The best hour of my transmission's life

[gcurtis]

Changed the tach sensor and viola, everything works smooth. Trans shifts politely, tach works... the world is fine.

Then it starts hard shifting again and the OD light starts flashing, but the tach still works.

What type of reader does a 1994 F250 IDI require? What other sensors are in the loop to cause issues with the trans?

[pnose]

The vss(vechile speed sensor) sens in the rear end pumpkin.FIPL(fuel injector pump lever) on the side of the ip.Remove the plugs from the tranny,inspect for corrosion and clean as needed.

[Mr_Roboto]

You can get a reader at Wal-Mart. It states on the package that it doesn't work for 1994 diesels. It WILL work for 94 IDI's, but not 94 PSD's.

Did the tach NOT work before you changed the sensor?

[gcurtis]

What type of compliance is the 94 IDI computer(ODB II, ODB I etc)?

The tach wasn't fully functional (it would operate some of the time) prior to changing the sensor. I noticed when I pulled it out that the sensor was covered in oil, but didn't have a chance to check out how the sensor works (I was in a rush) to see if that was correct.

The tach now works perfectly but I'm back in emergency mode. I'm wondering if the next sensor in the circuit is bad and will buy a tester a pull codes.

I really need a factory service manual... Anyone have a good source?

[Casey_1]

[ QUOTE ]
What type of compliance is the 94 IDI computer(ODB II, ODB I etc)?

[/ QUOTE ]
It's OBD I.

[Mr_Roboto]

I'm going to suggest you disconnect your batteries to let the codes clear from the computer and start fresh from there. A half hour unhooked should do it.

[gcurtis]

I've reset codes once (when the sensor installed) and it ran great. I'll try it again, however...

[gcurtis]

Okay, did the long reset and it lasted about ten minutes. I'll pull codes manana. And the plug is where? Under the hood or something?

Anyone have a site with codes so I don't have to bother you all?

[OkieGringo]

[ QUOTE ]
Okay, did the long reset and it lasted about ten minutes. I'll pull codes manana. And the plug is where? Under the hood or something?

Anyone have a site with codes so I don't have to bother you all?

[/ QUOTE ]

The code reader comes with a book with the codes in it. Have you checked the FIPL/TPS voltage? It should be 1.1 vdc. There is also a relay near the code reader plug on the drivers side fender well that you might want to replace, about $12.00, get it when you buy the new FIPL($17.00) at autoparts store. Good luck, OkieG

[tow_driver]

Okie, hear you mention relay by the code plug WHAT is the relay for?
second thing are the FIPL availible at a parts store O'reily is big by you I think, but what about autozone. Reason was I was puchasing it thru the dealer quite expensive, quality any good theu the parts store.

[Mr_Roboto]

The "FIPL" sensor isn't anything special, it's a standard TPS that's used on some gasser applications also.

[gcurtis]

In doing some research (prolly wrong) it looks like a PCM relay and Trailer Tow relay are next to the plug, so at a whopping $4.99 I'm going to replace them both when doing the FIPL.

Hopefully tonight I'll be back to smooth shifting.

Hopefully.

[gcurtis]

Woohoo! Thanks to those that helped point me in the right direction AND the person that directed me to another site with saved articles, my trans now shifts like a pro.

Changed the tach sensor (tach wasn't working) and it shifted great for an hour.

Changed a couple of relays (tow and pcm) and the TPS (even though I'd already had the grey one) and used one of the previously mentioned articles to reset the voltage on the TPS... reset the computer and voila! My truck has manners yet again.

Thanks again, guys.

[Mr_Roboto]

Good deal. The vast majority of the problems with these transmissions is electronic...

[gcurtis]

Well, hell's bells, here we go again.

Freakin' truck is back in "safe" mode and shifting hard again after a day of working properly.

What next?