Mystery flooding/rough idle issues RB20DET

[TBird713]

SAFC works awesome. Car is getting its plate tomorrow and wideband is getting plumbed in right after so i can tune it. Also rechecked the tps and ya i wasnt reading it wrong. Multimeter set at 20k ohms was giving me 0.36 closed and i think about 0.68 wot. 360-680 does NOT equal 2000-10000 but the voltages are set right, just doesnt like idle that much. New tps is ordered and they actually had one in Calgary. Hopefully will have it tomorrow for tuning.

Also, iacv was sitting in direct sunlight while i was doing wiring, and it was HOT today. 25+ with uv rating of 6-7 and that valve didnt budge at all. It was hot enough to probably make steam if i poured water on it. It and some of my tools were hot enough to instantly burn my hand so maybe its pooched too? Spring is effed either way and it isnt going back in.

As for the first testdrive with safc (no tune) to my surprise when flooring it through first and second and then coasting to a stop it IDLED. Idled around 1100 but dropped to 900ish fairly quick but at no time did it try stalling out. Its starting to scare me. Every day it changes its mind.

[Skym]

Easier to know that it's on idle contact via Nistune tuning software (light's up in software) or via Nissan's Consult diagnostic tool.

From what I understand, IACV needs voltage as well, not just heat.

Have you checked for faulty o2 sensor???

SAFC adjust's voltage from MAF to ECU, which makes ECU select different load cells on fuel, ignition maps (leaner or richer, retarded or advanced at same time). Designed for intake, exhaust mods.

Apexi used to have SITC that adjusted signal from CAS to adjust ignition timing. That's until PowerFC was made which replaced SITC, SAFC. They only use SAFC with podfilter, catback exhaust mods.

[TBird713]

Its got an apexi cone filter and 3"-3.5"-4"-5" tip and something is REALLY messed up.

http://www.youtube.com/watch?v=_9VgioMm1KQ

Sounds like your diagnosis of a faulty tps. It does this constantly though. You step on the gas and it just sputters and rpm doesnt go up but safc is telling me the afm is reading more air as turbo trys spooling up and tps voltage IS changing but that doesnt always mean it works right. Its parked at a gas station a couple miles away cuz thats as far as i got. When it first left my g-ma's house it was running fairly well but still rich because its cold. Barely made it up the hill to the gas station and it wouldnt go any furrther.

Im getting really !@#$ing sick of this car already.

[TBird713]

Car is having troubles starting and when it does after 5-6 cranks it barely holds idle (sounds lopey) and afr is reading 11 at most with random spikes to 16+. All while a SOLID plume of black smoke comes out the exhaust. Checked spark and A i could see it in broad daylight (bad) and B. it was orange (really bad). So trying a different ignitor pack and possibly fuel pump

[Skym]

When one of the TPS's (had 2x TPS fail) went on my car it didn't matter if used throttle engine still wanted to randomly stall.

But what I saw in videoclip was engine going suddenly very rich on A/F ratio gauge. Try unplugging MAF and start engine to see if engine idles (stock ECU can run without MAF. It's a stock ECU only feature and ECU should engage a revlimiter at 2500rpm). If engine idles, then it's obviously MAF related (sometimes MAF has bad solders inside square part of MAF, sometiems MAF can't be repaired) or SAFC tune is causing problems (set to rich on SAFC). Also check for intake leaks behind MAF, as MAF could be getting 2x air sources thus making ECU run engine rich.

Also you'll need to clear MAF error code on ECU afterwards (remove negative terminal on battery, stomp on brake pedal to drain any left over power, reconnect - terminal on battery).

Edit: Thinking about the A/F ratio and what it did in videoclip. It went lean, then very rich in a certain amount of seconds. It kind of points towards o2 sensor making ECU make engine go lean, then rich and not recovering (due to lazy o2 sensor).

Ignition timing should be adjusted to suit (if TPS is on idle contact and ECU should switch to idle stabilisation tables which adjust's the ignition timing +5 degrees and - 5 degrees to suit A/F ratio change at idle). Could be right about faulty TPS, lazy o2 sensor combined causing the problems.

What you need to do is check MAF first as above (plug it back in), then do the same with o2 sensor. Unplugging one of them is got to stop the problem.

MAF, TPS, o2 sensor affect fueling, so does ECU tune (especially if have aftermarket fuel pump), so that's where I would be looking. Worst case it could be a leaking injector or injectors causing engine to flood, stall.

[TBird713]

As an update, tps did nothing, and O2 is brand new. Also, this is exactly how it was idling http://www.youtube.com/watch?v=FV5UZfvJmts

Now it will not even turn over but it is getting fuel. I tested for spark again and this time got 3 orange sparks followed by nothing. whether it turned blue and i couldnt see it or it totally wasnt sparking i dont know but she dont run no more at all. Im fairly convinced its ignitor pack. However nobody in this town seems to have an rb20 (ya okay) and/or is willing to borrow me one for 2 minutes. Car is now sitting until June when I start getting paid again. Havent had a job since Nov (sucks)

[TBird713]

Tested a working ignitor pack. Guess what.....NOT A DAMN THING >_> Fuel pump is already ripped out and a 255 will be going in asap. I don't see what else would do these things. Had a HD mechanic tell me fuel pumps will overfuel like crazy and then not work at all when they go (sometimes) which would confirm this. If a fuel pump doesnt work im gonna be uber stumped.

[TBird713]

Figured i may as well share a couple vids incase you were curious as to how it runs lol

This was shot a short while ago. Show it running like ass with occasional missing everywhere.

http://www.youtube.com/watch?v=gWxDcVB0VtA

This was today. Now running on 4/6 cylinders. Unplugging my fuel pump resistor pack under the hood...brought the idle up before it quit. Trying a working one tomorrow.

http://www.youtube.com/watch?v=2F5C8MBxK5U

[Skym]

Try changing ECU, as sometimes it can be ECU is faulty, damaged internally (ECU can overfuel engine when 24 pin EPROM chip inside ECU dislodges from 24 pin EPROM socket or main circuit board) or ECU is not plugged in properly to main loom (plug is bent). Sometimes it can be as simple as bad earths or bad earth somewhere.

[TBird713]

We've tried that :/ We tried 2 different ones. One thing I found tonight however is regarding the fuel system. Changed the fuel pump voltage resistor pack, no change. I now have my buddies fuel pump in (stock) and guess what...no change!!! I borrowed by buddies fuel pressure gauge and tested fuel pressure. Before the rail on prime was 45psi. Cranking was around 38 i think but continued to go down and jump back up (pump is obviously working). Now for the fun part. the return line. Prime there was nothing. Ok. Cranking...there was nothing...hmm. I then pinched the return line after my guage and had my mom crank it while i held the relief valve open on the gauge, so basically rerouting the return from my tank to my little container. And there was no movement in the lines. Which tells me ALL the fuel going into the rail is getting dumped into the cylinders. So at this point unless ive just been huffing to many gas fumes my regulator has stopped working and is stuck shut. even with the vacuum lines hooked up (which seems weird, also getting no fuel out of vacuum lines)

does this make sense? Its not a matter of not enough air, just no fuel going back to the tank so its just too much fuel. Which would explain the small explosion I got in my exhaust followed by two minutes of smoke slowly coming out the tailpipe.

[Skym]

Makes sense. Too high fuel pressure at idle and combined with engine sucking fuel out of injectors at idle (vacuum), engine runs rich and stalls.

The FPR that returns fuel to fueltank does fail (I think the diaphram inside fails) on Skylines. Rare (most people change FPR out before it becomes a problem) but does happen.

[TBird713]

Oh it does happen. And it appears to have happened to me :P I still wanna double check that the 4" hose coming off the fpr isnt collapsed but im pretty sure its the fpr. Heres the video :P Whoooole lotta nothin.

http://www.youtube.com/watch?v=4rNOkxYJZLo

[Skym]

At least you found the cause and everything else seems to be working ok (that you checked).

Good excuse to fit a rebuildable SARD, Aeromotive or similar FPR.

[TBird713]

Sorta. Id need a new rail too then. Stock one is seized shut so that has to get replaced no matter what which is way cheaper than a new rail and regulator. Especially since i have no more plans with this car :P

I'll find out tomorrow if this fixes things.

[Skym]

Crossing fingers.