Truck Surge

[singularity]

Hi folks,

 

I've got a 98 GMC 2500 4x4, 4 spd auto. The truck surges when cold. The RPMs drop and I have to plant my foot on the brake to keep from rolling forward. It almost feels like the torque converter is trying to lock up while idling in gear. It does idle fine out of gear.

 

Any ideas?

 

Thanks

[Toadz]

Possibly a failing/clogged EGR valve. Unplug it and see if it makes a difference.

[GMstrong]

Couuld be vacuum leak,maybe dirty tb,same with the maf.If the truck surges then it doesnt idle fine.