1990 Olds Delta 88 Transmission Issues

[XGamesJ6]

I have a 1990 Oldsmobile Delta 88 Royale, and recently its been shifting and driving a little weird, like when I get up to about 45 it just starts to shake, and doesn't seem to want to go very well, and when I go to stop, or slow down, it'll shift down to first a little hard, i checked my service manual, and i personally think its the transmission vacuum modulator, if ANYONE could tell me if im on the right track, or what to look it THAT WOULD BE AWESOME!

[GTP Dad]

The vacuum modulator would be the place to start based on the symptoms you describe. They are not hard to change and are inexpensive.

[XGamesJ6]

then i'll start there, i'll buy the part today, and change it soon

[maxwedge]

This shaking and percieved loss of power doesn't sound like vacuum modulator symptoms, this usually generates late shifts, also there may be a tv cable on the 90, I think 91 was the first electronic trans.

[imgoofy76]

My daughter has a 89 Olds Delta 88 that has transmission problems. When you take off in drive it does not shift up even when you get going 40 or 50 miles an hour. What could cause this sort of issue? Would this have to do with vacuum or a modulator valve?

[XGamesJ6]

As an update to what i did, I replaced the modulator, didnt notice too much of a difference, the TV cable was adjusted right. I later found out the MAF sensor was bad, it was causing the tranny to shift in and out of overdrive while cruising at about 45 MPH. the check engine light was always on, but it was for a MAT sensor, one we replaced the MAF sensor, the light went off, and everything was working fine!

[maxwedge]

Wow 2 and 1/2 years later! Ok thread is way old now, thanks for the reply though.