hi im kinda new to this forum but ive had a couple chevy trucks.
heres my problem i have a 94 chevy silverado ext cab 4x4 z71
i just did plugs and wires and a new thermostat.
im having an issues with going in reverse. in park drive and nutural it idles just fine great accually. especially after the new plugs. but when i shift in to rever (when its all warmed up ) i get this sporatic idle and its up and down all over the place. some times it has died on me. if i try to go along distance in reverse giving it a little more gas it will kinda slug down
it just feels like somethings not getting enough gas in reverse.

i could really use some help on this one its been doing this for about 3 months now.

 

How many miles on truck and transmission?

 

the truck has about 230000 miles.
the tranny has about the same amount we just switched a transmission from the same exact truck that my brother had. to this truck. there was no shaving or anything in the pan everything was clean and is shifts really smoothly.

 

Your reverse gear may be going.g out.
A tranny shop can plug a tool Into your ecu and let you know

 

does it need to be a transmission shop or just any shop that would have that tool.

 

Well, it is a specialty tool.
You could try an auto repair shop as a possibility.
But a reputable full service tranny shop SHOULD have 1