rpms drop while pressing the brake to stop

Asked by Feb 09, 2016 at 02:43 AM about the 1995 GMC Sierra C/K 2500

Question type: Maintenance & Repair

I have a 95 k2500 sierra 5.7l v8 not a vortex  with
158000 miles that has recently started dropping
the rpms when I slow to a stop but once I am
completely  stop the rmps stay normal and it idles
fine. Sometime it also does this when I am driving
and try to stay at a constant speed it drops down
and back up if not while I accelerate tho after it has
been warmed up it does this severely and it will die
has I am almost stopped and then I can restart it
just fine and it goes back to just dropping when I
go to stop again for awhile.

I have put a new alternator,battery, I cleaned the
iac valve,I added sea for straight to the injection
vacuum hose and put some in my gas tank.

I have had the code reader hooked up to it and no
codes. The engine light is not on ever either

Can anyone please help me
Has anyone else had this problem and got it fixed.

3 Answers


May have to replace IAC valve sometimes cleaning does not work. Valve maybe bad.


And the port for the IAC needs to be cleaned out good as well. Dirty injectors also, I see you Sea Foamed it tho. Also it may be that the fuel regulator in the TBI would need to be rebuilt, the spring in there goes weak causing low fuel pressure threw the injectors.

Thank you I will see what I can try those will this do it worse the warmer it gets and the more you drive it at the time

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