DT466 low power

[Willis Bushogin]

I just bought a 1981 Int. 2500, S/A flatbed, with auto tranny. I bought it to pull my equipment trailer, because the truck I have, been doing this with has a 444E engine and it just isnt enough power. I drove the 1981 and even though, it didnt act like a 3406 Cat engine, it did seem to have more power than the 444E. I hooked a 28ft trailer, with a Bobcat and it almost killed it.
Im in the trucking business, but I have never owned a truck with a 466, I have always heard that, they were good engines. This truck only has 93,000 miles and it starts and runs great, just no power.
This is a manual fuel system, I have changed both fuel filters and air filters, still the same thing. It has a boost guage and pulling the trailer (without the Bobcat)
it has about 12 lbs boost, whatever that means.
OK Guys, whats your thoughts

 

[willie59]

I just bought a 1981 Int. 2500, S/A flatbed, with auto tranny. I bought it to pull my equipment trailer, because the truck I have, been doing this with has a 444E engine and it just isnt enough power. I drove the 1981 and even though, it didnt act like a 3406 Cat engine, it did seem to have more power than the 444E. I hooked a 28ft trailer, with a Bobcat and it almost killed it.
Im in the trucking business, but I have never owned a truck with a 466, I have always heard that, they were good engines. This truck only has 93,000 miles and it starts and runs great, just no power.
This is a manual fuel system, I have changed both fuel filters and air filters, still the same thing. It has a boost guage and pulling the trailer (without the Bobcat)
it has about 12 lbs boost, whatever that means.
OK Guys, whats your thoughts

Naw, it ain't no 3406 Cat, but...the 466 is a good engine and should have enough power for the job. I'm thinking most were around 185 horsepower. Dang good sounding engine with an open exhaust system. I tend to forget what boost pressure numbers are, but I'm thinking 12 lbs under load and on the throttle sounds a little low to me. Does it have a wastegate valve at the turbo that has a hose/line going back to the intake manifold? Do you have an intercooler? I've seen intercooler hose clamps loose causing loss of turbo delivery pressure. Also, a lot of these vintage DT's were manual shutoff. If yours is, is the shutoff control being pushed all the way in to the run position? Just a few thoughts.

 

[Willis Bushogin]

Dt466

Naw, it ain't no 3406 Cat, but...the 466 is a good engine and should have enough power for the job. I'm thinking most were around 185 horsepower. Dang good sounding engine with an open exhaust system. I tend to forget what boost pressure numbers are, but I'm thinking 12 lbs under load and on the throttle sounds a little low to me. Does it have a wastegate valve at the turbo that has a hose/line going back to the intake manifold? Do you have an intercooler? I've seen intercooler hose clamps loose causing loss of turbo delivery pressure. Also, a lot of these vintage DT's were manual shutoff. If yours is, is the shutoff control being pushed all the way in to the run position? Just a few thoughts.

No manual shut off, no wastegate, I checked the hoses to the cooler and they are not leaking. I plan on checking the condition of the turbo next.
I know this truck, has got to have more power than what it has, the state of Pa, had a bunch of them as single axle dump trucks, they pulled that load and now it wouldnt pull half that load.
Thanks for any suggestions

 

[td25c]

I agree 12 lbs is to low on the boost pressure.It should be around 15 to 20 at full throttle under load.If there are no leaks in the system and everthing else checks out ,I 'd say the injection pump needs turned up a bit.Another thing to check is "full throttle".With the engine off have someone step on the thottle and feel the linkage at the pump to see that its at full travel.On a "hot engine" that has been "turned up" at the pump ,its common to see 25 to 30 lbs of boost pressure.It could also have an anaroid valve on the pump.It senses boost pressure in the manifold and limits the amount of fuel the pump can deliver untill boost pressure rises.The dt 466 is a good engine and will make alot of power.

 

[Willis Bushogin]

Dt466

I agree 12 lbs is to low on the boost pressure.It should be around 15 to 20 at full throttle under load.If there are no leaks in the system and everthing else checks out ,I 'd say the injection pump needs turned up a bit.Another thing to check is "full throttle".With the engine off have someone step on the thottle and feel the linkage at the pump to see that its at full travel.On a "hot engine" that has been "turned up" at the pump ,its common to see 25 to 30 lbs of boost pressure.It could also have an anaroid valve on the pump.It senses boost pressure in the manifold and limits the amount of fuel the pump can deliver untill boost pressure rises.The dt 466 is a good engine and will make alot of power.

Thanks, Ill check on that throttle linkage
any ideas on how to turn the pump up? I have turned the pump up on a Cat 3306, thats easy

 

[willie59]

If you don't have manual fuel shutoff, it may be using a solenoid to turn on fuel, make sure it's pulling the fuel lever all the way in. And I've seen what 25c describes, over the years linkage get's worn and next thing you know the throttle pedal doesn't pull the injection pump lever all the way in, and even a small amount makes a difference. If you could inspect your turbo turbine and impeller would be nice. If your certain your fuel lines are good/clear, and you've replaced the filters, you might consider replacing the fuel lift pump. If it comes down to injection pump repair, your still going to want to replace the lift pump along with it.

 

[Willis Bushogin]

Dt466

If you don't have manual fuel shutoff, it may be using a solenoid to turn on fuel, make sure it's pulling the fuel lever all the way in. And I've seen what 25c describes, over the years linkage get's worn and next thing you know the throttle pedal doesn't pull the injection pump lever all the way in, and even a small amount makes a difference. If you could inspect your turbo turbine and impeller would be nice. If your certain your fuel lines are good/clear, and you've replaced the filters, you might consider replacing the fuel lift pump. If it comes down to injection pump repair, your still going to want to replace the lift pump along with it.

Thanks, guys
Keepem coming, the more things, the better.
It will be next week, sometime, before I can get around to much of this, but I will let you know, when we get it figured out

 

[hollywood]

You did say that the truck starts fine. However I have seen the check valve in the return line go bad and still allow the truck to start fine, then when there is a demand for fuel the pump can't build pressure due to a weak spring in the check valve, but most of the time you will have low power and hard starting. I would remove the check valve from the return line on the injection pump and blow through it. If you can blow through it, it is bad.

 

[Willis Bushogin]

Thanks, Ill add that to the list
Keepem coming

 

[willie59]

Thanks, Ill check on that throttle linkage
any ideas on how to turn the pump up? I have turned the pump up on a Cat 3306, thats easy

Does it have an aneroid valve on the injection pump that 25c mentioned? If so, look for a rather large plug in the area of the aneroid valve. If you find one and remove it, have someone start the engine and throttle it up to the governor. You should see a reaction viewing through the hole of the removed plug. If all this happens, it means the aneroid valve is at least operational and you should notice some form of adjustment in there. Been a while since I've done one, can't tell you much more than that.

 

[Willis Bushogin]

I have no idea what a aneriod valve is, but Ill check on it

 

[willie59]

I can't remember if your model has one. I remember the inline pumps did, but that's more around the mid 80's. If it has an aneroid valve, you should see some form of line that goes from the intake manifold to an assembly component of the injection pump. That would be the aneroid valve. There is usually a plug in the area of the valve to access the star wheel and adjust the fuel control. I found a webpage that has a little info that might help you out. Scroll down to the section on the DT466. http://www.freewebs.com/nevrenufhp/index.htm

 

[Iron Horse]

Torque convertor problem ?

Dragging reverse band ?

Binding brake ?

 

[Steve Frazier]

I've driven the 466 with both Allisons and sticks, and the autos seem like pigs compared to the sticks. The only way I've been able to get performance from an Allison equipped 466 is drive it like an old Detroit, pegged against the governor by manually shifting the auto. Our fire tanker is set up that way and I can almost stay with the pumper going to a call driving it that way. If I let the truck shift itself I lose sight of the pumper every time. It might just be the combo you have.

 

[willie59]

I've driven the 466 with both Allisons and sticks, and the autos seem like pigs compared to the sticks. The only way I've been able to get performance from an Allison equipped 466 is drive it like an old Detroit, pegged against the governor by manually shifting the auto. Our fire tanker is set up that way and I can almost stay with the pumper going to a call driving it that way. If I let the truck shift itself I lose sight of the pumper every time. It might just be the combo you have.

Hmmm, I haven't driven a 466 with an Allison, makes sense that they wouldn't have the same feel as a manual tranny because of the torque convertor. I think we're just curious about the 12 lbs boost. Even with an auto trans, I would think you should see more than that. I worked on a single axle Freightliner fuel tank truck that had a Cummins and an Allison. Driver said it wouldn't get out of it's own way on a hill. I found it had a bad wastegate control pot that was leaking the boost pressure that controls the aneroid valve. When that happens, the aneroid doesn't "turn up the fuel delivery" at turbo boost rpm's. Not saying that's the problem with this one though, several things yet to consider on this one, including, "that's just the way it is!"

 

[Steve Frazier]

I wasn't suggesting anyone is wrong with their diagnosis, just adding another idea. We've got two 1600 gallon tankers on 4900 chassis with this set up and they are both pigs. One firehouse has a hill right off the driveway, and from the other firehouse there's a long hill that divides half the town. These trucks are shamefully slow attacking these hills, almost to the point of me feeling foolish having red lights flashing while climbing them, lol. I guess the lights help prevent someone from running into the back of me. Even when these trucks are empty they aren't as snappy as you'd expect.

To the contrary, my buddy had a 6 wheel dump on an S-18something chassis with a 5 x 2 trans and that truck was a pleasure to drive. I took it on a 400+ mile trip through the mountains of upstate NY and had no trouble staying at traffic speed with 10,000 pounds load on. I rarely dropped more than one gear all day long.

I'm not familiar with any of the mechanical specs of the 466, and there might be something amiss with our tankers, but it seemed funny that they would both be pigs and I thought I'd mention it.

 

[willie59]

These trucks are shamefully slow attacking these hills, almost to the point of me feeling foolish having red lights flashing while climbing them, lol.

Let me guess....you had a guy on a bicycle pass you going up a hill! :Banghead :lmao :falldownlaugh

To be clear, though, I didn't think you were suggesting a flawed diagnosis. To the contrary, I think you and iron horse offered good possiblities. I think there's more to this one yet before we can say for sure what the problem is, if there is, in fact, a problem. But it's interesting trying to noodle through it.

 

[John C.]

Twelve pounds of boost is about 24 inches of mercury which isn't that bad for that year of truck. In that era the most boost I saw on highway trucks was 30 inches or about 15 PSI.

We had a twin screw dump truck with an eight speed that did OK going down hill. Luckily we hauled loads down hill and returned empty. A person could definitly ride a bicycle back faster than that truck would carry a load back up the hill.

What is needed is some factory performance specifications on that engine so some real troubleshooting can be done. Chances are that it needs a tune up and some tweeking in the fuel pump. But if you don't know what it is supposed to be at, you are basically peeing in the wind.

Good Luck!

 

[nevrenufhp]

The 466 of that era were that slow. That low of booost also sounds about right. The rotary pump can be adjusted, I just dont have any pix of what it looks like under the big square cover. I think the highest rating with that pump was 210 or 203hp.....but they run forever. If you really want to make something out of it, you can put an inline pump on it(the Bosch MW pump is a bolt in) with the lines, but I dont remember if the injectors are different. Also, pulloff.com has some high flow rotary pumps for sale from the sled pullers. It may be a tad smoky though. Much past 230hp, and you will need a better turbo.

 

[Willis Bushogin]

OK, I did a little checking today, I pulled the inlet hose, off the turbo, lot of loose motion in the blades. They are not hitting the sides, but its loose. Also the housing, is loose where it goes into exhaust end of the turbo.

Still couldnt make out the style of the fuel injection pump, let me try to explain
1.At the front of the pump, and kinda on top, is where the fuel lines hook up, that goes to the injector nozzles. In the center of the circle, is a nut, about 3/4-7/8" wrench
2.At the rear/back, is a funny looking unit, that has a wing nut, that holds the top on (I guess)
3. At the rear side, there is a steel line (about 1/4") that comes from the fuel control, to the intake manifold

Question???? where is the serial number for the engine located? Remember, this engine was built in 1980

Info:I do not have a wastegate on the turbo
Thanks for any suggestions
Does anyone have a good turbo for this engine?