Low end power issue 6.9 help!

[84diesel6.9nonturbo]

My issue is still that my truck has NO towing power. Ive deleted... the tank selector valve... the fuel warmer... the water seperator... the lift pump... the lower hard fuel lines -(under the block)... After all that i have solved my air intrusion issues and have gained no power. I have cleaned my valves and put in a 7.3 return line kit.... that could be an issue??? Larger size lines???, same o rings, same copper washers, it all fits nicely. No leaks. I have some inline fuel filters where i deleted my old stuff for now so i can see if i have bubbles. (Ill replace the h20 flter and warmer once i can get her to tow my backhoe up hills. )*** im not off a tooth on timing, i checked my gear timing without issues. If anyone needs help with that i can walk you through it. If you pull off the upper gear housing (4 easy bolts) and dont mark it first your timing will be all screwed up. Yesterday i pulled the injectors out and added a shim to each one (inside the injector, between the bushings, above the spring. ) and put them back in. It sounded a little stronger and had a bit more pronounced diesel clatter (normal for 6.9s)... but It didnt help the power. Then i pulled the injectors out to check them on the drivers side and noticed chunks of pressed carbon on the copper washers where they seat in the bores on three. but the back one, copper washer and bore was cleaner and the injector was noticabley hotter.. and it was the only dry one. So i figured maybe its the dirty bores? I cleaned them by spinning a short dull chissle in the bore then a flathead wrapped in micro cloth. I blew air into the bores to clear out debris from the bores after cleaning them. After that i started it up and wow it got a louder more consistant clatter! Still has no power? I am going to try moving the ip timing around. The lower bolts were loose on it and one was missing a washer and unknowingly threading halfway into the ip housing hole. Now i have to try to adjust timing i guess? Maybe try to quiet it down a bit? I have no money to spend on this at all so any ear timing help would be great. Also, does anyone know roughly how far from the top my fuel screw in the pump should be? 2 or three flats back? Thanks in advance!

 

[FORDF250HDXLT]

do you know the history/miles on the ip and injectors? aged/high mile ip and injectors are the most common issue for lack of power with these old gals.
timing doesn't effect a whole lot if everything is up to *****.so long as it's between 6-10BTDC somewhere.
if it's a super high mile engine,low compression wont help.

even running good,for towing a backhoe in n/a form.don't expect too much.so long as you can't get out and walk beside the truck uphill,that might be all ya get lol.if you have 3.55's first stop; salvage yard for an axle w/ 4.10's.

 

[84diesel6.9nonturbo]

Not sure about the gears but 3 spd autoand itll do 85 on the hwy. But will get stuck on s steep driveway if i stop. Not cool. Im only hauling about 10k not very extreme. Its in decent looking shape has a dana 70. The guy said it has 150k meter says 50k and running. My 95 351w was a million times better at high or slow speeds under the same load. Im not happy with it at all so far.

 

[BrianX128]

Not sure about the gears but 3 spd autoand itll do 85 on the hwy. But will get stuck on s steep driveway if i stop. Not cool. Im only hauling about 10k

I know nothing about autos nor do I have one but this sounds transmission related more then engine to me. If you're giving it the hammer and it won't go but you aren't spinning tires on a steep driveway you might have some slippage of some sort somewhere else.

 

[Black dawg]

sounds like you have 3.50 gears.....and a no turbo 6.9. Have you looked up the hp/tq specs of that 6.9? It has been a long time since I had a non turbo 6.9, but I remember even a 3000 ish slide in camper would really drag it down.

 

[chris142]

I have 3.55 gears,timing where it should be,fuel turned up a little and a 4 speed. Pulling my 1500lb trailer with a 1300 lb ATV on it puts me in the slow Lane on any incline. On a real steep mtn road I'll put the transfer case in low range to get more gear reduction. I don't think i could pull 10k. at least not safely. I'd be blocking the lane for sure

 

[Hydro-idi]

How many miles are on your injection pump? Let's start there. That could be the main issue with your power problem. Tends to be quite common with these engines. If you got an old IP & injectors, they won't have any power.

 

[cpdenton]

Adding a shim to the injectors increases your pop pressure. With a pump of unknown mileage, there are a couple issues it could be causing. Your pump might be weak already, and a higher pop pressure might be harder for the pump to work rig. Your timing will be affected as well, because the injectors are a little later to pop open...

I would bet you need a fuel system upgrade.

Just for reference. My truck, before the banks turbo and 90 cc moose junior pump, would not pull my 7000 pound travel trailer at interstate speeds. I have 4.10 rear gears as well.

If you can get it timed right, and there are people on this forum that are willing to help, you might be a little happier, and you might find that the fuel system is wore out. Check out the timing we ice registry here, someone might be close.
http://www.oilburners.net/forums/showthread.php?70126-TIMING-SERVICE-REGISTRY


Question....is your injector pump painted to match the engine? If so, it might be original.

 

[Sparky95]

What color smoke does it blow?

 

[icanfixall]

First off you need an injection pump and injectors. then you need it timed. With 3.55 gear and an auto trans you will have issues hauling the load you posted. When you removed the injection pump gear cover and "checked the gear timing". Did you find the Dot and the Y timing mark in the cam gear? If you mixed them up you will be 180 degrees out of gear time and it will run but poorly. Here is what the gear timing looks like.

 

[FarmerFrank]

Not sure about the gears but 3 spd autoand itll do 85 on the hwy. But will get stuck on s steep driveway if i stop. Not cool. Im only hauling about 10k not very extreme. Its in decent looking shape has a dana 70. The guy said it has 150k meter says 50k and running. My 95 351w was a million times better at high or slow speeds under the same load. Im not happy with it at all so far.

You definitely have 3:55 gears.

My truck use to be a 6.9 N/A with the same transmission and gears.

I have towed 10k worth of trailer with that setup a few times and I remember clearly how second gear would lug to about nothing before it finally would drop into first on a long hill. When it finally caught first gear I'd keep that skinny pedal smashed to the floor boards while watching my gauges.

Oh ya and all that happening was usually around the bottom of the hill, not the last couple feet.


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[no mufflers]

now that I have a turbo and could still use more power its hard to remember what things were like when it was an n/a. I cant complain it pulls pretty good now.

it does sound like the transmission might be a little weak also. I have pulled things around the 10k mark and I use all the power its got but I can still keep up with traffic. when I pulled stuff with the truck n/a I remember being in the 35 to 45 mph range a lot.

if you are pulling heavy loads often and want to keep up with or pass traffic maybe you should get a PSD.

 

[jayro88]

This is what I would do:
1. Have realistic expectations. A N/A diesel isn't going to be powerhouse, but it will usually be reliable and get you to the top of the hill.....just not in 1st place. My '88 e250 N/A 7.3 c6 does fine with 5-6k behind it. Haven't had more then that.
2. At a minimum, rent a meter and check your timing. I would plan on replacing the pump and injectors.
3. You have a c6. The Torque converter is probably original and pretty sloppy. I replaced mine with a Hughes Diesel Low Stall towing converter for mine.
4. Look for a truck in a junkyard etc with a 4.10 rearend. Swap out the axles
5. Hunt for a used turbo kit. Many times you can pick a used on for around $500.

Your truck will get the job done, you will just need to invest a little time and $$ in it. Most likely you will still come out ahead $ wise versus buying a good used Powerstroke

 

[jeepj667]

10k is probably way over the tow rating. My 85 has a 12k combined rating. The truck takes about 6000 of that.

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[OLDBULL8]

Put that truck on a Cat scale with your back hoe hooked up. See what the total weight is. Without knowing that everyone is just guessing.

Truck=~6500
Trailer= ~4500
Backhoe=~12000
Total= 23,000 your way overloaded with estimated weight.
That poor little C6 is just crying for less weight.