towlie
04-19-2012, 06:24 PM
Okay so ive been trying to figure this out for several months but cant solve it.
motor is blacktop s13 sr, runs awesome most of the time. minor bolt ons (FMIC, intake, 3" turbo back, etc) and stock boost at .5bar.
every now and then (maybe once every few weeks) it will start to bog and fall flat on its face.
the other day i was cruising on the freeway and after about 35 minutes of normal driving, it started cutting out. revs dropped to about 2300 (5th gear, cruising at 60-65) and would not make power. I was still hitting full boost (.5) and throttle was pretty deep. didnt want to make revs for shit, and my afr's were dead on 12.0 (no fluctuation, like it idle it will bounce around from 13.7 to 14.3 for example). came to idle and it was showing low 13's.. managed to limp to work crusing in low rpm's, ran fine as n/a, until hitting boost. try to do a pull and it would not build revs, just bogging horribly.
the thing that really boggles my mind is after i clocked off work (10 hours later), i fired it up and drove home, ran FINE. boosting normally, afr's were decent (tad lean)
ive noticed it only does this on a warm motor, and after parking it for several hours it will run fine (ie, bogs driving home in the pm, runs fine the next morning)
inspected maf, looks fine, on my next day off ill fully remove it and inspect wiring and everything. checked intercooler piping for cracks/leaks, no ripped couplers, no loose clamps, so im pretty sure its not a boost leak. Evreryone says its probably a boost leak, but if it was why would it come and go? running a sohc maf, z32 fuel filter, walbro 255, stock injectors.
also on occasion with a cold start it will choke at first boost, cut out maybe once or twice, and then take off as normal. ignored this, figured it was just a hiccup due to cold motor.
any ideas? im going to try replacing the FPR with a new OEM (or Nismo) and the cold temp sensor and see what happens. this is stumping me because of how it runs fine for weeks and then it will randomly bog, then run fine the next day. :confused:
motor is blacktop s13 sr, runs awesome most of the time. minor bolt ons (FMIC, intake, 3" turbo back, etc) and stock boost at .5bar.
every now and then (maybe once every few weeks) it will start to bog and fall flat on its face.
the other day i was cruising on the freeway and after about 35 minutes of normal driving, it started cutting out. revs dropped to about 2300 (5th gear, cruising at 60-65) and would not make power. I was still hitting full boost (.5) and throttle was pretty deep. didnt want to make revs for shit, and my afr's were dead on 12.0 (no fluctuation, like it idle it will bounce around from 13.7 to 14.3 for example). came to idle and it was showing low 13's.. managed to limp to work crusing in low rpm's, ran fine as n/a, until hitting boost. try to do a pull and it would not build revs, just bogging horribly.
the thing that really boggles my mind is after i clocked off work (10 hours later), i fired it up and drove home, ran FINE. boosting normally, afr's were decent (tad lean)
ive noticed it only does this on a warm motor, and after parking it for several hours it will run fine (ie, bogs driving home in the pm, runs fine the next morning)
inspected maf, looks fine, on my next day off ill fully remove it and inspect wiring and everything. checked intercooler piping for cracks/leaks, no ripped couplers, no loose clamps, so im pretty sure its not a boost leak. Evreryone says its probably a boost leak, but if it was why would it come and go? running a sohc maf, z32 fuel filter, walbro 255, stock injectors.
also on occasion with a cold start it will choke at first boost, cut out maybe once or twice, and then take off as normal. ignored this, figured it was just a hiccup due to cold motor.
any ideas? im going to try replacing the FPR with a new OEM (or Nismo) and the cold temp sensor and see what happens. this is stumping me because of how it runs fine for weeks and then it will randomly bog, then run fine the next day. :confused: