X-J

88 4.0 auto 4wd
While in reverse on flat ground everything is ok.
while in reverse backin uphill, or giving it gas the engine hesitates,
i.e = hold down brake and - 1,500 rpms and up acts like a rev-limiter, no power, rpms flutter up & down to 900 to 1500
-has trans fluid
-thanks
-have a good weekend

solderjunkie

Check your engine grounds first. The cable above the filter, the small ground from the cable-end to the inner fender, and the strap to the bulkhead behind the valve cover.

Loosen the bolt a bit, then retighten it.

X-J

ok, ill check, i dont think there is a ground strap on the back side of the head,
if not ill put one , the wiring is a little butcherd when i bought it.
what dose the grounds have something to do with the computer when in reverse ?
it dose seem electrical related . motor mounts are good.

solderjunkie

Everything powertrain-related grounds through the block... then through the batt negative cable.

Going in reverse and mashing the gas shifts the entire powertrain out-of-position just a bit.

If you were grounding through the exhaust or differential it will show-up more when shifting the weight around.

X-J

The cable above the filter, - ok
the small ground from the cable-end to the inner fender, - ok
and the strap to the bulkhead behind the valve cover. - ok

still a problem

X-J

88 4.0 auto 4wd
While in reverse on flat ground everything is ok.
while in reverse backin uphill, or giving it gas the engine hesitates,
i.e = hold down brake while in reverse - 1,500 rpms and up acts like a rev-limiter, no power, rpms flutter up & down to 900 to 1500
-has trans fluid
-motor mounts ok
-grounds good, clean
-relays good
-full tank of gas
-no vaccum leaks
-
-thanks
-have a good weekend

X-J

any ideas ?

X-J

Problem solved-
Transmission to engine bolts loose causing CPS to misread flywheel because of the reverse torque separating bell housing from engine