Hey guys, I have an '89 F-150, 5.0 aod. I have a suspicion that the TPS is going bad. Is it possible that it could cause the transmission to shift horribly? When the truck is driven with a light foot around town, it shifts ok for the most part but if you have to get on it like your getting out into traffic then it'll act up and keep 2nd up to about 47 mph- even if you completely let off on the gas it'll act as though it's in neutral. Any suggestions are very much appreciated. Thank you!
Scott

 

Scott ,
Id be more suspicious of a problem with the transmission rather than the TPS Sensor . You can always check for any stored fault codes ...What trans is in your truck ? Any other driveability problems ?
Paul

 

Paul, I have the AOD tranny. I'm suspicious of the TPS because the "check engine light" comes on when on the gas. When coasting or just maintaining road speed the light stops flashing. The truck has very poor acceleration and gas mileage. Of course I do need to check or replace all general tune-up items. My '83 Toyota has far better acceleration! It also acts as if it is cutting out while driving at any speed. I did remove the throttle body and gave it a good cleaning and gave it a new K&N filter. The truck is bone stock with 3:55 gears and 4wd. I really need better all around performance. Thanks for your suggestions!
Scott

 

Paul, I have the AOD tranny. I'm suspicious of the TPS because the "check engine light" comes on when on the gas. When coasting or just maintaining road speed the light stops flashing. The truck has very poor acceleration and gas mileage. Of course I do need to check or replace all general tune-up items. My '83 Toyota has far better acceleration! It also acts as if it is cutting out while driving at any speed. I did remove the throttle body and gave it a good cleaning and gave it a new K&N filter. The truck is bone stock with 3:55 gears and 4wd. I really need better all around performance. Thanks for your suggestions!
Scott

 

 

Scott, I have the exact truck you have, for a farm truck. I have 145k now, and am not having any tranny problems yet, knock on wood. I agree with Paul, if your having shift problems, it would be with the tranny. The Aod is a non-electronic tranny, it gets shift points from vacuum? I have heard that the AOD shifts from 2-4th in od, and 2-3rd in D. Does it help if you drive around in just D? I recently had my fluid replaced and all the fluid in the convertor. It made the shifts a little more often, and smoother.


Pastmaster's 1993 XLT 5.0 E40d 3.55LS Normal Cab/Long bed Loaded from the factory with aid of...MSd 6a ign/s.p. wires, blaster coil, Hypertech Chip, K&N filtercharger, Cat-back dual exhuast w/o mufflers, 3.5", echo tips, Accel distributor cap, Dark Mocha over light mocha. 5% Dark tint, Alpine Cd player/remote, Pioneer speakers.

 

I drive the truck in D unless I'm on the freeway, then OD. It clunks loudly when it shifts to 4th. I'm going to change out the u-joints and see if that helps. The truck has 117k on it and is just plain gutless! What are the chances of changing to an E4OD succesfully? I'm gonna change the tranny fluid including whats in the convertor and see if that helps. Thanks again.
Scott

 

Scott ,
The best thing to do is retrieve the codes from the computer , follow the diagnostic routine once you have any EEC codes and go from there . You can retreive the codes with a simple jumper wire using the Check engine light flashing the codes . If you arent familar with this , Id suggest getting a DIY manual like Chiltons and any thing you dont understand or need help with , post back & Im sure one of us can walk you thru it .
Paul

 

Thanks Paul, I'll look in to that this weekend. I've never checked codes before and I dont't know how or where to do this from but I'll get out my Haynes and read up on it.
Scot