Engine will not rev when accelerator is pressed

[YellowHorse]

My '96 F350 7.3 Auto PSD that is having a problem with acceleration. This problem is connected to the outside temperature and came about suddenly one morning about a week ago. I have an idea as to what it might be, but wanted to put this up and see what answers I get.

If the temp outside is below 70, the engine will not rev when I press the accelerator, just the check engine light will come on. I release the accelerator and the check engine light goes off.
At about 75 - 85 degrees, the engine will accelerate, but will catch unexpectedly and almost feels like the tranny is slipping, the E-brake and ABS lights will be on and occasionally the check engine light will light up too.
About 90+ degrees the truck runs like nothing is wrong, no lights come on, and runs smooth and strong.

This problem will not improve as the engine warms up, it is completely dependent on the outside temperature.

So, any ideas?

[madpogue]

Never heard of this related to temperature, but this sounds like an issue with the go-pedal. Remember, this is a drive-by-wire truck; the pedal is just a big "volume control" variable resister. It's often called the Throttle Position Sensor (TPS), but it's really a Pedal Position Sensor. There's also a switch that opens and closes at the idle position. If you're getting absolutely no response from the pedal, that suggests that either the idle switch (IVS) or position sensor (TPS/PPS). You might find a complete replacement pedal assembly, with both electric components included, at a junkyard or the classifieds section of this or one of the other Powerstroke sites.

'Course, this doesn't explain the brake warning lights. When this happens, do you happen to notice the speedometer jumping up or down?

Just so we're all on the same page, does this happen even in Park (if automatic) or Neutral?

BTW, the red "BRAKE (!)" light is NOT just an "e-brake" light. That's a rather minor use of the light. It's major purpose is to light up when you have a brake hydraulic issue, like low brake fluid level or pressure. IOW, if it lights up while you're underway, you may have no brakes.