Ok so gonna list my mods first. Apexi intake, cooleze pipe, tms downpipe, blitz nur spec no cat, 2.5 inch aluminum ic piping w/ stock intercooler, stock ct-26, walbro 255, mhg etc nothin else important. Anyways i put on my 2.50 inch ic piping kit cause it came in today, and now im hitting fuel cut @ 8 psi. It only happens when it shifts (automatic) but i think it may be shifting just because its hitting fuel cut and taking a load off the engine so it shifts. Any advice would be nice. Oh also, the turbo started making a funky ass whining noise after i put the ic piping on. The couplers are all tight and connected good, and i dont have any vac leaks. Im thinking bad turbo, since the whine. Also the old IC piping (stock ic pipes that have been on for 160k miles) have oil/gunk in them. The headgasket blew about 15k miles ago and was fixed but i never cleaned the stock ic piping.
Hitting fuel cut... Help?
- Thread starter Fubar231
- Start date
I'd still check to make sure that you have no leaks with a boost leak detector just to be 100% sure.
I would guess boost leak. It's seems too coincidental that your turbo would go bad right after replacing IC piping. With a boost leak you will hit fuel cut at a lower reading on your gauge because air is leaking out, but the turbo still has to push all of that air through.
the turbo is wat flows more air not the piping. smaller piping= less lag bigger piping = more lag cause theres more space to fill with air.
check for boost leaks and check for shaft play on the turbo.
check for boost leaks and check for shaft play on the turbo.
I think i may have found the leak, i dont have an air compressor so i cant do a boost leak test myself, but i think i found the leak. The pipe that runs above the 3000 pipe, its the one closest to the firewall, one of the 2 rubber things was like halfway out. Long story short, i think i found the leak and its real close to the throttle body so that may... have had some effect. I havn't fixed it yet, (going to later or tomorrow), but i got a lead!
whining noise is the turbo spinning at higher revs, you have a boost leak.. same pressure more rpm on the turbo, hits boost cut earlier etc is exactly the issue, are you sure your intercooler is still ok?
from what i can tell it doesn't cut fuel, just ignition. and its not dependant on boost levels, it depends on load, afm reading, knock counts, temp etc.
i find mine hit boost cut on a hard shift into 2nd gear.. at around 3-4 psi. but would be fine up to round 9psi.
my monies still on boost cut, go keep looking. could be your intake manifold even (where it joins to the head)
you can get some carby cleaner spray and spray round the manifold joins or close to the throttle (too far away and it wont work), if the rpm increase as you spray you have a leak,
from what i can tell it doesn't cut fuel, just ignition. and its not dependant on boost levels, it depends on load, afm reading, knock counts, temp etc.
i find mine hit boost cut on a hard shift into 2nd gear.. at around 3-4 psi. but would be fine up to round 9psi.
my monies still on boost cut, go keep looking. could be your intake manifold even (where it joins to the head)
you can get some carby cleaner spray and spray round the manifold joins or close to the throttle (too far away and it wont work), if the rpm increase as you spray you have a leak,
^^
I was starting to think its the intake manifold gaskets, but before i got around to finding it, BOOM coolant leak. What coolant lines run under the intake manifold? I can see it dripping onto the steering rack and around there... Im thinking iscv hose from the bottom? I need to go get a floor jack tomorrow and get under there. Ill let you guys know.
I was starting to think its the intake manifold gaskets, but before i got around to finding it, BOOM coolant leak. What coolant lines run under the intake manifold? I can see it dripping onto the steering rack and around there... Im thinking iscv hose from the bottom? I need to go get a floor jack tomorrow and get under there. Ill let you guys know.
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=CO&P=2
I promise the TSRM will answer most questions
I promise the TSRM will answer most questions
When I had a boost leak, as it got worse, the bypass valve got quieter and quieter until you couldnt hear it.
So i think its my bottom ISCV hose. Im going to get new clamps on it first before i replace it cause i cant get the hose off with the intake manifold still on so clamps first then well go from there. Coolant leak more important than vac, i also think my intake mani gaskets are going bad.
paradox616;1368162 said:
Just happened to see this...it's way wrong.
Fuel cut in fact does exactly that...if an over boost is determined by the ECU, it cuts fuel to the injectors. Fuel cut is based on one thing and one thing only...the volume of air sensed by the AFM.
OAT does have an effect due to the increased density of air at lower temperatures. The IAT sensor in the AFM senses air temp, the ECU then adjusts to take into account the volume of denser air. as a result, you will hit FC at a lower boost level when it is cold outside.
A warning Paradox: This is the tech section...be very sure of what you are saying before you post. We do not "guess" or "I think it's because" in this section.
Found the coolant leak, it was the coolant line on the bottom of the iscv, the crappy ass 20 year old clamp must of lost its strength a few days ago when i cleaned the iscv, so i slapped a new clamp on there and boom no more coolant leaks! Now i just gotta find my vac leaks hahahahah