'90 5.0 runs rough only when in gear???

[PaceFever79]

If it runs better with more initial advance that could still be a faulty sensor
not telling the computer to richen ... TPS, MAF, MAP, fuel pressure.

Personally, I think it is a lean bog. Need codes!

[Mark Aubele]

Find anything out yet?

[PaxtonShelby]

Check the vacuum hoses on the MAP tree. Revving in Park isn't torquing the motor over as much as when it is in gear and you're sitting there holding the brake pedal. You may have a badly cracked vacuum hose that opens when you put it in gear. A bad motor mount could make the problem even worse. Just a thought - but at least it would be a cheap fix. Good luck!

[White5.0]

Check the vacuum hoses on the MAP tree. You may have a badly cracked vacuum hose that opens when you put it in gear. A bad motor mount could make the problem even worse.

all vacuum lines are good, motor mounts are brand new.

also tried a mass air meter and distributor that are known to work properly (from my car) as well as new spark plugs. still does it.

I WILL get codes tomorrow...i've just been too busy lately. I got a job offer and had a bunch of stuff to take care of because of that. Ill get back at it tomorrow

right now my thoughts are that it is an electrical issue, sensor, or maybe something wrong with the tranny/torque convertor. but thats just my guess

[Mark Aubele]

Trans wouldn't make it do what you are describing.

[White5.0]

ended up being an electrical issue. forgot to hook up two grounds. got it fixed and it runs great now. Thanks for the help everyone!