stangsbs5150

I have a 89 cummins that I tried running with cooking oil. I had problems with it so I quick using it. I've cleaned the tank, changed the filter and added injector cleaner. I can start it and it will idle all day. As soon as I take off, it dies in about 2 miles. Let it sit for a while and shoot a little starting fluid and off we go for another 2 miles. Not sure if it's a vacuum problem or cooking oil issue. Any thoughts would be appreciated.

Diesel Dave2

I wonder if your injectors got coked up...and the cleaner couldn't get them clean...Just a idea..

stangsbs5150

That's what I've been thinkin but wasn't sure with it idling fine. How tough is it to take the injectors out? My first thought was to pull them and clean them and go from there.

patdaly

The 2 miles it drives, does it run OK? Do the first gens have the same fuel heater/pre-filter that the 12V 2nd gens do? If so, did you clean the pre-filter?

It almost sounds like something is preventing it from getting enough fuel to keep running. Could something be plugging up teh return system?

j-fox

Screen in the tank is plugged. Biocide MAY clear it.

stangsbs5150

I assumed it was caused by the fuel/cooking oil. I didn't drive it for 10 years and it fired right up. Then I tried runnin cookin oil and problems started. Since I hadn't drove it so long I thought it could possibly be bad vacuum hoses. I might try and put a little sea foam in it and see what happens, then take the injectors out. It runs perfect for the two miles. Then bogs down, will continue to run but jugs along real slow.

Santaclaus

Ive been told that most biofuels will clean your fuel system very quickly, it is generally recommended that you carry several extra fuel filters for that reason. And since you're a truck has been sitting for so long I was imagining it is full of gum.
You might go on the engine and driveline section of this board to find out how to diagnose your fuel system.
Mike

patdaly

Bet you anything it is not the injectors.

You need to find the restriction in either fuel supply or return. Injectors would not wait for 2 miles to throttle it, and would not clear up for 2 more miles after a restart.

Start at the tank as Jfox said, and work your way forward, concentrating on the fuel supply to the pump and return from the pump.

stangsbs5150

OK thanks again, You guys are a ton of help. When I first started having problems, I would change the filter out and it would run with the fuel I had in the filter, I assumed, so it makes sense that it's something from there back.

stinkindiesel

10 years of sitting- and the diesel in the tank gathering moisture and turning to crud- then comes the WVO with all the beaks, feet and breadcrumbs... I'd bet the pickup sucks all that shmutz to the screen and chokes out. Then it drops off after it sits for a bit till you fire it up and start the process again.

BTW, straight/waste veggie oil is not the diesel sludge solvent that biodiesel is. Biodiesel will get your filler neck and tank shiney-clean inside; veggie oil won't.