Transmission shifting odd

Hey guys,
I have a 1994 f250 factory turbo with an automatic transmission. I was coming back from vacation this past weekend and the truck started shifting wierd. I can be cruising at 50 mph on a flat road not towing anything and the rpms will go up 200-300 then come back down....then go back up then come back down, etc.. Also the same thing happened at 70mph, I would see the rpm go up (I could also hear the engine speed increase) while holding the gas pedal steady. Also something else that I noticed is that the truck takes forever to down shift. I have to pretty much floor the truck to get it to down shift. My truck has about 170k on it and the transmission has already been rebuilt once. What should I be checking? Thanks for any advice.

I would start with fluid level and tps voltage.

Could be the torque convertor locking and unlocking on its own. Check the wires on the side of the tranny, I know on my truck its the P/Y wire that controls the convertor.

Thanks guys. I will check everything listed in the posts. Like I said it's a wierd problem. It does not really feel like the transmission is "slipping". Do you know the voltage readings I sould be seeing when the throttle is closed and then when I am a WOT?

I should probably also mention that while on vacation I was driving on the beach and it got pretty bumpy a few times so I could have jarred something loose or pinched/broken something. The problem that I am having was not apparent on my way to the beach but it was very obvious on my way back from the beach (7 day time frame)

The tech article says 1.2v at idle / 4.5v WOT. The sweep should be smooth. I found that mine likes higher volts. Mine is set at 1.9v idle. It sounds like you knocked something loose. Try unplugging the mlps and solenoid plugs, clean, apply contact grease and plug them back in. It could also be sand/water in one of the plugs.

homelessduck said:

The tech article says 1.2v at idle / 4.5v WOT. The sweep should be smooth. I found that mine likes higher volts. Mine is set at 1.9v idle. It sounds like you knocked something loose. Try unplugging the mlps and solenoid plugs, clean, apply contact grease and plug them back in. It could also be sand/water in one of the plugs.

Click to expand...

What are the MLPS and solenoid plugs?

Mlps plug is on the driver side of the transmission. The solenoid plug is on the passenger side of the transmission.

MLPS - Manual Lever Position Sensor.

About 15 years ago my E4OD trans was doing this same thing. I went to three differant Ford dealerships getting help. One told me the trans was shot to hell... Yeah sure. The next one said the tps was bad and two days later they installed a new one... $198.00 and the trans still acted the same. The next dealer said the trans computer (cpu) was shot so $600.00 and they installed a new modified cpu. Still same problem. So I bought a Jaspers trans and had it installed. That was $1800.00 for the trans and another $300.00 to install it.... Same problem still... You bet I'm mad a hell by this time. I find a guy in Phenoix thru ALLDATA that tells me the tps is shot so I drive all that ways to have him install one... Overnite stay and driving 80 mph all is fine... then its doing the same thing.... Can we all say fu this mess...... Sure can... Then I post all this on tds and a member tells me to clean the 6 electrical plugs to the trans. He tells me where they are located under the master cylinder. The other 3 are on both sides of the trans. clean them with contact cleaner thats harmless to plastic. Let dry and pack them with die-electric grease... So another $6.00 and you guessed it.. Problem solved... I'm all happy... Till I get a responce from Detroit about what these three factory trained dealerships did to me and charged me... They told me I had no case for any money back and if I had continued to return to the SAME dealer I MIGHT have had something due me... I have never taken my rig into a dealer since plus.. Two of those dealers are out of business... Charma is a ***** sometimes. These electrical connection get corrosion in them and they stop the current flow. Then the trans does all kninds of crap. The main plug found on the passenger side of the tran behind the heat shield must have that shield reinstalled or the exhaust line heat will melt it. Best of luck with this issue and I hope this helps you out. It sure was good for me after spending the farm only to get free advice from a idi forum...

^ Thanks for the advice. I will try that too. What's a good example of a "Contact" cleaner???? Thanks.

No contact cleaner is any better than any other in my oppinion. Just make sure its harmless to plastic.. Or your plugs are going to melt when you spray it on them. Use a tooth brush to get into the tiny places in each side of the plugs. Nothing with metal in it because you may short out the hot contacts in the plugs. Now if all you have is wire bruches please disconnect both positives on the batteries.

icanfixall said:

No contact cleaner is any better than any other in my oppinion. Just make sure its harmless to plastic.. Or your plugs are going to melt when you spray it on them. Use a tooth brush to get into the tiny places in each side of the plugs. Nothing with metal in it because you may short out the hot contacts in the plugs. Now if all you have is wire bruches please disconnect both positives on the batteries.

Click to expand...

Gotcha....I guess what I am saying I don't know what is considered to be a contact cleaner. For example.....brake parts claner? MAF cleaner? Carb and Choke???? I'll google it, but I am not quite sure what you are talking about....sorry for the dumbness


*edit* How about this??? I am trying to find something I can pick up on my way home at the local advance auto

http://shop.advanceautoparts.com/we...-spirits_1770051-p?searchTerm=contact+cleaner



**double edit**
I think this is the best one I have found....what do you think??
http://shop.advanceautoparts.com/we...r-crc_7070074-p?searchTerm=electrical+cleaner

Electrical contact cleaner, electric tool and motor cleaner. Any parts store should have it

Just read the lable and make sure it wont harm plastic. CRC makes several differant kinds of contact cleaner so please read the lable.