Engine/Transmission (1998.5 - 2002) truck dead on top end

[blowinsmoke]

im trying to help a friend out- his 98 24V starts missing whne he tries to accelerate above 1500 RPM. no check engine light, good fuel pressure (11lbs) and new fuel filter. he said it did this a few weeks ago so he let it sit for 24hrs and it ran fine and now it is acting up again. Im thinking either water or air in fuel but havent found any visible leaks or water when draining fuel filter. He has a blue chip FMS and a pusher pump but it does it even when it is turned off. any suggestions???

 

[KKlingbeil]

Have him get to an auto zone or wherever and check for codes. Codes do not always make a check engine light come on.

 

[blowinsmoke]

no codes at all

 

[BGarofalo]

I Had a similar problem with mine and it turned out to be a crank sensor. The truck ran fine up to midrange and then missed and bucked like crazy.