95 7.3 Check Engine Light and Dead Accelerator

[Freebird]

Engine will start fine and idle great but go and try to give it gas and the check engine light will come on and the accelerator pedal will be dead.

The Check Engine light will not come on until I start to give it gas. Then after a few tries I can get it go actually go somewhere but then it will come up again with the check engine light and dead pedal.

I know I have a vacuum leak and need to replace my belt driven brake booster because the brake light will come on at times because of this. Don' know if they are related or if anyone has any ideas on if it is a sensor or something else? Any help would be greatly appreciated. Thanks so much!

[englewoodcowboy]

You need to get a code reader and see what codes are coming up. A dead pedal is indicitive of the limp mode. It could be something as simple as the TPS but only retrieving the code will confirm the fault.

[Freebird]

Thanks, what is a good code reader to get. I have seen really expensive ones and really cheap one's are there any decent ones that will not break the bank? TPS is the throttle position sensor I am assuming correct? Thanks for the help!

[englewoodcowboy]

Most local part stores will read it for free if you can get it to one. If not, see if a friend has a superchips tuner, they will read codes as well. And you are correct, TPS is Throttle Position Sensor and if the computer can't see where it is, it will not allow you to apply throttle.

[Freebird]

Awesome! Thanks so much for the help. I sure hope it is that simple. Is the TPS located inside on the Gas Pedal assembly itself then or somewhere else. Thanks once again!

[englewoodcowboy]

I am not certain on an OBS truck. I would assume it is throttle by wire like all of the electronic injected engines but I could be wrong. If it is, I think it will be on the pedal assembly. In all reality there are not many sensors on the 7.3 that are necessary to make it run. It could also be the cam position sensor but again, a code retrieval will narrow your search greatly.

[Freebird]

Awesome! Thanks for the quick replies. I know I replaced the CPS about 4 years ago it was causing the truck to be sitting at an idle and then just randomly die. I know that was a quick and easy fix so I bet you are correct in assuming TPS. Thanks for all the help, much appreciated!!!

[madpogue]

There is no throttle on a diesel engine. The pedal position sensor is on the pedal. There's no cable because there's nothing to mechanically control. There is also an idle validation switch which should close with minimal pedal movement. The engine will stay at idle until that switch closes, even if the position sensor shows movement. The CE light is probably the PCM detecting pedal movement in the position sensor, but the idle switch still being open.

You can measure the position sensor resistance and the idle switch continuity with an ohmmeter if you can't get a scanner on it to read them as "data". Idle switch is very easy - it should read open / infinite resistance with the pedal at rest, and closed / continuity with a little pedal pressure.

[englewoodcowboy]

See there, didn't even know there were two sensors on the pedal assembly. Let us know what you find out.

Good luck!

[Freebird]

Great! Thank you for all the help and info!