Thread: Still can't figure out my idle/timing issues, need to pick some brains!

So I did my VE swap over a year ago. The engine runs great (especially now that VVL works) for the most part, but I have a few idle/timing issues I just can't figure out. First I'll talk about the timing issue. Normally, you do the whole process of warming it up, rev at 2k for 2 minutes, let idle for 1 minute, then shut it off, unplug the TPS, restart and rev a couple times and proceed to adjust timing. Well, as soon as I unplug the TPS, it revs to 2,500 rpm and does not budge any lower not matter what I do. I even screwed the plunger on the AICV valve closed and it does nothing. I am at a total loss here as to what to do, so I plug it back in and time it with the TPS plugged in (been putting it at 15°TDC - Is this correct for a P11 VE?). So I don't know if it's perfectly timed or not, that's all I can go off of. Also, if you set the TPS to the correct kΩ and voltage that the FSM says to, it revs to 2,500. I have to physically move the TPS all the way to the closed position to get it to idle at a normal RPM.

Second is my idling issue. It will idle fine most of the time, but if you drive it and come to a stop it will sit at idle for a second or two, then just die. This is at a stock idle of about 750rpm. If I set the idle to 1,100rpm with the AICV plunger screw, it will drop to 300 rpm or so and shoot back up. Any ideas?

For reference, here is my setup. The only thing I can think of at this point is that JWT didn't adjust the ECU correctly when I told them what I had. I know they usually tell people to use the DE AICV.

P11 SR20VE in a 96 OBDII G20.
Has a JWT 200SX SE-R OBDII flashed ECU for the VE
Z32 MAF
VE Distributor
VE AICV
Brand New P10/B14 DE TPS on P10 DE Throttle body
DE OBDII o2 sensors
OBDII stock harness modified to run VE components
DE Air valve is plugged in, but no hoses hooked up (had them hooked up originally, but deleted them thinking it may fix the issue, nothing changed).

This has me stumped for the past year, and it is driving me crazy. I just want the thing to be a reliable DD that doesn't have retarded quirks, ha ha.

Tried using consult to force it in timing mode? Maybe it's not actually getting to timing/idle adjustment mode

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i had a similar issue a while back at the auto electricans, and they eventually discovered they weren't connecting the tps properly.maybe this is what your doing?

once you used your multimeter to establish the 0.45v? needed by the tps, and ecu needs to know what 0v through the tps is first! , and i believe the trick is to put the ignition into the (on) position a couple of times (ecu reads 0v through the tps), before you connect the tps (ecu now reads 0.45v) and adjusts itself accordingly. high idle was my result. once i got that right, the thing settled at 900rpm, what is what my nismotronic is set to.

if you got a de ecu, then yes i think 15deg is right. you should be able to tell its in timing mode, but consult would help.

I can try the ecu learn thing, thanks for that tid bit. I don't have consult, so I'm out of luck there, lol. It's a DE ecu flash tuned for the VE, not just a plain DE ecu if that matters any.

Hey I'll text you this, but Jeff (the guy that runs NASA-AZ with the blue and orange miata) owns/runs Desert Diagnostics, he has a Nissan Consult 1, 2 and 3. He'd easily be able to do it for you (plus he's of course a wiring and diagnostics guru). He's fixed a ton of my weird electrical demons over the years.

I'll shoot you his info.

Besides the location of the cupholders in the B13&B14 (lol) - issues with the idle is my #1 gripe with our cars. It's like a mystery.

i had bad issues with my VE for 3 years, boggin and etc. turned out to be a bad O2 sensor. at idle it should fluctuate back and forth from lean to rich

I just replaced the front sensor, but the rear sensor is still the old stock one. Maybe that needs to be replaced as well, lol.

Update: Still having the same issues. I haven't found any vacuum leaks at all, but the vacuum line from the intake manifold to the brake booster is sort of kinked. I need to figure out a nice elegant solution that looks nice there. It never had the issue of dying randomly until after I accidentally ground the positive battery post while it was running (ratchet when I was loosening the distributor bolts), anyone know what this could have done? I'm not the best with electronics, I'm a mechanical guy, ha ha.

BTW, I do know my cat is bad, so I'm replacing that soon (already have it, just need to get someone to weld in a bung for the rear o2 sensor for me, ha ha).




I was going to hit Jeff up, but at the moment, I can't really afford to pay a professional dude to work on my stuff. I'll have to try to figure it out via forums and trial and error for now :/.



My rear o2 sensor was indeed bad, so I replaced it, but still having the same issues, lol. At least I can rule that out!

If you arced the battery terminals you need to inspect all of the fuses and fusible links for damage or partially blown/melting. Check all of them under hood and dash. Also recheck/retighten all grounds on engine and make sure ground cable from battery is properly tight and free of corrosion where it bolts to the body and engine/transmission.