SR issues

Blackzenki82

(OO\_SKYLINE_/OO)
Driver
so yeah, trying to finish this car off, and I'm having a few issues...

idles OK, a sputter here and there....

under acceleration, it's smooth till about 1500RPM then starts breaking up, popping, and just losing power, i've already put two different MAF's on the car, did a boost/vac leak test, so system is sealed...

i checked time, with a light, and was close enough for gov'mnt work, if not spot on...

i also checked TPS signal, was at .57V and put it at the .45 as used by Nissan...

engine grounds were loose, so i tightened, and even added one on the driver side... and that helped with the idle, as well as setting the TPS...

tomorrow I'm going to pull the valve cover off, and check cam timing, and restab the CAS....


to me, it feels like a boost/vac leak, but like i said, i put an aircompressor on the turbo inlet, and found all leaks (at the couplers), and even went ang got a GReddy hot pipe and HKS SSQV with super low miles for it (as the TurboXS RFL that was on it was leaking like a bitch, and still, no joy..

SO, with that being said, there's a few more things i'm going to check-

Cam/CAS timing
MAF signal (as it MAY be the problem)
spark plug gaps
compression test (although 0mile motor built by a professional)




one more thing, with a blown T25 cause it to run like that? i noticed the T25 on it has a fair amount of shaft play, but not as bad as i've seen on some cars, and does spin freely....

usually i handle my own shit, but here i'm getting kinda stumped, especially if my cam timing ISN'T off....
 
Could be your coil packs. Also try an ignitor if you can. Check your fuel pump to make sure its getting proper voltage. Fuel pressure? Go over the wiring especially if you upgraded maf's between having a running sr and getting built (if it was ever running).
 
fuel pump.


had the same problem on a friends sr. thought it was maf and other shit and turned out to be fuel pump
 
thanks guys, if it were a stock pump, would it run an SR? or cause said bogging and break up?

tomorrow, i'll pull the plugs, and check the FP...


also, it was suggested to be a bad MAF on another forum, and my reply was this....

i'm thinking it might be the maf wiring too


oh the harness side, it was five wires, on the pig tail side, three wires...

so i did white to white, black to black, and black with stripe to black with stripe... didn't know what to do with the other two wires coming out of the harness, the brown one, and the black w/silver dots (ground)
 
no i dont think the pump should be the problem unless massively dirty my friend has a stock fuel pump on his sr and it runs fine
 
Im not saying its your fuel pump, but wtf would you trust a 15+ year old pump on your freshly built SR?
 
listen to tony, he is a smart guy.....change your fuel pump.

My car useto sputter when in boost at high rpms...just one of the many problem of my sr....turned out my plugs weren't gapped correctly.
 
well today i....

gapped the plugs (were at .45!)
reset/checked cam timing/CAS

car still bogged...


ordered a 255 fuel pump from enjuku, seems as if the car isn't getting enough gas, when it bogs and back fires, no black smoke comes out...

also, while clawhammer and i were trying to get a LED to work on the ECU, a relay kept clicking in the fuse panel... my assumption is that it was the fuel pump relay, turning the pump on and off to maintain pressure due to a leaky/faulty pump...

compression is 150 x4 with no more than a 2psi variance... so that shit's on point, and motors good....



thoughts?
____________
 
figure out your electrical issue and do the fuel pump relay mod while you're at it. idk what you gapped your plugs to, hopefully high .20's. good thing replacing that old pump anyway.
 
well today i....

gapped the plugs (were at .45!)
reset/checked cam timing/CAS

car still bogged...


ordered a 255 fuel pump from enjuku, seems as if the car isn't getting enough gas, when it bogs and back fires, no black smoke comes out...

also, while clawhammer and i were trying to get a LED to work on the ECU, a relay kept clicking in the fuse panel... my assumption is that it was the fuel pump relay, turning the pump on and off to maintain pressure due to a leaky/faulty pump...

compression is 150 x4 with no more than a 2psi variance... so that shit's on point, and motors good....



thoughts?
____________

your pump is on all the time when the car is running, fuel pressure regulator is what keeps it at the right fuel press

ps can be the relay
 
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