Ok, Now when I am in gear and driving and the RPM's get to 4k. the car either boggs down or like shudders real bad. but if i am out of gear and i rev it up to 3.5k rpms and dump the clutch, the rpm's climb fine. it is transmission or fuel problem? or somthing else.

BACKROUND:
the car is a 1987 turboII, it has 180,000 miles on it. mods are as follows.
> Walbro fuel pump
> HKS intake
> Racing beat turbo back exhaust
> Racing beat fuel cut controller
only problems i know of is it needs a oil change and the o2 sensor could use replacing.

thanks
-John

 

any one?

 

Look up 3800 hesitation.

Its kinda like you're secondary injectors arent activating under load. Could be a grounding issue.

Its not your o2 sensor.