Weird misfire down low \=
08-21-2008, 11:37 AM
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Weird misfire down low \= My car has had this problem for a while, and I've changed numerous things thinking I'll figure it out. Anywho, I recently got the car running after a heads swap, and for some reason (randomly) the car will backfire through the intake if I quickly give it throttle to accelerate faster. If I ease on the the throttle it's fine. This typically happens at a low RPM, usually when accelerating from a stop or if I'm traveling at a low RPM.. It's so weird. I've changed the coil, icm, opti, wires, plugs (are only 3 weeks old), injectors, car throws no codes, etc. I'm pretty stumped. Any ideas? 
08-21-2008, 03:28 PM
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Cam wasn't changed and car rean great before
Nah, it's a stupid ignition problem that I can't trace. )=
my cousins TPI firebird did that for a while, on a brand new motor
turned out there was a 1/4 inch long chunk of the headgasket missing inbetween two cylinders. looked like someone cut it out with a razor blade? but the gaskets were brand new so?
not saying thats what it is, but you never know
turned out there was a 1/4 inch long chunk of the headgasket missing inbetween two cylinders. looked like someone cut it out with a razor blade? but the gaskets were brand new so?
not saying thats what it is, but you never know
08-21-2008, 10:07 PM
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Sounds quite similar to my problem, unsolved as of yet. Was run on dyno and ignition scope, the shop found nothing, though they could not get it to miss on that day.
Just because you think it's ignition related, doesn't mean it is, don't paint yourself into a corner, you'll have less likely of a chance of figuring it out.
Just because you think it's ignition related, doesn't mean it is, don't paint yourself into a corner, you'll have less likely of a chance of figuring it out.
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08-21-2008, 11:39 PM
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Would probably sound something like a hammer hitting the block
08-21-2008, 11:47 PM
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Not like a hammer lol, but it's a loud *** tick. Very loud. I don't see how this would cause a low RPM backfire through the intake, and at high RPMs run fine
08-21-2008, 11:57 PM
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Its going to have to be REAL bad for something like that to happen, but your right that would be near impossible if it clears up at high RPM.
Got something laying around to check your fuel pressure? Would be a good time to verify how that pump is working...
Got something laying around to check your fuel pressure? Would be a good time to verify how that pump is working...
08-22-2008, 11:52 AM
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A reman, but it ran the same before with a GM unit. It actually runs a bit better with this new Reman once but the low rpm backfriew through the intake is still there, and inly happens when i quickly tap the gas to accelerate quick
