rebuilt jimwolf KA runs rough. documented tests.

[kroos268]

I've searched, and read, and tested many systems. Looking for more advice.

SYMPTOMS
1. idle is rough, and periodic. smooth, then rough, changing every few seconds. sometimes you may think you hear pop or backfire at idle, but could also be sounds of the engine choking.
2. vacuum gauge inside manifold shows flutter ~3unit only when idle is rough. otherwise steady.
3. pop\backfire can be heard at higher RPM and almost always during deceleration.
4. acceleration is usually nice.
5. power fluctuation can be felt while driving and holding RPM constant, at the same rate as idle fluctuation.


CURRENT HYPOTHESIS 's
jim wolf pre-programmed on the rich side?
there's an air leak im' just not finding it


TESTS COMPLETED
1. compression - PASS all cyl ~150
2. air leak - PASS. soaked intake mani and intercooler pipe seals.
3. MAF - PASS. multimeter\blow test on signal wire.
4. Cylinder drop - PASS. all injectors fire.
5. Timing - tuned? Advanced\Retarded timing for best idle. Distributor is on factory tooth, rotated to limit counter-clockwise. An additional tooth in the same direction did not benefit, spooled too soon(?), and ran hot.


CONFIGURATION
rebuild ka24de
yellow top injectors, nismo
Z32 MAF
jimwolf ATX ECU programmed for MTX
GT28 ball bearing turbo
intercooler
walboro 255

ps. I also see some oil pool up in the turbo inlet/outlet flanges.

thanks!
steve

[kroos268]

also, the second o2 sensor is not hooked up. only the sensor directly after the turbo downpipe. i read this didn't matter.

[kroos268]

bump? bump?

[DreamN]

Hook up your second o2 sensor.

[kroos268]

are you certain it is important? Not to downplay, but why... that is a significant install for I have new piping all the way out.

[ManoNegra]

also, the second o2 sensor is not hooked up. only the sensor directly after the turbo downpipe. i read this didn't matter.

S14? 2nd O2 is for emissions, monitors the cat. check engine light on?

intermittent vaccum leak would be my guess.

[kroos268]

S14? 2nd O2 is for emissions, monitors the cat. check engine light on?

intermittent vaccum leak would be my guess.

yes it is on. I have done the starter fluid test. Can an auto shop test for leak from my turbo outlet all the way to manifold?

[Gorilla Unit 33]

My O2 snesor has never been plugged in since i bought the car and it never gave me any problems like this..... then again im OBD1

[mattsil80wis]

Pressure test your system, from the turbo inlet. Fluctating vacuum at idle is a suretell sign of their being a leak someplace, not so much on the pipes, but also the IM itself.