misfire/hesitation
Jul 19, 2006, 12:56 PM
#1
misfire/hesitation
ok, last week i did a ebay O2 housing and a unorthodox underdrive setup (crank, water pump, and alt.) after i did this i took it for a ride the first 15 min i didn't get on it at all, to make sure everything was good. i put gas in it and since then it hasn't run right. at first i thought it was bad gas so i put in some isopropl dry-gas and a bottle of 104+ octane boost (black bottle). there has been 2 tanks through it since then and it still is doing the same thing. it feels like a misfire and it hesitates when it does, this only happens between 15-22psi. i changed the plugs (bpr8es gap to .020 it was .022) that didnt help, checked for boost leak, there are none. could it be that the underdrive pulleys have started to make the motor knock. i've heard that sometimes they do weird stuff. do you think i should leave the pulley on there and see if they and tune it for the pulley.
ps: i did reset the ecu both after the mods and also when it searted to act funny, no cel as of yet.
mods: TTR flash, buschur 3"TB, turbo XS intake, mbc, greddy bov, ebay O2 housing, home made ground kit. tuesday next week going to Turbo trix for a EcuTek tune.
ps: i did reset the ecu both after the mods and also when it searted to act funny, no cel as of yet.
mods: TTR flash, buschur 3"TB, turbo XS intake, mbc, greddy bov, ebay O2 housing, home made ground kit. tuesday next week going to Turbo trix for a EcuTek tune.
Last edited by BURNALL_4; Jul 19, 2006 at 01:57 PM.
Jul 19, 2006, 01:16 PM
#3
Try putting the stock crank pulley back on. The underdriving pulleys often don't dampen out the vibrations properly and can cause abnormal vibrations (which could also lead to crankshaft failure, which is why no one uses these things). Also, the belts rubbing on the new pulleys may be generating a new frequency of noise which is being picked up by the knock sensor as detonation. This is far fetched but it would be worth swapping back to stock just to see if it helps. Good luck!
