NissanTouge87

Okay, so i've been through the usual idle issue and stumbling issue threads and flowcharts.

My issues are rough idle (sounds like big cams, 282s or bigger), excessive fuel consumption and lack of powerband.

Driving the car, when cold, starts up just fine no hesitation or long cranking to start. Until it reaches operating temp it misses and studders, hesitated and backfires. Once the car reaches operating temp, it drives fine, just low on power and has a very speratic powerband, 2-3.5k its fine, dips off till 5k then opens up for 500rpm then drop hard until 7k. The idle jumps from 500 to 1k and sounds like it has huge cams, as previously stated.

So far I have done these things to try to fix, from the best of my memory not strict to this order:

Emissions delete
Resealed intake manifold with helicoil on all bolts
AAIC removal
Cleaned out IAC
Recleaned IAC
Replaced o2 sensor
Replaced o2 sensor again with skinny o2 sensor
Put on ebay WAI
replaced maf
replaced knock sensor
Compression test 190,190,165,190
replaced fuel injectors with a used KAde set
installed fuel pressure gauge (forgot what im getting but its FSM normal)
regrounded maf
tested TPS checked out ok
replaced coolant temp sensor
replaced pcv valve and hose
fixed crack in intake manifold where egr bolts to
complete tune up

basically im stumped, im basically down to thinking either a bum ECU or another leaky fuel injector. I pulled the ecu and took a look to see if it had the DSM common signs of being bad, since thats what community i was previously with. Ecu and boards looked immaculate and didnt smell burnt at all. As far as im aware of this is the original ecu. When i got the car it idled and drove fine. Then about 3 days after i bought it i lost 5th gear and it started loping on the idle and its been a battle to fix the lope for about 6 months now.

Any experts got advice? The wife said i cant turbo it untill it runs right, and well, im itching for boost.

jp314

Compression on one cylinder out of specification,
should be within 14psi of other cylinders.
Sticking valve? Worn rings?

Benito Malito

#3 is def out of spec and the other 3 are pretty high. I usually get 180 out of a tip top de.

clean throttle body and there is an air regulator on the back of the block undr the manifold that could be bad. pita to replace.

make sure maf is grounded at manifold I usually put it on the injector ground.

__________________
1992 SuperBlack VVL SE-R
1994 P10 KL0
2004 Forester XT SGM

NissanTouge87

Yeah, I couldn't remember the exsact specs and difference tolerence between cylinders. Again comming from the dsm game.

I have absolutly no idle controls besides the IAC bolted to the back of the intake manifold. The air regulator was bad so it was removed.

Would being 30psi low cause my issues? I'm getting mixed feedback and havn't been able to talk to my machinist yet. I can picture in my head how having low compression in the one cylinder would cause my idle loping, but I like to get a couple of opinions so I dont blindly start re-ringing my engine if it does not need to be.

NissanTouge87

update:
Talked to my machinist and he said it doesn't sound like a low compression issue, but it could be in a grey area. He usually sees idle problems with a completely dead cylinder. But he said hook up a vacuum gauge and check to see what it's idling at. Well after 3 days of searching for my boost/vac gauge, i bought a vacuum tester and hooked it up. My sr20de ides at a shaky 9psi. LOL