Strange Engine Problem

[Chris Kulbaba]

Hey all...



My truck has been running flawlessly for the longest time. But for some reason, for no reason at all when I pull up to a light, or slow down to lower speeds the ST starts to almost stall out, but it doesnt it will idle extremely rough and the tach will jump around well under the 1000rpm point...



If I put it in neutral it gets back to normal, and then I can put it back into drive and things will be good for a while then out of nowhere it will do it again...



Any ideas anyone?



Much appreciated!

 

[Todd Z]

first, Clean the IAC, MAF and throttle body,



Then check the common vacuum elbow,



Then check/change fuel / air filter...



Then disconnect neg battery cable for 1/2 hour



IF those steps do not work,



Have it looked at..

Todd Z

 

[paul caughman]

i had the same problem about two months ago... it cleared its self about 2 weeks later

 

[Shawn Couture]

its the throutle body. The problem will come back just clean it very well or buy the part for 75.00

 

[Chris Kulbaba]

Well I actually cleaned my TB a few weeks ago... I also did the Seafoam project (2 weeks ago)....



I will try out the other suggestions by Todd and see what happens.

 

[Ian Gross]

Was it doing this before you cleaned your intake?

 

[Scott Heckler]

It sure sounds like the IAC that Todd had mentioned.



ScoTt

 

[Chris Kulbaba]

Ian, no, it didnt. But it didnt for the longest time after I had done it.



My estimate on how long ago I did the cleaning is way off, I think it must have been over a month ago, because I had no problems for a few weeks after I had done it.

 

[Dennis Mouser]

cleaning the throttle body helped for me, didn't notice anything cleaning the IAC but it's worth the shot, I finally made progress replacing the DPFE sensor for about 37.00