S14 RB25 Problem!

[silvergsx95]

Ok im new to the whole nissan thing jus bought a rb25 series1 powered s14, the mods are as follows....Mckinney front mount kit with tial 50mm, greddy intake mani., q45 throtle body stock turbo and j60 maf, 3inch downpipe and full exhaust.

Heres the problem since ive bought the car it wont rev all the way to rev limiter it goes to like 5500 and jus dies wont rev any higher its only on stock boost, ive already tried a new MAF. I put new plugs in and still no change, the car runs perfect up until 5k rpm then it dies out. no rough idle or anything. I NEED HELP!!! Please give me some suggestions...ive read some posts about the coils so im going to check them. Let me know what else to check

[RB24D]

do you have good fuel pressure and how old is the filter?

[KlanjacOFF]

Check the TPS for proper voltage?

[silvergsx95]

yeah good fuel pressure brand new filter. And how do i check for proper voltage on the tps?

[mott6904]

what did you gap the plugs to? Try lowering the gap to .8mm and see if that helps.

[ANVIL]

what ecu are you running? i could be wrong but i thought when you switch maf's that messes things up unless its tuned for it.

[silvergsx95]

my ecu code is mec-r531 a1 3z25 on the top of the ecu is where i found that code on the side next to the LED code check is a diff. code its mec-r531 a1 6928...i dont have a clue about this so i need all the help i can get! Thanx every1

[mott6904]

did you check your tps voltage or what your plugs were gapped at. People are trying to help you but if you dont take the advice then theres no sense in helping you.

[KlanjacOFF]

Wait, what fuel pump is on it? Could be fuel starvation up top. Also what MAF did you switch the J30 one with? Put a stock one on and see what happens.

[Yellow4g63]

What kind of codes is the ecu throwing? might be a bad CAS? boost leak.

[silvergsx95]

What kind of codes is the ecu throwing? might be a bad CAS? boost leak.

I dont have any codes and i just clean my maf and checked the voltage on the tps it reads 5v....still missfiring i dont know what else i can try.

[silvergsx95]

ok this is what ive done so far...i honda-bonded my coil packs nuthing changed...ran a boost leak test checked out good, gapped my plugs to .8 Everything is good execpt for i checked the voltage on the throtle body it checked out at 5v but i unplug the plugs on the tps and it runs exactly the same nuthing changes i can drive it and everything...any input?

[silvergsx95]

ok this is what ive done today....set my tps to .45v with the throtle closed and 4.5v with it open, so thats checked out and ive added 2 more grounds to the engine checked the voltage at the maf everything checked out...any other ideas any1?

[240z4u]

Do you have the stock MAF on your car? Thats certainly the problem if your not tuned for it.

Fuel pressure is good? How do you know?

Do you have a wideband? Troubleshooting without a wideband sucks.

Evan

[silvergsx95]

i got a fuel pressure gauge and no wideband...

[silvergsx95]

I jus got an ecu code out its code#54 its for a/t **** would that be my problem or no?

[silvergsx95]

can anyone help me?!?!?!

[Carl H]

an auto ecu will run an engine just fine, just will throw the auto ecu missing code (54).what fuel pump is in the car...if stock it needs to go asap.you mentioned it has an external gate...is there a larger turbo as well?

[silvergsx95]

an auto ecu will run an engine just fine, just will throw the auto ecu missing code (54).what fuel pump is in the car...if stock it needs to go asap.you mentioned it has an external gate...is there a larger turbo as well?

it has a walbro 255 no its jus the stock turbo...