I have a 94 chevrolet dually 6.5, this started yesterday. At first when I started it after work it was idling rough, when I got to the end of the road it would start jumping from 1500-2500 rpms when my foot was off the gas. Then drop to about 1000 when I put my foot on the gas. I shut the truck off and started it back up and went straight to about 6000 rpms and I shut the truck off. I got the truck home and started it avian today and it did the same thing. Any ideas on what the problem could be?

 

Is the check engine light on if so what are the codes

 

No the check engine light doesn't come on.

 

The check engine light did come on yesterday and gave me the code for the pmd. I had just changed it out recently and was still under warranty. So I replaced it again. I also replaced the lift pump recently. It is still doing the same thing though.

 

What code are you getting ?. PMD 99% time don't set off a code

 

It was 6-3.

 

If it code DTC 63 - Accelerator Pedal Position 3 Circuit High

Check the plug at the pedal make it clean and plug in tight and all so check grounds really good

 

I cleaned the plug and made sure it was plugged in good. Then I tried starting it and wouldn't crank. I checked the codes again and got 13, 16, & 49. I see that 13 is engine shutoff solenoid circuit fault. 16 is vss buffer fault, & 49 is service throttle soon lamp fault. What should I do to resolve these issues?

 

I would start with the cheapest repair first. The codes sound relevant to the issues you are having.

 

Thanks for the info. I changed the shutoff solenoid. That didn't work. I'm still getting the high rpms when I start it and then it idles down and jumps high to low. I just don't know what would make it do that.

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Another thing is service throttl light has come on. Could that be my problem with it reving up like that?