SR20detMaf issues.

Okay I need help.

This motor is fighting me till the bitter end. It’s a s14 sr20det, bone stock other than a z32 maf, exhaust and an intercooler. Oh it has forged pistons now.

So after a full rebuild, the motor is having a single frustrating ass problem.

Unplug the maf, car runs awesome. Plug it in the car dies.

Now heres the fun part. Maf is unplugged, cylinder 3 doesn’t work. It has compression, spark and fuel. Unplugging the coil pack makes no difference. Plug the maf in, the car idles fine. Unplug the coil pack and the car runs like it does when the maf is unplugged.

We’ve changed maf’s (gone to a Z32), tried a new ignitor, checked vaccum leaks with a $2000 leak detector and changed coil packs. Nothing fixes the problem.

Only thing we haven’t checked is the ECU.

And yes it has gas and a good battery, fuel pump is good. Like I said the only problem is the no3 cylinder.

Is the ECU tuned for a Z32 MAf or do you have a AFC to compensate for the maf???

z32 maf does the same thing as the sr maf. ka24e maf does the same thing. Tunning isn’t an issue here.

It only fires on 3 cylinders when the maf is plugged in. what would cause either fuel or spark that is connected with maf to only affect one cylinder?

Hmm only thing i was going to say is tunning but if you dont think its that im not sure. Who did the rebuild? Anything you think might be offset with c. 3 or something wasnt balanced right? That doesnt really explain the other plugging issues. ~_~

the Z32 MAF won’t work if the ECU isn’t programed for it. it uses a different voltage. You might of had a bad SR MAF and now you have a good Z32 MAF but the ECU can’t talk to it. so it idles good, but when you rev it up it goes into the safety mode and runs rich.

Have you tried plugging in a stock SR maf that works? If the problem goes away then you’ve got your answer

Z32 maf works. Turns out it was a minor boost leak coupled with a shorting wire on the O2 sensor. It runs richer than sin without tuning on the z32 maf but the ecu is headed off to jim wolf this winter anyways.