backfiring through exhaust after rebuild???

shelby2 · 02-16-2001, 04:44 PM

here's the thing, i have long tube headers with true dual exhaust so there is no h-pipe. it does not do it all the time and sounds as though it is coming from the drivers side pipe. it usually happens at low rpm's mostly at part throttle. maybe i'll take a look at the exhaust and i was going to get new sensors anyway.

this is what i thought the problem is. i thought that since the car has only 2.79 gears that the popping was from pre-ignition (detonation) because the power range for the car does not happen until about 3000 rpm and i thought that the computer would advance the timing so much that the engine couldn't keep up and therefore detonate, but i don't know. i am also going to have a custom chip made for it to change the fuel curve.

i hope it is what you think it is being the exhaust. i do know that where the header collector meets the exhaust pipe is not a real good fit. i have the aluminum exhaust gaskets that have a lot of wear on them and probably doesn't seal right. i'll have to check into that as well.

thanks Dark Knight

------------------
shawn hill
1967 ford mustang coupe, red w/white stripes, hood scoop, front and rear spoiler, sefi and c4, trickflow intake, 70mm mac tb/egr, billet fpr, 24# inj, c&l maf, heavy duty c4 w/transgo shiftkit, flowtech longtubes w/turbo mufflers, t-rex inline pump, ported and polished E7TE heads w/1.94,1.60 valves, lunati 292 cam, harland sharp 1.6 rollers, conventional 8" with 2.79 gears (soon will be gone)

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02-16-2001, 04:44 PM	#4
shelby2 Registered Member Join Date: Nov 1999 Location: O Fallon, IL Posts: 87	here's the thing, i have long tube headers with true dual exhaust so there is no h-pipe. it does not do it all the time and sounds as though it is coming from the drivers side pipe. it usually happens at low rpm's mostly at part throttle. maybe i'll take a look at the exhaust and i was going to get new sensors anyway. this is what i thought the problem is. i thought that since the car has only 2.79 gears that the popping was from pre-ignition (detonation) because the power range for the car does not happen until about 3000 rpm and i thought that the computer would advance the timing so much that the engine couldn't keep up and therefore detonate, but i don't know. i am also going to have a custom chip made for it to change the fuel curve. i hope it is what you think it is being the exhaust. i do know that where the header collector meets the exhaust pipe is not a real good fit. i have the aluminum exhaust gaskets that have a lot of wear on them and probably doesn't seal right. i'll have to check into that as well. thanks Dark Knight ------------------ shawn hill 1967 ford mustang coupe, red w/white stripes, hood scoop, front and rear spoiler, sefi and c4, trickflow intake, 70mm mac tb/egr, billet fpr, 24# inj, c&l maf, heavy duty c4 w/transgo shiftkit, flowtech longtubes w/turbo mufflers, t-rex inline pump, ported and polished E7TE heads w/1.94,1.60 valves, lunati 292 cam, harland sharp 1.6 rollers, conventional 8" with 2.79 gears (soon will be gone)