Low rpm missfire Options

[supra12big]

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So, i have this very low missfire/thump at around 1200 rpms, but if i play with the tps i can almost change the location of this missfire/thump, its very werid, and i believe it affects driving throughout the rpm range
Parts i have changed out.
Plugs
Wires
Cap+Rotor
Fuel Filter
TPS

anyone have any ideas/methods of testing things?

when the tps is disconnected it misses alot more

[mneal2_92788]

change teh O2

[supra12big]

o2 seems to be in check, goes into loop at idle, and open when driving, i don't believe its the o2

[supra12big]

anyone else got a clue? i did a boost leak down test, set timing..

[lagos]

what bov are you using?

have you tried...
1. setting your tps to its factory position?
2. changing your cap/rotor/wires/plugs?
3. a new coil?

[95celgt]

meh....check compression, bad ringland will cause this....did it to me anyway...

[supra12big]

tps is new, and is set to factory position, brand new spark plugs, and wires, cap and rotor have about 2k on them, waiting on a coil, the one that is in there did pass the test, compression is 180 across the boards, using a hks ssqv(has given me no problems)

also when driving and light throttle is applied/vac is between 20-10 it kinda bucks/thumps, but when i give it some more gas it seems to go away, but i believe myself that its the igintion, and i doubt its my ignitor since it doesn't follow in those symptoms, hopefully the coil will do it

I do pull off 21vac at idle, but when my car is around 2k on the dev rev it gets really low like 25-26 while it pops, lol

This post has been edited by supra12big: Jul 11, 2008 - 2:04 PM

[supra12big]

anyone????