I have a 90 model silverado. Just put ANOTHER engine in it, this makes #2. The truck idles great, even when you're under the hood giving it gas, it has good throttle response. When I put the truck in gear and give it gas it respondes ok, but when heavy on the gas it hesitates, misses, until I let off accelerator.
I CALLED myself checking the plugs.
The fuel pump has been rebuilt.
The filter has been replaced when 1st engine was put in.
Any advice would be helpful and appreciated. Thanks