap the plugs and check the o2 wires and see where i'm at. Thanks SO much for the help guys.~Cole~
thanks for that man Also i will double check the grounds and see if one is further back, Then i'll put on my new wires, regap the plugs and check the o2 wires and see where i'm at. Thanks SO much for the help guys.~Cole~ Last edited by Cole Train; Apr 4, 2008 at 10:00 AM.
ok checked all grounds, they are fine, Check o2's and they were crossed but didn't fix the issue. Regapped plugs put on new wires STILL popping. So i hooked up my LS1m Palm scanner. and it was missing on #2 well i started to trouble shoot. Changed plug, wire, coil pack swap around, injector and it was still missing. so i pulled valve cover, rockers were fine. Then i start to fear the worst, bad compression but before that i started thinking about the coils i got for it. I remembered that the truck they came from blew up it's motor because one cylinder was dead and washing the walls. Well i remembered hearing it was #2. WTF are the odds. so i swap back in my old coils and harness and VIOLA, PURRS like a lion on steroids PEFRECT idle(minus the cam chop,lol), no misses, Not even a check engine light for anything. So i determined that it was the Coil pack harness. It's the ONLY thing that wasn't eliminated until i switched back the coil packs to the stockers. Thanks for ALL the help guys. I SO appreciate all the input. Although it turned out to be nothing serious it was still good to go over everything that could "likely" be the issue. even though it turned out to be nothing major at all. It COULD have been catastrophic~Cole~
P.S. if anybody is curious about the LS1m scanner, all you need is a Palm Pilot and an OBD2 ADAPTER for it. I'm not sure where to get the Adapter but here's the software for it on THIS site. http://ls1m.com/
but before that i started thinking about the coils i got for it. I remembered that the truck they came from blew up it's motor because one cylinder was dead and washing the walls. Well i remembered hearing it was #2. WTF are the odds. so i swap back in my old coils and harness and VIOLA, PURRS like a lion on steroids PEFRECT idle(minus the cam chop,lol), no misses, Not even a check engine light for anything. So i determined that it was the Coil pack harness. It's the ONLY thing that wasn't eliminated until i switched back the coil packs to the stockers. Thanks for ALL the help guys. I SO appreciate all the input. Although it turned out to be nothing serious it was still good to go over everything that could "likely" be the issue. even though it turned out to be nothing major at all. It COULD have been catastrophic~Cole~P.S. if anybody is curious about the LS1m scanner, all you need is a Palm Pilot and an OBD2 ADAPTER for it. I'm not sure where to get the Adapter but here's the software for it on THIS site. http://ls1m.com/
