1G MAF upgrade or just replace?

[jonnyox]

So I’m like 99% sure my MAF is bad. I unplug the MAF and my idle is completely perfect. Plug it back in and I'm dropping below 1k RPM’s and jumping back up every few seconds. I don’t know if I should upgrade the MAF to a 2g MAF it just replace it with another 1g.

 

[pauleyman]

so i’m like 99% sure my MAF is bad. i unplug the maf and my idle is completely perfect. plug it back in and i’m dropping below 1k rpm’s and jumping back up every few seconds. i don’t know if i should upgrade the maf to a 2g maf it just replace it with another 1g.

Sounds more like a problem in the idle circuit. Unplugging the MAF just changes things. Diagnose the problem. Do not throw parts at it. Have you checked idle speed control? BISS? Base timing? Did this start all of a sudden or gradually over time?

Additionally there is no point in " upgrading" the MAF when you can't outflow the one you have. You also can't just drop it in. Doesn't work that way.

 

[92AWDHX40]

Yep just replace what you have.

 

[pauleyman]

Yep just replace what you have.

If that is even the problem. You must determine that first. If you have determined the maf is "bad" because the car runs better with it unplugged your assessment is not correct.

 

[92AWDHX40]

Yep

 

[pauleyman]

OP please look into the resources section. A wealth of information to be had.

https://www.dsmtuners.com/threads/idle-surge-problems-and-solutions.172175/

Found here.

Resources

DSM Resources Tech Library. Read through it all, and if you have a lot of experience with DSMs, contribute articles and tutorials to help grow the collective knowledge.

www.dsmtuners.com

 

[Spleen8urLSX]

Paul absolutely nailed it, very well COULD be the MAF, but there’s things to check first.

Along with that, even if there was a gain to be had you’d cause new issues. I once tossed a 1g turbo MAF on my car when it was still non-turbo to see what would happen, datalogging and my wideband showed everything to be perfectly fine as well as it ran just as it did before, however any time I’d go more than just a little throttle it’d be fine until I let off and it would stall out and have to be restarted. This is due to the “MAF signal reset” pin in the turbo ECU that the NT ECU (and wiring harness) does not have. The 2g MAF utilizes it as well. Now being a 2g MAF and 1g turbo MAF reads differently I can’t say that your car would even run correctly, but the signal reset issue would be an issue nonetheless.

If your problem does end up being the MAF then a replacement NT MAF is inexpensive and easy enough to get, plus will plug in without building a jumper harness. If you’re looking to improve airflow a K&N drop in filter and cutting the air can properly is as good as it gets for now but don’t expect a difference you can feel.

 

[RamenPride]

It would probably be a good idea to confirm the MAF is indeed dead before doing anything. Had an issue where the car idled ok, but fell on it's face trying to go over 15mph. Datalogger confirmed it was a dead MAF (didn't read anything). As far as upgrading, not sure if there would be any benefit on an NT.

 

[dwb]

Show car? I want to see more pics!

It's common to notice better idle conditions when unplugging the MAF if you have other underlying issues that affect the idle. Unplugging the MAF just puts it into limp mode. The very fact that it changes the behavior when unplugged sounds *to me* like your MAF is perfectly fine. If it's not triggering a check engine light, you should diagnose your idle issues:

• Adjust your BISS per the FSM and make sure the o ring is healthy
• Check for vacuum leaks between the throttle plate and head
• Verify your ISC is working properly and the o ring is heathy
• Check your ECU for capacitor leakage (or snap a clear pic of the circuit board and post it here)
• FIAV may be faulty (only way to test is to block it off)
• Idle position switch should be checked with a multimeter for continuity to ground when the throttle is closed
• Throttle plate may be binding up or held open by the throttle cable being adjusted too tight.

 

[jonnyox]

Sounds more like a problem in the idle circuit. Unplugging the MAF just changes things. Diagnose the problem. Do not throw parts at it. Have you checked idle speed control? BISS? Base timing? Did this start all of a sudden or gradually over time?

Additionally there is no point in " upgrading" the MAF when you can't outflow the one you have. You also can't just drop it in. Doesn't work that way.

Show car? I want to see more pics!

It's common to notice better idle conditions when unplugging the MAF if you have other underlying issues that affect the idle. Unplugging the MAF just puts it into limp mode. The very fact that it changes the behavior when unplugged sounds *to me* like your MAF is perfectly fine. If it's not triggering a check engine light, you should diagnose your idle issues:

• Adjust your BISS per the FSM and make sure the o ring is healthy
• Check for vacuum leaks between the throttle plate and head
• Verify your ISC is working properly and the o ring is heathy
• Check your ECU for capacitor leakage (or snap a clear pic of the circuit board and post it here)
• FIAV may be faulty (only way to test is to block it off)
• Idle position switch should be checked with a multimeter for continuity to ground when the throttle is closed
• Throttle plate may be binding up or held open by the throttle cable being adjusted too tight.

I adjusted the BISS, idles a little better but still surges. I’ll have to pick up a multimeter to test my ISC.

Thank you for the list. I also updated my pictures if you wanna check it out

 

[92AWDHX40]

For one ive owned a couple of non turbos, never had a maf issue but, the parts are now ancient, hope you fix your issue.

 

[pauleyman]

I adjusted the BISS, idles a little better but still surges. I’ll have to pick up a multimeter to test my ISC.

Thank you for the list. I also updated my pictures if you wanna check it out

Did you adjust the biss according to procedure? Ground the check connector to take isc out of the loop.

 

[jonnyox]

Did you adjust the biss according to procedure? Ground the check connector to take isc out of the loop.

no i adjusted correctly