85 IDI 6.9 runs rough after fuel decrease

[red_wing_bikes]

I am shotgun methoding this question. I posted on the Ford-Trucks/Dieselstop forums as well on Facebook and just thought I would post it here too just so I can hit as many smart people as I can. I will start this post by saying several things. I have never owned a diesel and I have never owned a truck. I love to learn but am only as good as what others are willing to teach/what is available on youtube. I am 34 and have been trying to play catch up and have only just now been trying to learn to be somewhat mechanical for the last couple of years.

I bought an 85 6.9 IDI Ford that ran great but had an engine oil cooler leak among other small problems. I fixed the oil cooler leak and did other various maintenance items and finally got to the point I wanted to make a fuel adjustment on the injection pump. The guy I bought it from indicated he had it "turned way up" and after a fill up I was getting 12mpg. With diesel prices what they are, I decided now was the time to get that turned back down. I asked him how far he turned it up. "Two full turns or so" he said. Not having done any looking or researching I simply followed a guide online on how to turn it back down (take plate off/turn engine until allen head visible/turn it counterclockwise), and turned it back down two full turns. Well after that dumb move (I realize now you need to make micro adjustments to these), it would not start. Cranked it enough that the batteries died. While charging I did a little research to learn that you can actually turn the fuel down enough that it won't even run. "Ok I must have turned it too far down" I thought. I turned it clockwise half a turn, still no run. Turned clockwise half a turn more, still no run. Finally decided 12mpg is going to be just fine and turned it back up to where it was. What I didn't realize was the previous owner had the allen head maxed out which made it easy for me to figure out how far to turn it back up since it stopped turning... Well it DOES start now but runs like a load of crap. If you give it too much pedal, it coughs and sputters and has no power. It actually will only can gain speed on flat ground/downhill. It also loses prime on shut off and needs to crank 15+ seconds to start. I was thinking maybe I just got unlucky and the lift pump died, I went ahead and replaced it. Still runs the same.

So my question is...
Did I mess up the pump calibration?
Is there a way to fix it if I did?
Do I need to adjust the timing on the pump?
Or does it simply sound like air intrusion/leaking somewhere?
Any help in directing me on the avenue I need to take next would be awesome.

 

[Brian VT]

I'm no expert but from what I've read/learned here:
- The pump (new or rebuilt) needs to come from a reputable source.
- You can get the timing set "by ear" well enough to run but you need a timing meter to get it done accurately.
- You can install the pump upside down if the timing gear? has been removed.
- Never run the engine when the IP bolts are not tight.

 

[IDIBRONCO]

You can install the pump upside down if the timing gear? has been removed.

No. You can get the gear to gear timing off. Even up to 180* out.
Red_wing_bikes, without being a pump expert, I'm thinking that it sounds like there was something wrong with the pump to cause the PO to turn it up all the way. You may be looking at a new pump here. If a pump is working fine and you turn the fuel adjustment all the way up, I think that fuel would practically (not literally) run out of the tail pipe. You would also be getting a HUGE amount of black smoke. I can see no reason to turn a pump all the way up unless you have a big turbo that can push enough air to burn all of that fuel.

 

[red_wing_bikes]

No. You can get the gear to gear timing off. Even up to 180* out.
Red_wing_bikes, without being a pump expert, I'm thinking that it sounds like there was something wrong with the pump to cause the PO to turn it up all the way. You may be looking at a new pump here. If a pump is working fine and you turn the fuel adjustment all the way up, I think that fuel would practically (not literally) run out of the tail pipe. You would also be getting a HUGE amount of black smoke. I can see no reason to turn a pump all the way up unless you have a big turbo that can push enough air to burn all of that fuel.

Appreciate the reply. Any recommendations on injection pump if so? How do you tell if the pump itself is bad? Crack the injector lines and see if they have good flow? It's interesting because this pump was installed around October of last year by the previous owner. His sheet just says "used injection pump $250" so I'm not sure what that means. It ran so well before I messed with it too lol

 

[Big Bart]

Red-wing some thoughts.
1) Sounds like your pump is used, not rebuilt. A rebuild is +$800.
2) This is the first I have heard of someone who maxed out a pump on a NA and was not rolling coal all day. Your supposed to turn a pump 1/6th (One flat. Which is one side of a hexagon. IE - One edge of a Allen key wrench.) of a turn at a time. Not a full turn. Likely he turned it up two flats not two turns.
3) So how do you recover now.
a) I would turn down 1 full turn and test. Then start to move it 2 flats at a time down from there. Once it runs, get to a point when it only rolls a little coal full throttle.
b) You likely have air in the system by now. (Opening up the pump.). So after you go down one turn, seal up the pump, then bleed the injector lines till you see diesel coming out. If you do not get diesel at the injectors lines and injectors, check your IP shut off solenoid. Make sure it is getting power. You may have bumped it and it is now not making a connection and not letting diesel to the injectors because the solenoid is not getting +12v from the ignition switch and batteries.
c) These trucks are sensitive to starter rpm. So charge your batteries 100% before trying to start it. If you are cracking slow it will struggle to start.
d) Make sure your glow plugs are working, no glow plugs, you will struggle. The block heater can be an alternative if the glow plugs are not working.

FYI if you have a 4.11 rear end, welcome to the 12mpg club! I have a C6 and a 4.11 and that is what I average. Want to get more MPH put a 3.55 and now you will get 15-16mph. (Maybe more if you have a velvet foot.). But you loose some towing power in the process.

None of the above works? Time to send it off to the pros to reset it or rebuild it. See the following tech article for vendors.

Where to go for injectors and injection pumps.

I wanted to post this since it is a weekly question “who/where do I go for injectors and injector pumps?” I believe this has been posted by vendor but not a list. Unlike a oil filter, ignition switch, or fan belt. Buying injectors and pumps at the auto parts stores or worse yet online have...

www.oilburners.net

Send some pics and keep us in the loop on progress.

 

[red_wing_bikes]

Red-wing some thoughts.
1) Sounds like your pump is used, not rebuilt. A rebuild is +$800.
2) This is the first I have heard of someone who maxed out a pump on a NA and was not rolling coal all day. Your supposed to turn a pump 1/6th (One flat. Which is one side of a hexagon. IE - One edge of a Allen key wrench.) of a turn at a time. Not a full turn. Likely he turned it up two flats not two turns.
3) So how do you recover now.
a) I would turn down 1 full turn and test. Then start to move it 2 flats at a time down from there. Once it runs, get to a point when it only rolls a little coal full throttle.
b) You likely have air in the system by now. (Opening up the pump.). So after you go down one turn, seal up the pump, then bleed the injector lines till you see diesel coming out. If you do not get diesel at the injectors lines and injectors, check your IP shut off solenoid. Make sure it is getting power. You may have bumped it and it is now not making a connection and not letting diesel to the injectors because the solenoid is not getting +12v from the ignition switch and batteries.
c) These trucks are sensitive to starter rpm. So charge your batteries 100% before trying to start it. If you are cracking slow it will struggle to start.
d) Make sure your glow plugs are working, no glow plugs, you will struggle. The block heater can be an alternative if the glow plugs are not working.

FYI if you have a 4.11 rear end, welcome to the 12mpg club! I have a C6 and a 4.11 and that is what I average. Want to get more MPH put a 3.55 and now you will get 15-16mph. (Maybe more if you have a velvet foot.). But you loose some towing power in the process.

None of the above works? Time to send it off to the pros to reset it or rebuild it. See the following tech article for vendors.

Where to go for injectors and injection pumps.

I wanted to post this since it is a weekly question “who/where do I go for injectors and injector pumps?” I believe this has been posted by vendor but not a list. Unlike a oil filter, ignition switch, or fan belt. Buying injectors and pumps at the auto parts stores or worse yet online have...

www.oilburners.net

Send some pics and keep us in the loop on progress.

Awesome thank you so much. I will say it was definitely maxed out only because I went counterclockwise two full turns and then when I went to go clockwise two full turns it actually hit a stop and was maxed out. I will give it a go and see what happens.