beems240sx
01-02-2010, 07:50 PM
my s13 SR began to start hard once winter came around and ive been having trouble with it ever since. its only when it sits over night and i go to start it that it just cranks and cranks. i know im not getting enough fuel. to be able to start the car i carry a can of carb cleaner with me at all times and spray in the BOV vacuum line. it starts when i do this which is why i know its a fuel issue.
Once the car is semi-warm, as in temp needle above C, it sputters and runs like crap. this is only below 2K rpm. its annoying because i normally shift at 2500 to 3000 on regular shifts. it will never stall on its own tho. its seems that once it gets the initial fire its ok.
i have replaced the coolant temp sensor already with no change. the sluggish while running leads me to believe my maf is dirty or needs to be swapped out, but this is only while its cold. ive also thought about the 02 sensor being faulty and keeping the ecu in an open loop, not allowing the sensor to regulate the mixture.
i was searching the forum and came across a thread talking about the orange wire that is the fused start signal that advances the timing during cold starts. can an sr start without this wire? when i bought my s14 completely stock someone had used a paper clip to jumper a missing fuse in the fuse box. i never figured out what it was for. is it possible this is it? i redid my whole fuse box when i tucked it all and left out this part.
Once the car is fully warmed up it runs perfect, pulls smooth and hard with perfect AFR's
any other ideas?
cliff notes:
cold starts in cold weather
already changed coolant temp sensor
sluggish while running under 2K rpm
mods:
S13 SR
S14 SR "WC" ECU
Front mount intercooler
Full 3" turbo back exhaust
ISIS intake manifold
Stock T25 at 14 PSI
Once the car is semi-warm, as in temp needle above C, it sputters and runs like crap. this is only below 2K rpm. its annoying because i normally shift at 2500 to 3000 on regular shifts. it will never stall on its own tho. its seems that once it gets the initial fire its ok.
i have replaced the coolant temp sensor already with no change. the sluggish while running leads me to believe my maf is dirty or needs to be swapped out, but this is only while its cold. ive also thought about the 02 sensor being faulty and keeping the ecu in an open loop, not allowing the sensor to regulate the mixture.
i was searching the forum and came across a thread talking about the orange wire that is the fused start signal that advances the timing during cold starts. can an sr start without this wire? when i bought my s14 completely stock someone had used a paper clip to jumper a missing fuse in the fuse box. i never figured out what it was for. is it possible this is it? i redid my whole fuse box when i tucked it all and left out this part.
Once the car is fully warmed up it runs perfect, pulls smooth and hard with perfect AFR's
any other ideas?
cliff notes:
cold starts in cold weather
already changed coolant temp sensor
sluggish while running under 2K rpm
mods:
S13 SR
S14 SR "WC" ECU
Front mount intercooler
Full 3" turbo back exhaust
ISIS intake manifold
Stock T25 at 14 PSI