How Diagnose a bad GM maf sensor?

[TAMA_player]

Hi Guys.

I have a problem with my car, after i disassemble the upper inter cooler pipe, to figure what i need to install a new Water/air IC, i take the measures, and then i reassemble all, start the car normally, it idles fine but past 5K rpm the car runs lean

Mods are:
dsmchips stage3 paired with FIC 650's
Blow through 3" GM MAF with translator
255lph with fuelab 515 regulator @35 psi
AEM wideband

The car was running great before the intercooler disassemble, i triple check everything for leaks. And everything seems ok.

Can you helpme to figure what goes wrong?
Seems the GM sensor is running good, or maybe failing at certain flow rate?

Hope you can give some advice ^_^

Abner

 

[everydaydriven]

Sounds like a boost leak, do a test using soapy water so you can see it! Maby the maf us installed backwards??? Idk I don't use a gm maf. I use hairspray when I put my couplers on just so they for a stick tight seal after clamped an dried. See what that does.
Thanks,
Jake

 

[oreo4g63]

the little honeycomb in the maf sensor may be bent. i had that problem with mine. if u still have it in.

 

[big_d]

Pull a datalog and post it up. Do a nice 4th or 3rd gear pull, plot MAF frequency and see if anything odd is occuring.

 

[TAMA_player]

Ok, an update in this....

I disassemble everything and get cleaned, and put it again, and same symptoms. Running good at idle and leaning out at high rpms.

I travel 2 hours just to bring back my old 1g maf.
Today i installed it, and the car run pig rich. I try to "tune" with the FPR, and i get a almost fine fuel trims.

15.1 at idle and 12.7 at wot, (open loop mode).

Get back to Maf-T, to find i run lean again, then move the selector to 3.5" GM maf and the car run rich.

My conclusions is i get a 45% less flow reading just by remove the GM maf and install again..... ??

At this point is best to run rich than lean, until the ECMlink returns from USA. I just make a great hate for mafs... i will be converting to speed density as soon as the link get back ^_^. Is Speed density good for Roadracing? i read almost everything about SD but all the info is for Dragracing.....

Thanks guys for all the input you give me!!
Oreo4g63 remember me that i can use my old 1g maf...

My problem with GM maf dont get corrected but at least i can run again, so i think i will mark this as solved...
And ill be posting my custom Air to water intercooler setup for Roadracing (radiator between Rear diff and Fuel tank).

 

[TAMA_player]

Okay.

Removing the GM maf makes the problem bigger.
Last week i find the real problem: Blown inyector orings.
Thats all.