Ford 6.9 missing and stumbling around - need advice

[Blakers]

My dad's 87 one ton dump has a 6. 9 IH engine that only has 105,000 miles, no blowby and uses almost no oil. About a week ago it started missing. It's lost power and the engine shakes a little at idle, but it doesn't seem to be one particular cylinder. Loosening the injector lines one at a time makes each cylinder to cut out. So the miss seems to be moving around and not one bad one.



Any ideas? Is the pump shot?



Where's the cheapest place to buy injectors or a pump for these?



Thanks,

 

[bmoeller]

Probably the inj. pump. From what I've read/heard they are good for about 100k. Check the supply pump also. When I put in new Head gaskets at 129K on mine, I put in a new supply pump since it was easy to get too that way. The pumps lever arm was really worn and moved up and down with very little resistance. The new one one is alot stiffer. Make sure the cam is in the correct position so the the arm hits in the right spot.



While you have the lines off the inj. pump, may want to consider new injectors, somewhere around $25 each.



As far as new/rebuilt parts, DIS has really good prices. http://www.dieselpage.com/fuel.htm

 

[Blakers]

How hard is it to replace the injector pumps on these? Do they have to be retimed or is there a way to keep the timing in place?



Thanks.

 

[Scot]

Swapping the pump is pretty easy. The gear is keyed on the shaft. Just pull the oil fill spout for access. Remove the lines at the injectors. Remove the fuel inlet. The whole mess comes out and remove the lines later.

 

[Blakers]

So you can't mess up the timing? I presume there's timing marks on the gears.



Thanks.

 

[Evan A. Beck]

I've done a bunch of 6. 9/7. 3 injection pumps... Don't worry about being precise with the timing. There are marks on the pump and gear case, so just line them up when you stick the new pump on.



Whenever I change a pump, I always follow these rules:



--Replace injectors

--Replace fuel return lines

--Replace fuel filter



Doing all these things at the same time is a must. The injection pump will only work as good as the injectors are. Injectors are cheap, and be sure to get NEW ones, not reman. The reman ones are junk--I found that out the hard way. Any good fuel injection shop will have the pump, injectors, and installation kit. The installation kit is made by Dipaco Diesel Parts. It includes all the hose, fittings, and clamps for replacing injectors and return lines.

 

[Blakers]

What pressure should the diaphragm lift pump be putting out on these engines? Will checking that pressure tell whether or not the lift pump is any good?



Thanks.

 

[big jake 1]

a lot of us guys who run





THE FIRE -BREATHING 6. 9s





have also converted to an electric lift pump as the standard fuel pump looks pretty cheesy, I found evidence of an exploded manual lift pump in my oil pan when it was down for rebuild ( springs and a lift arm)



I replaced it with a NEW FORD fuel pump during my engine rebuild, it lasted 150 miles and spit its guts into my oil pan where they reside to this day, I tried running Holley Red electric pumps @ $110 a piece and burned up three in less than 18 months, I now run a cheapie universal pump from autozone for $ 39 for the past 2 and ahalf years, no problems.



all the fuel I need , no starvation problems.



make sure the system is tight with no leaking return lines, the electric pump will help you find these problems once you pressurize the fuel system





good luck



big jake THE FORD GUY... .....

 

[Evan A. Beck]

Originally posted by Blakers

What pressure should the diaphragm lift pump be putting out on these engines?

Four to five psi at idle is typical.