98 6.5 k2500
 

grandson got this truck on a trade the engine starts good idles fine but as soon as you touch the footfeed it redlines full rpm mechanic says ip is cracked we R taking the top off to look at it and can clearly tell the mechanic could not see the pump much less the crack there is no excess fuel on engine . we was wondering if anybody had any ideas on what might be the prob. the little black box is new and moved to the fenderwall. thanx for lending a ear doc cod7

Could be the Throttle Position Sensor if you changed the PMD

well we changed the pump over the weekend got her back together bleed her out and she started run good could hit the throttle she would rev up and let off her and she backed right down we did'nt run her to long as we had to change that slip in joint on the coolant goin into the block.went to the parts store this a.m. got the snap joint put it together went to start her up and she would idle rough, I touch the throttle and she would run away on us, i slipped her into reverse and she would back down did this several times ,always the same result. Any ideas out there ? Thanks DOC