Question about dirty IAC Valve and MAF

[TSXSurf]

Can a dirty IAC Valve cause the Mass Air Flow sensor to misread at idle?

That might seem like a random question. The reason I ask is that the MAF on our Explorer was replaced before the IAC Valve was cleaned. The MAF was reading a high amount of airflow at idle and the technician replaced it (tried cleaning it first, but that didn't help).

Any thoughts? The intake gaskets were replaced first, so a leak should not have been causing the MAF to read high...

I've been reading and searching the threads but couldn't find an answer.

Thanks in advance...

 

[matt0248]

need more info, what year and engine?

 

[TSXSurf]

2003 4.0 V6

It's fixed now, just trying to decide if the MAF needed to be replaced.

 

[TSXSurf]

Anybody have any input on this?

Would a dirty/clogged IAC Valve cause the MAF to show high airflow at idle? or would it be the opposite?

 

[matt0248]

Anybody have any input on this?

Would a dirty/clogged IAC Valve cause the MAF to show high airflow at idle? or would it be the opposite?

A dirty or clogged IAC would not cuase it to show high airflow unless it was stuck open and the idle speed was actually higher than normal. IF the passage in the IAC was clogged the PCM would adjust the puse width to the IAC to open it up enough to get the proper idle speed. The reading from the MAF shoud reflect actual engine RPM and subsequent air flow throught it. if at a given idle speed the MAF is reading too high than the MAF signal is messed up.