LS7 backfires at idle?
#1
LS7 backfires at idle?
Hi guys,
I have stock crate LS7 with gmpp pcm. Headers and 3" pipes with short borlas.
After cold start, it bangs/backfires 5-10 times. Could it be too lean due high flow exhaust?
Any ideas?
I have stock crate LS7 with gmpp pcm. Headers and 3" pipes with short borlas.
After cold start, it bangs/backfires 5-10 times. Could it be too lean due high flow exhaust?
Any ideas?
#3
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Exhaust backfire or intake backfire? If exhaust, check for leaks
#5
If it does this during cold start then its in open loop, and not reading the 02's yet. So exhaust leak wouldnt matter at this point.
Does it have the same backfire after it warms up or after a hot start?
Its most likely a fuel supply issue causing it to run lean. Check your fuel pressure at the rail and see if its within spec.
Also make sure all sensors are plugged in including the MAF.
Last edited by Compsystems; 01-22-2017 at 03:42 PM.
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It would if its dumping fuel, sucking in fresh air, and then igniting the in burnt fuel.
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If it's intake backfiring I'd check your cool subharnesses for bent pins and possibly mismatched pinouts