Variable Idle When Warm Linked to MAF/Selin Translator

[SMZ300zxTT]

I bought my 95 300Z last summer and it has been problems ever since. I've done a ton load of upgrades and spent tons of cash on getting it where I want it. Now that I've got it close to where I want it I'm having trouble with an erratic or variable idle when warm.

I checked for vacuum leaks and fixed those
The ignition seems to run fine
I replaced O2 sensors and both of idle air control valves

I start it up cold and it runs fine for a few minutes till it warms up then the idle starts to get jumpy and nothing changed with the new parts. I've got a dual pop with Selin translator. It's set to AVG. I pull the plug off of the passenger side MAF and the car purs like a kitten but then it won't rev over 2500 rpm like that. So I need to figure out if it's a MAF or Selin translator problem.

Has anyone had problems with their dual pop/Selin translator configuration that has caused this?

[Ziggy1621]

Your Selin should be on ADD mode unless it is specifically been tuned for AVG, which 99.9% of them are not

[SMZ300zxTT]

I probably spent over $10k upgrading through SZ. They made my chip and they told me it should be on AVG when I asked them about this. I think the idle is running a little rich. The idle has seemed to have gotten better on it after the new parts were put on. Whenever I blip the throttle it seems to level out around 1,400 rpm for a second then goes to idle around 900 but it gets a little erratic when trying to do so almost wanting to die sometimes. I have a JWT 500 cam I was wondering if the cam could contribute to some of that. I tested the MAF sensors with the voltmeter and they seemed to check out okay per the FSM. These turbo cars add a whole new level of complexity to solving problems.

[Ziggy1621]

Yes they do. Ok, if they set you up for AVG, then that can't be it. I would give Jim a call at Selin and give him the serial number of the translator. I had an issue with one, and when I called in, it was part of a batch that had an issue. He quickly sent out a new one and then I returned the old one in the same box.

[SMZ300zxTT]

So talked to somebody @ SZ. They said my TPS might be out of adjustment. So I'm checking the TPS today. I don't know what you think about refurbished MAF but I ordered a couple from the local auto parts store to see what they do. The car runs fairly well but I couldn't get .8-1.5v out of them as in the FSM. Anyway hopefully I'm not burning all this $$ for nothing & I see improvement.

[Ziggy1621]

Did you call Jim Selin? I thought mine was MAF also, but it was the translator

[SMZ300zxTT]

I couldn't find a phone #. I sent an email but no reply. I only found an email on his site.

[Ziggy1621]

PM Sent

[SMZ300zxTT]

Thanks I've just about replaced and checked almost everything else. I'm about to take it to the dealer and have them do a computer diagnostic to see if there was something I missed. Yesterday I tried testing the TPS and resetting the throttle bodies with the TPS. SZ said they never have problems out of the translators unless it was the earlier models & those were affected by HID lights.

[Ziggy1621]

Mine was not an earlier model and I did not have HIDs. Not that I'm discounting SZ, but this is something I encountered and Jim admitted that it was a certain batch. I'm still betting my $ on it

[dhl_express83]

It seems like I have the exact problem... I bought the full dual maf kit about 6 months ago and it has worked fine until 2 days ago... The z began to have erratic idles when warmed up, it idled between 500 - 1500. It was right on the edge of stalling but it didn't. I tested the MAFs individually on another z. The MAFs are fine. I've also checked the vacuum hoses and idle related hoses and they are all fine... Then I tested the Translator on another z. The same erratic idle happened. I hope I didn't get a faulty batch... How do you konw if you got a faulty batch? I've sent Jim an email too... still awaiting for his responses...

[Ziggy1621]

Welcome to Nico!

If it did it on the other Z, then it is probably the translator. If you bought it 6 months ago, then I doubt you are in the faulty batch I was referring to as that was over a year ago. But it is electronics, so it could definitely 'glitch'. Jim is good and will take care of you!

[dhl_express83]

Welcome to Nico!

If it did it on the other Z, then it is probably the translator. If you bought it 6 months ago, then I doubt you are in the faulty batch I was referring to as that was over a year ago. But it is electronics, so it could definitely 'glitch'. Jim is good and will take care of you!

I dont mean to hijack this thread but thanks for the warm welcome

Yeah, I heard Jim is a good lad. But I just wish it was something simple like a leaking hose or a loose connection somwehere which I could fix... I can't wait to have some dual MAF mmmaadddnessss...

[dhl_express83]

Thanks I've just about replaced and checked almost everything else. I'm about to take it to the dealer and have them do a computer diagnostic to see if there was something I missed. Yesterday I tried testing the TPS and resetting the throttle bodies with the TPS. SZ said they never have problems out of the translators unless it was the earlier models & those were affected by HID lights.

Not sure if you have come across this: http://www.twinturbo.net/nissan/300zx/f ... today.html

You check if you have an older version of the translator, if you do, you can try the temporary fix by wrapping it with tin foil as suggested in the link.

[Jerrybrown5081]

Hey!
Sorry to revive an old thread, but I've been having the exact same issue.... Except mine will actually die out. Started as soon as I put my dual intake on, been trying to figure out the cause for a while now... How did this turn out? If someone could help that'd be great... Thanks!