car missing poping under load
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From: ringgold,ga
car missing poping under load i recently swapped my hooker shorty headers and y-pipe to hooker long tubes, after that the car pops through the exhaust when reving it up to 2500-3000 rpms. misses under hard excellaration,and has losed power completely a couple of times. ive changed to denso o2s. even swapped computers,iac.,map censor,coil and module,plugs and wires. plugs before looked fine. car isnt smoking or running rich. on a friends computer it read 02 temps around 450, but didnt change much when the car was reved up. i switched to denso's since but havent had it back on the computer yet. knock sensor was also not picking up a signal. ive changed it and doesnt cut the check eng. light on with the other comp. volts to the knock sensor should read 0.0 with switch on and 2.5 with switch on. it actually reads 0.7 with switch off and 4.8 with switch on. anyone have any ideas??also headers are not coated.
If you are saying that the front O2s are reading 450mv (not temp), then you may have plugged the front O2s into the rear sensor harness - any chance you got them switched up?
You probably cracked some spark plugs.
edit: well I don't know what you mean by lost power completely.
Maybe you have a broken or loose ground wire, or you damaged one of the wires going to the starter.
edit: well I don't know what you mean by lost power completely.
Maybe you have a broken or loose ground wire, or you damaged one of the wires going to the starter.
You do want to verify "live" O2 sensors, they should bounce
like mad at idle / cruise and not show a steady voltage (that
being a sign of some electrical fault, on an LS1; you'd have to
research what an LT1 does).
If the headers greatly improved cylinder filling and peak pre-
spark pressure, you might need to decrease plug gap to get
rid of arc start problems. But also check ignition parts & wires'
integrity because failure to fire in the hole, means the spark
is looking for another way out. How is Mr. OptiSpark feeling
lately? Wires all clean and quiet, no visible arcing at night
with the motor loaded up? Do you have any means to look
for misfires etc. on the road?
like mad at idle / cruise and not show a steady voltage (that
being a sign of some electrical fault, on an LS1; you'd have to
research what an LT1 does).
If the headers greatly improved cylinder filling and peak pre-
spark pressure, you might need to decrease plug gap to get
rid of arc start problems. But also check ignition parts & wires'
integrity because failure to fire in the hole, means the spark
is looking for another way out. How is Mr. OptiSpark feeling
lately? Wires all clean and quiet, no visible arcing at night
with the motor loaded up? Do you have any means to look
for misfires etc. on the road?
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Thread Starter
9 Second Club
Joined: Jan 2006
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From: ringgold,ga
tried another pcm with no effect. opti is a possibility but its only has about 5k on it. and i didnt have any problems before the header swap. ive also changed plugwires and had no luck.
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9 Second Club
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From: ringgold,ga
(update) checked alternator and found that it isnt charging, atleast part of the time. will convert it to a L98 style(4.5lbs. lighter) tommorrow. this is the third alternator in three years. autozone reman. junk. dont know if this will fix the other problems but it has to be adressed.
