Chevy 5.7 4x4 stalls
 

I wanted to say thx for all the help on fixing my truck. It runs great now.
Replaceing the gas tank, fuel pump and assembally fixed it good.

However it still has a bit of tweeking to go. Seems that when I drive it and let off the gas it sounds like its about to stall. I can notice this when I stop for a stop sign, when I let off the gas she idles right down does this chug thing. Chug... Chug... Chug... Idles up to normal.
While it is doing its Chug thing seems like there is loss of power as the heater fan slows down and then speeds up as it does its thing lol.
It is really noticeable when backing out of the drive way cept instead of it almost stalling it general does.

My gut feeling is telling me vacumn. How ever Im a computer nerd and a wanna be mechanic so Im leaving this question to the pros!

Thx a ton for all the help its very appriciated.

RE: Chevy 5.7 4x4 stalls
 

What year truck? Did you change the filter?


Spell check doesn't work here.

RE: Chevy 5.7 4x4 stalls
 

Oh sorry. lol
It is a 1990, I have replaced the fuel filter.
The only thing on the fuel side I haven't replaced is the lines.

RE: Chevy 5.7 4x4 stalls
 

In my experience you can hear a vaccuum leak. Maybe some of the other guys will be able to help.

RE: Chevy 5.7 4x4 stalls
 

most likely an idle motor..or IAC...no ses lite?

RE: Chevy 5.7 4x4 stalls
 

CAI = Cold Air Intake
IAC = I Am Confused

RE: Chevy 5.7 4x4 stalls
 

idle air control

RE: Chevy 5.7 4x4 stalls
 

Excellent I look forward to replaceing it. It will be a Cheap fix. Thx all.


STANDARD MOTOR PRODUCTS Part # AC1 https://www.rockauto.com/catalog/images/MoreInfo.gif {IDLE AIR CONTROL VALVE}[/align]$42.79$0.00$42.79

RE: Chevy 5.7 4x4 stalls
 

Well I replaced the IAC but to no avail. It still stalls.
The one thing I did notice though is that now that it is winter and cold out it runs fine while it is frozen like a block of ice. Once I get to town and the motor is warm she starts with the problem again.
Anything else worth looking into? EGR valve perhaps?

Thx for the help everyone.

RE: Chevy 5.7 4x4 stalls
 

egr faulty would make her idle rough..

low idle is either the iac you replaced..the pcm which is very doubtful...or a mechanical issue with your throttle body