I have gotten a service throotle soon twice while driveing. It seems to go into a limp mod for about 2 seconds then all is well? Can someone please advise what to do? This is a 1996 GM 6.5 1 ton diesel.

rcreel, it would be a wild stab at this without the codes but my guess would be the throttle position sensor or the (gas pedal). the gas pedal has a rheostat on it to tell the computer to give the truck fuel. but before you go and spend (ka-ching) $300.00+ dollars on one i would pull the codes first and see what the problem really is. if you dont know how to pull the codes you can go to kennedy diesel.com and look under 6.5 litre tech tips and it will show you how. once you have the codes we can help you a lot better.

R Creel welcome to the site, we need a little more to work with, stroll to the FAQs locked above we have info on both OBDI & II, Autozone et als can read codes, won't know what to do with them, but FAQs & members here more than happy to assist.

also once you figure out how to navigate the site, go to the USER CP button far left in blue tool bar and update your sig for future reference helps us figure out what flavor 6.5 your truck is.

Look at the wiring and in specific the grounds off the app and the ecm harness to engine grounds.

Don't know where your from rcreel, but Autozone here in Ohio will not be able to read OBDI. I found this out the hard way. They refused to do the paperclip reading for legal reasons. I have seen no harm in it since it has been done on my truck and I don't think the problems I had where from a code reading.
I will not try to advise you on how to do the paperclip reading since I am new to it myself but I need to learn since the stealer can "KMA" before I spend $70.00 for them to plug something in for 5 minutes(ok I'm a tighta**). But I still think that is ridiculous.
There are several people on this site that can tell you how to use the paperclip jumped between pins "A" & "B" on your reader board under the dash on the "R" of the steering wheel. I have not understood a clear definition of how to read the different pulses/blinks due to the differences in vehicle years. They each do something different.
Hope this helps.
Mark

correction: I just read back and you have a 96. You should be set on OBDII and any autoparts store that has a reader, should be able to do it for free.
Sorry for speaking out of context earlier.

Mark in FAQs OBDI code list QM IIRC posted pics how to clip it & read them, OBDII takes a reader but Autozone & others should have a tool to pull them but most can't reset the code, some codes self reset once the problem is cleared after x # of successful code free starts.

Kimagine,

Since you are OBDI all you have to do to clear the codes is press the brake and throttle to the floor for a couple seconds while you are jumpered. The codes will clear when you turn the key off and remove the jumper. If you reinstall the jumper after this operation and they cleared, you should only get code 12 to indicate things are working fine.

rcreel, I agree with bowtie65. Check the codes as some others have suggested but my suspicion is the sending unit for the accelerator pedal. Had ours replaced on warranty at one year old (back in 96' or so). It is a possibility.