Maybe you guys can help with my 89 T-Bird?

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:
Plugs Wires Cap Rotor Ignition Coil 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 :(
Thank you!
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JK wrote:

Sounds like a fuel filter to me. I would change that as well as use the techron. el lobo
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wrote:

But wouldn't a clogged fuel filter cause it to run rough regardless of speed?
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On 25 Jul 2003 01:32:36 -0700, snipped-for-privacy@wt.net (Mark Keith) wrote:

Thanks MK. Not sure how to do all of what you suggested, but I'll certainly figure it out. Thanks again.
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If you don't have one, a good shop manual will help. The Popular Mechanics CD's that you can get at AutoZone are OK and there are a couple of OK paper ones, too. The best would be the Ford factory manual but I doubt you can get then anymore. They cost a bunch, too.
Paul in Ohio
(Mark Keith) wrote:

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(Mark Keith) wrote:

You'll need an attachment to hook up the fuel pressure gauge. Not sure what ford uses. Toyota uses banjo fittings. Ford may use something different. I think these days, you can buy prefitted gauges and hoses at most auto parts. You can check the pump by running the hose to the fuel rail to a gas can. Should do a certain volume per seconds run. You will need a manual for sure, as the methods of testing and the specs will vary from car to car. Most of the larger Haynes and chilton manuals will be good enough. MK
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JK wrote:

You bet! Let us know what the problem was.
--
el lobo


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JK
Check out the Thunderbird Cougar Club of America web site at www.tccoa.com for some answers to your problem. A good source of information.
Desert Guy
*******************

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