1990 B2600i 4x4 My truck stalls when decelerating at a stop sign. It seems to run fine when cold just when it gets warmed up it stalls. Also it seems to run fine on the interstate. I've check for vacuum leak and have not detected anything. The cap, rotor, wire and plugs are fairly new. less than a year old.

The problem seems to start up quickly.

Any suggestions? Thanks

 

There are a lot of other things that you can check or clean without spending much money:
MAF sensor, Intake air temp sensor, EGR valve, clean throttle body, clean EGR ports, Idle air Control valve and so on.
I hope you stumble on the cause of your problem.

 

I found that there is a port on the back of the intake manifold that was missing a plug. Once I installed a plug it did not stumble at a stop light any more. Thanks for the advice

 

You are welcome and thanks for the feedback!