My first time pulling with the 6.9 story

[Rot Box]

I posted awhile ago about pulling a large load to Moab for my springtime vacation, and although I eventually got there I experienced problems with the 6.9, and was forced to dive the barely street legal 4x4 across the entire state of Utah! So here's my story...

The morning of I was loaded with camping gear and was pulling a single car hauler with my 4k pound Toyota truck on it. On the highway at 55mph I was blowing thick black smoke over 4 lanes of traffic, and the egt's were around 1100 degrees. Then the fun part came--Sardine canyon! At around a 5% grade 5 miles long I knew I would have a long pull so I threw it into third and tried to keep the rpm's high. Well that was the plan anyway.

Long story short I scratched at 1300 degrees for a very short period of time. Then eventually crested the summit at about 15 mph and not under 1150 degrees the whole time not to mention the (what seemed like) negative 10 mpg. Oh and the truck surprisingly still runs...

At that point in time I knew I had better take it home and park it. Going very slow doesn't bother me too bad, but the extreme EGT's and terrible mileage convinced me that something is definantly wrong.

What gives I've never really pulled anything with the truck until now, but judging by its behavior unloaded I thought it would probably be fine. So where do I start? I bought the truck a few months ago so the history of the injector pump, ip timing, and injectors is unknown. Maybe replacing them all would be a good start? What would you guy's do?

Anyway hopefully nothing was hurt but my pride

 

[funnyman06]

Well you might wanna start with getting the IP timed, or replaced depending on its status. We all know a poorly timed IP will really mess things up bad. My IP needs to get timed, but the 100 bucks the ford stealership wants isnt making me to happy. Mine blows smoke anytime i go up a good size hill, and im empty. That could fix your EGTs too, because if its putting fuel in late, then a lot isnt burning and its like putting insulation in your exhaust, everything will heat up real quick, plus you loose power because your not getting a good burn on the compression stroke. So loss in power, lots of smoke, bad MPG. My guess is get the IP timed.

 

[hesutton]

I'm no heavy hauler, but that certainly seems to be abnormal to me. Certainly, a NA IDI can and will make some dangerously high EGT's when pushed. You are one of a few NA guys that have a pyro.....most don't have a clue they are shortening the life of and/or killing their motors when driving/hauling in this manner. It only gets worse if the IP has been turned up on that NA rig. One of the reasons I think all diesel should have a pyro.......getting off soap box now...

The gearing (3.55) is not going to help. Plus, if you have larger tires than stock.......again, this further reduces your engine's mechanical advantage over the load you were hauling. That said, I think replacing the IP and injectors (and having it timed) would help a great deal IF they are the originals or have greater than 100,000 miles.

A turbo would also help with power and it would likely reduce your EGT's (as long as you don't go crazy with the IP) by making the motor a more efficent air pump.

Heath

 

[Andylad13]

when you say 4 speed trans in your sig, are you talking t-19 or e40d??

 

[92F350CC]

Bets are on T-19.

 

[Rot Box]

Yeah it's the T19, and my tires are 245's...

I'm pretty much convinced that it's the IP timing because it also won't start cold even after replacing the GP's

Thanks for the reply's and help

 

[Diesel JD]

Either the engine is already a basketcase or the timing is way off if you can't get it started cold. That is unless it has a lot of return leaks and such. I'd start with a compression test to see what the overall health of the engine is like. Next, if you have confirmed a decent powerplant, you should pull the injectors and have them pop tested. The IP is probably losing some of its punch if its over 100-150K miles, so replace it if you can afford it and the motor is good, and put the timing in the 1.5-2*ATDC range with the luminosity method or at 8.5*BTDC with the pulse method. Also I think if you are at higher elevations you'll eventually have to add a turbo or get a newer truck. NA models make dangerous EGTs at altitude under load. The factory added a HA pump which lowered maximum fuel delivery but also reduced nominal HP by 10-20HP. You could easily get away with a turbo if your engine is healthy if you just replace the headgaskets unless they are fairly new say under 50K miles and not leaking, and it makes it a different truck. For good compression values, book specifications suggest 260-440PSI with no more than a 25% difference between the highest and lowest cylinder. In truth 300-500+ with no more than a 25% difference is what you want to see with the evenness of the readings being more important than the values.

 

[RLDSL]

That load you were pulling shouldn't have made it fall on it's face. something is definitely wrong.
How many miles are on it?

 

[Agnem]

I'd say your experience is not that uncommon for a NA truck especially in a higher altitude. Long sustained grades are the worst for EGT's getting out of hand. The cooling system is pushed to the limits also, mostly due to heat from the oil cooler. You've got those piston cooling jets heat soaking the oil and really warming up everything. I'd agree that your fuel system is propably worn and in need of a refresh. Poor nozzle spray patterns don't help any, and that along with timing that isn't 100% all add up to a lackluster performance. I'd be asking yourself if your air intake and exhaust are flowing as freely as possible also. If you plan to stay NA, maybe you should consider a set of Stan's Headers.

 

[Rot Box]

Great information!

I bought the truck a few months ago with a broken speedometer cable Although I have no clue of the milage I'd have a really hard time believing that it is more than 180K by the condition of everything--but you never know...

I dug some receipts out of the glovebox awhile back and apperantly the IP was replaced two years ago, and the injectors where "serviced" by some guy so you know how that goes I also replaced all the o-rings on the injectors.

My wife keeps telling me to bail on the Ford and buy a first gen Cummins (did I say that out loud? ) maybe that would be money better spent... Na I can't do that. I will probably end up scheduling a checkup with my trusted local diesel doc, and see what he has to say

Thanks again,

Andrew

 

[Agnem]

You should put some info in your profile so we can see where you're from. If your're in range of the annual IDI Weekend you can get it timed for free.

 

[RLDSL]

I'd say your experience is not that uncommon for a NA truck especially in a higher altitude. Long sustained grades are the worst for EGT's getting out of hand. The cooling system is pushed to the limits also, mostly due to heat from the oil cooler. You've got those piston cooling jets heat soaking the oil and really warming up everything. I'd agree that your fuel system is propably worn and in need of a refresh. Poor nozzle spray patterns don't help any, and that along with timing that isn't 100% all add up to a lackluster performance. I'd be asking yourself if your air intake and exhaust are flowing as freely as possible also. If you plan to stay NA, maybe you should consider a set of Stan's Headers.

If everything is up to *****, even the altitude shouldn't effect it like that. Back when these engines were new, I maintained a fleet of busses out west with the these engines in them and I used to take them out on charters once in a while, and they were severely castrated, governed down to about 2700- 2800 max, but even the 79 passenger jobs with a trailer behind up in the high Sierras fully loaded never skipped a beat., in fact they would usually walk away from the supposedly better ,higher priced Crown buses with the mid engine 260hp Cummins ( OK so it still looked like an arthritic turtle trying to outrun a spaztic caterpiller, but the IDI did beat the things
Never saw anything that one of those things couldn't get up loaded , which is a whole lot more than I can say for the cummins. Lots of places up in the mountains , steep parking lots where they would have to offload passengers and make them walk because the darn things didn't have enough oomph to make it up.

These rigs were all geared fairly tall for city school routes for fuel mileage too, they weren't optimal for mountains.

 

[Dirtleg]

Well I can relate. I just pulled about 13,000 lbs plus my 7,000 lb truck from Houston Tx to Lynchburg Va last week NA. I too had extremely high EGT's for most of the trip. They were 850-950 on flat ground and 1150 on about a 2-3% grade. Running about 65 mph on the flats and as low as 45 on the hills. It was necessary to back out of the throttle on most of the climbs to lower the EGT's. I would back off when they hit 1200.

Once I got off the interstate and onto a state highway where the grades are steeper I would need 2nd gear to get up the hills. And the altitude was nowhere near as high as where you were pulling. Plus the hills, although steep at times, were short and rolling so I could get momentum for the next one most of the time.

Around here on some of the backroads I saw 1200+ EGT's in 1st gear with 190 + degree trans temps (have 40,000 GVW trans cooler installed) and 15 mph. I have a 3.55 rearend with 315/75-16's so not really a good towing setup.

It sounds like you need to get it timed for sure but it's not any worse than I feel I would have done in the same conditions. I am anxiously awaiting my turbo install.

 

[funnyman06]

Well you have to wonder much much of it is this dumb down fuel they are selling us?

 

[Rot Box]

You should put some info in your profile so we can see where you're from. If your're in range of the annual IDI Weekend you can get it timed for free.

I'll get right on that Though I've never timed a 6.9 I would definatly like to learn how to do so. I figured that it would be mentioned in the Tech articles, but maybe I missed it or perhaps it's too complicated for the average guy... Anyway being a maintenance mechanic I have a hard time paying anyone do work on my own vehicles


I would definatly sacrafice power for low egt's. It's seems like stock for stock without a factory pyrometer the average person should be able to just burry the throttle pulling a load under the max tow rating, and not have to worry about egt's as most people don't know better... I guess that's not always the case though.

Even without a turbo I think I'll be pretty happy with the truck once I get this problem solved