I have a 91 F150 4x4 351 E4OD. Last night on my way home from a friends in the country my truck suddenly accelerated while I was doing about 55mph. It only did it for a few seconds but is still very concerning and this happened two times on the trip home. On the way out to my friends it did the opposite with just a light stalling but only one time. Does anybody have an idea of where I should even start to figure this problem out?

 

There's a chance it has so something to do with the TPS so pull the codes first and make repairs if necessary, but if that comes up clear then start looking for mechanical things like a sticking throttle cable or heavily warn throttle linkage on the TB.

 

I will try to pull codes tomorrow. All other suggestions are still very useful to me. Thank you for your help.

 

Don't let your "trunk monkey" ride under the hood where he can reach the throttle cable!!!!!!

 

My truck is also having hard 1st to 2nd shifts once it gets warmed up. Could this also mean it might just be the TPS?

 

Yes, these two conditions could be related, and it isn't the first time I read about hard shifts when the TPS is failing.

 

My check engine light is not on now but I know it works. Will there still be a code stored if the TPS is faulty?

 

Did you have the cruise control on? There is nothing mechanical that can make the truck accellerate outside of that.

 

No the cruise control was not on. Now that I think about it bout a year ago I was driving with it on and it did accelerate once so I just quit using it. Could this be the cause if it wasn't even on?

 

Ran codes today came up with 13 and 72. Does anybody know what these are and if they could lead to my problem?

 

It looks like your codes are for operator error....

http://www.troublecodes.net/Ford/

 

It could also be the IAC. That was the culprit for that problem in our explorer and out old jeep.

 

The IAC should only affect the idle of the truck, I personally wouldn't consider it initially.

 

Doubtful but you can just disconnect the cable from the C/C unit where it attaches to the throttle if you want to eliminate that as a possibility.

 

Those are Codes from the Key On Engine Running tests, which are operator induced. You should start with the Key On Engine Off (KOEO) tests and Continuous Memory (CM) display.