Diesel Runaway problems

throttle position sensor if it has one

Originally Posted by lousypirate

Originally Posted by MattInTheHat

throttle position sensor if it has one

TPS only controls the point at which the trans shifts into OD and torque converter lockup.

On my 24v it controls throttle from idle to WOT. It kept giving me dead pedal. Would get into an intersection, start my turn then just no power. Dead pedal. Was fun times.

I'm not trying to be funny, but it's winter time, it's possible frozen moisture in your throttle cable and it's staying in the same position for a moment after removing your foot from the throttle. I'd try some wd-40 before I tore into that pump

Edit:
Also make sure that tension spring isn't broken

It might be worth pulling a boot off to see just how oily it is inside the intake tract. I don't know if the 12V had a allen head threaded plug on the bottom of the intercooler or not, but if it does, pull it out and see if oil comes out, a "little bit" is alright but not ALOT. If you do find a significant amount of oil then the center cartridge on your turbo needs to be rebuilt. Just because it doesn't look oily from the air intake side means nothing.

Alternatively, an injector with a stuck poppet can cause your engine to run up, but it'll do it CHUGGING sounding like an old two cylinder john deere and not a smooth run up at all. If it is the rack sticking, there's a few things you can do. One is because we run ULSD now (thank you government...) that the diesel additives from the pump just arent enough for older diesels. Try a quart of regular old dexron atf with your next fill up right in the fuel tank, do it for several fill ups in a row. After the second fill up your sticking problems should be gone. Still want to run it for one more tank afte that. Caveat, the truck might have a "slight" haze to the exhaust but I doubt it'll be noticeable to you.

I fix these things for a living, and those are your low buck cheap tricks to try before I suggest you take things apart and I show you diagrams of what to look for that might be broken.

Also, if you determine it is the pump, you can stuff it in a box and ship it to me, I rebuild them for 300 without new delivery valves and 550 with new valves, rack plug, pressure spring and a fuel plate of your choice.

also make absolutely sure you have no air in any fuel lines, air trapped in the injection lines or pump can make for very erratic rpm spikes and stumbles (i.e. you press the throttle and nothing happens....nothing happens....you release throttle think WTf is goin on?....still nothing happens, -- then wham! your running at 3000 rpm and it wont idle down til the air pocket is pushed through the system, scary as h@** when your driving through through town and this happens)

air in the system is also one of the most common causes for hard starts / restarts.

air in the system is also one of the most common causes for hard restarts.

That was a quick learning experience for me with a Chevy diesel I had bought not too much earlier. The injector pump started leaking around the throttle shaft. Leaking a little fuel and sucking a lot of air. To get it to start easier I would crack open an injector line at the motor and crank the motor till it started. Finally cost me a rebuild pump and another starter from cranking too long at a time. I loved to hate that lil 6.2.