Hi all,

This is my first post on the FTE forums, so please bear with me. I am inhereting a 1994 Ford F-150 Supercab, with an 8 foot bed. The truck has electronic 4WD, Automatic Transmission, Fuel Injection, PS, PB, Air, 5.0 302 V8, and duel gas tanks. From what my father tells me, the truck has about 150K miles.

Its up in NJ, and I am down here in Philadelphia, and according to my dad, the truck isn't driveable for any great distance. He explains the problem like this:
"When starting out, the truck shifts from first to second fine. When it goes to shift from second to third, the engine starts to race and the truck loses all power."

He was able to take it to a local garage that's a block away from his house, and they put it on the computer 3 times and each time it came up "throttle sensor". The mechanic at the garage (this garage only does brakes, shocks, etc. - simple jobs) says that its probably the transmission and we should take it somewhere else (he recommended a place that's too far to drive to - it would need to be towed).

My question(s) is:

• Is anyone familiar with this problem based on my very brief description?
• What is the throttle sensor and could it be causing this problem?
• If it is the transmission, do they typically require a new or rebuilt transmission, or can they be repaired?
• What does that type of work cost in general?
• If it is the transmission, is it worth fixing with 150K miles on it?

Just a little more background info: the truck is otherwise in great shape. The body is great, the engine runs good, and all recommend maintenance has been performed in a timely manner. I plan on using the truck for short local trips, occassionally going 200 miles round trip about 1 time per month (on the highway). I won't be towing or hauling heavy cargo - I just want to use it to get my dog and all my training equipment to the training fields.

I appreciate any general insight anybody can offer!

Thanks!

 

Throttle sensor is probably "throttle position sensor" aka TPS. Very common for them to have dead spots, to generate codes on a self-test, easy and cheap to replace. But this is unlikely to cause the transmission symptoms noted.

The E40D transmission in early 90's trucks has had many issues. It should have been strong design (based loosely on the C6), but reality turned out differently. At 150K miles, the actual service life for this trans wasn't so bad and a rebuild should not be resented that much.

Failure to make the 2-3 shift could be a problem with the shift solenoids in the trans. These are relatively inexpensive to replace and it can be done with the trans still in the vehicle. Somebody with more knowledge than I have might chime in and validate or repudiate this possibility.

It could also be a problem with the wiring between the PCM and the transmission. But in this case the computer should be flagging a "SS2 circuit failure" or something like it.

Or there could be mechanical wear/damage in the trans requiring a removal and replacement with a rebuilt unit.

If it were me, I'd drop the transmission pan and look for bits of metal and other obvious signs of internal damage. If you find "1/2 pound of ground round" in the trans oil, you know you are facing a rebuild and can decide if you want to invest that much in the truck. If it looks OK, there is the possibility of a cheaper fix and you can decide to invest in the tow to the trans shop.

You could probably have your Dad take the truck to the local garage and have them do this much, trading a $70 or so investment instead of you driving up there.

 

Congratulations on the new truck.

There is a transmission forum here and you should probably post your question over there. There is a good chance that this started as a control problem with the solenoids, etc. If the truck was driven after it started malfunctioning the the trans could be destroyed.

Finding someone that will deal honestly with you on this is the big problem. Many transmission shops are run by crooks and they will probably want to charge you for a rebuild even if they can fix the trans without removing it.

A company called ATSG prints service manuals for automatic transmissions. If you are going to try to fix this yourself, I would start with some good manuals. You may want to read up on it just so you can talk to the mechanics and have an idea if they are being truthful with you.

The service manuals have troubleshooting flowcharts that you can use to test the transmission to see if it needs to be rebuilt.

Slipping is not good, the failsafe mode on a good transmission does not let it slip.

There are replacement transmissions available for around $900. Look on eBay for some more info.