SR20DET: Rough Idle, What the...

Spooling Nismo · 11-19-2008, 01:08 PM

Ok I need some help with this one. I am working on an S14 with and S14 SR20det that is idling really rough and smokes black (rich). We have checked the MAF and swapped it with other single cam and SR MAFs, no change. Checked the grounds, voltage, signal and the wires from MAF to ECU, all good. Checked for boost/vac, fuel/injectors/o-rings leaks, none of any kind. Did find that covering 95% of the MAF senor port hole itself (not the air inlet chamber of the MAF) the car seems to run much better. WTF Lost...

The MAF signal voltage while idling rough is around 1.7v and when covering the MAF senor port, running good is around 1.5v. The only thing I can think of is maybe crap ECU. Any clues or similar issue you guys have run into? Any help would be greatly appreciated.

Spooling Nismo · 12-05-2008, 01:55 PM

Update...

We have tried swaping ECUs, still no change. Anyone...Anything...

Spooling Nismo · 12-07-2008, 02:33 AM

So I learned something new today. Didn't really think about this at first but turns out you can not run a S13 sr or single cam MAF on an S14 sr. It will cause the above problems. Donno if that goes for the opposite but the S14 sr ecu must have the S14 sr MAF run with it. Unless of course you are rom tuned for larger MAFs. But the car is running great now, hope this helps anyone out in the future.

Nutter_SR20DET · 12-08-2008, 10:09 AM

Quote:

Originally Posted by Spooling Nismo

Ok I need some help with this one. I am working on an S14 with and S14 SR20det that is idling really rough and smokes black (rich). We have checked the MAF and swapped it with other single cam and SR MAFs, no change. Checked the grounds, voltage, signal and the wires from MAF to ECU, all good. Checked for boost/vac, fuel/injectors/o-rings leaks, none of any kind. Did find that covering 95% of the MAF senor port hole itself (not the air inlet chamber of the MAF) the car seems to run much better. WTF Lost...

The MAF signal voltage while idling rough is around 1.7v and when covering the MAF senor port, running good is around 1.5v. The only thing I can think of is maybe crap ECU. Any clues or similar issue you guys have run into? Any help would be greatly appreciated.

Yea I have a similar issue with the rough idle but im using an S13 SR20DET Blacktop, Im not 100% but im thinkin the ECU needs to be re-tuned. If ya get it runnin right let me know what you did so i can get my baby runnin as well.