Hello all
I bought a 1986 F250 2wd 6.9 liter about a month and a half ago from a mechanic. Supposedly, the engine and the front end was rebuilt that's why I bought it on impulse. The truck was running great until about 2 weeks ago when I left it sitting for 2 days. It started after so many pedal pumps. Well, after that incident it started to run worse like idle fluctuates, engine dies and started sputtering. So I went into the internet and found this awesome site and noticed a lot of similar problems my truck is experiencing. I ordered me a set of injector install kit from DIS and installed it today. Purged the air from the schrader valve on top of the filter housing and the truck was purring like a kitten. I have a good mechanical background but this is the first diesel for me. Few reasons why I went to diesel are no smog in California and fuel is cheaper. Anyways, I'd like to know any more problem areas that I should look for. Probably going for an electric fuel pump and bypass the mechanical one in the near future. Also thinking about putting airbags because I'm basically loading a lot of heavy stuff in the bed. I have one problem that I can live with but needs to be addressed. When I stomp on the pedal and release my foot quickly, engine dies. Slowly ease on the pedal, idle's great. What do you think's the problem?
Thanks

Willie V.
1986 Ford F250 lariat 6.9L diesel

 

If your not using an additive in your fuel,then get some in there,it may correct that prob.Pumping the pedal does nothing to help a diesel start.Hold it about 1/2 way till it fires up and then release.A lot of guys just give it one pump after turning on the key to set the fast idle solenoid,then fire it up.How many miles on your injection pump,dying when releasing can be an early sign of pump failure,usually followed by hard starting when hot.

 

That's the dreaded flex ring in your (injection) pump going bad. Start saving your pennies for a new one.

 

I have a question is this the part I was told would have to be sleeved if it was bad ? Don't have any major pump issues just a leak and a bad a$$ed diesel smell if you walk around truck after or while its running, see a small leak coming from under the pump.I was told the damn thing was leaking internally?? Truck runs to good to pull but would like to address this issue soon!! Am on the fence wanna fix this and add turbo maybe in the future really hate to trade this pump in for fear of getting a peice of #@$%& have heard some horror stories !

 

The sleeve is the dreaded 7.3 problem. That's what you have to do to one of the rear cylinders if it pinholes through to the water jacket. Shouldn't be a problem on your 6.9, they had thicker cylinder walls.

I know all about pump horror stories. Unfortunately you live in just the place that puts out many bum pumps. We had one from some big injection place in TX, it did things new that I've never seen in an old wore out pump. You may want to order out of state to be sure.

 

Thanks for the replies. I think I fixed the problem accidentally. On top of the Injection pump there's a plastic valve and it looks like two vacuum lines going in. I might have disturbed the valve while working on the return lines because it wasn't seated all the way in. I pushed the valve in and checked the vacuum lines and alas! no more stalling. Anyways, I'll take a closer look at the injection pump but so far so good.
Thanks

Willie V
1986 Ford F250 2wd 6.9L diesel

 

Desert Diesel in Tucson AZ was our preferred choice years ago. They had competitive prices and they always did a top notch job. If we had any problems, they would fix it no questions asked.

 

Thanks for reply, I found a person thru a freid who said he could pull my pump down and reseal it , he works in the pump shop at the local international house! This guy is supposed to be a whiz at these little pumps we shall see ! Just need the little leak fixed , as far as the pumps ops. it seems to work well as everyone tells me the darn truck runs bad to the bone for being n/a!Have to put the bigger exhaust on next just waitin on my buddy to produce his stock PS tail pipe and stuff gettin real darned inpatiant!!

 

That plastic valve is just for the modulator valve on the back of your tranny. It won't effect how it runs, just how it shifts.