High idle and stalls

BLAZERS99

MEMBER
1999 CHEVROLET BLAZER
4.3L
V6
4WD
AUTOMATIC
139,780 MILES

I put in a new fuel regulator new gaskets new crank sensor new pigtail for crank position sensor it ran fine then the regulator went out so I put new one in and gaskets. It idles at 3,000 and if I goes under it shuts off unless I unplug mass air flow sensor then it steadily idles at 3000. Would the upper intake gasket be leaking or did I mess something up cleaning the MAF and IAC and TPS?

Saturday, April 15th, 2017 AT 6:09 PM

2 Replies

KEN L

MASTER CERTIFIED MECHANIC
51,598 POSTS

It sounds like something got messed up, is ti check engine light on? If not please run the codes anyway to see what part we need to look at.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Recheck the TPS connector to make sure its plugged in all the way,

Please let us know what happens.

Best, Ken

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Tuesday, April 18th, 2017 AT 11:53 AM

STEVE W.

MECHANIC
14,514 POSTS

Vacuum leak would be a start. The gasket for the injector to upper intake and the upper to lower are common issues, if they get moved just a bit they leak.

Then the IAC which is nothing but a computer controlled vacuum leak! Also check the EVAP purge solenoid. The plastic can easily get cracked on them and leak.

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Wednesday, April 19th, 2017 AT 9:57 PM