1989 T-Bird (not SC, unfortunately)
Here's the problem:
Car has no power at highway speeds. It was missing badly at all
speeds a couple weeks ago. Since then I've replaced the following:
Cleaned the throttle body.
I've also set the timing to 10 DBTC (yes, with the SPOUT
disconnected.) It was off by 3 degrees fast, which really should have
been okay anyway.
Everything I've done has improved the running condition of the car, so
I'm sure it all needed replaced anyway, but I'm still having problems.
To be more specific, I can accelerate to 50-60 okay. There's a little
roughness on the way there, but not bad enough to hinder the car's
performance very much. The problem is most apparent after the car
shifts to 4th gear (OD). If I give the car just a little gas, like
you would do to accelerate gently or to maintain speed up a hill, it
just sputters and won't actually accelerate significantly until I give
it a lot of gas, usually enough to make it downshift, even then the
car shakes while it's accelerating.
I should note that the car idles fine and revs smoothly in Park.
I'm going to buy some Techron treatment as WalMart today. Maybe
that'll help. Probably not, but it certainly it can't hurt. What
else could I be looking at? Throttle position sensor? MAP sensor?
Any ideas? Anyone? Please?
My husband is as stumped as I am :(