3-53 Detroit rack timing

[Fireman450]

Got a timberjack skidder a customer dropped off today.. It will turn over but not hit.. We are getting fuel to the injectors and air through the blower... I have no clue how to check the rack timing to see if its out.. any of yall that could help let me knoe.. info on the web is few and far between.. also any more info anybody might have about these things would be helpful.

Thanks for any info yall.

 

[JWhite]

What do you mean by timed, as in each injector has the same travel? Are you sure its not stuck closed?

 

[Fireman450]

We can see everything moving as far as the injectors and exhibit valves. Customer said when they tried to start it on either it kept back firing through the blower... while its turning over we are getting some white smoke from the exh. Just wondering if it could be way out if time?? Im clueless on where to look since I don't have a service manual.

sent from my toaster....

 

[autoferret]

i'll ask my father-in-law who is a deitrot guy tonight or tomorrow when i see him.

 

[9724VF350]

The injectors run off a camshaft lobe, the rack just changes fuel quantity if I remember right.

It's been a while, about 15 years ago I tore one completely down to nothing, bought the detroit manual, and put it back together. It's turned out perfect. Haven't turned a wrench on a detroit since then.

 

[1-5-3-6-2-4]

The injectors run off a camshaft lobe, the rack just changes fuel quantity if I remember right.

exactly. it is mechanical unit injectors. you will have to do a full tune up. that includes the rack and all the governor settings. you might not be getting the fuel shutoff fully open either.

start with that.

 

[lenahan05]

We can see everything moving as far as the injectors and exhibit valves. Customer said when they tried to start it on either it kept back firing through the blower... while its turning over we are getting some white smoke from the exh. Just wondering if it could be way out if time?? Im clueless on where to look since I don't have a service manual.

sent from my toaster....

if your getting white smoke then your getting fuel. so its not the shutoff. timing is off in my opinion.

 

[1-5-3-6-2-4]

if its not all the way open it won't run. Its a lever on the governor. physically open it full stroke. its that easy to verify.

 

[1-5-3-6-2-4]

A little more aggressive diagnosis might be in order. Are you a repair shop? What did it come in for? Was it running when it arrived? What happened to.it before? Does it have any compression at all? Does it run on ether?

But like I said start with a full tune up. A proper tune up, sets the racks and all the governor settings.

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[jimbo486]

I wish I could remember how to run the racks on a Detroit. It's been so long and I vaguely remember the adjustments at each injector's rack but I doubt I could describe it correctly. My terminology is probably off but I can recall watching the injector's rack as you're tightening the screw on the linkage. Once the rack rolls upward, stop and tighten the other screw to lock it. Using a flathead screw driver, push on the rack. If it springs back, it's adjusted correctly. It usually takes a few attempts until you get all of them adjusted correctly. I don't recall other steps required that lead to this one other than checking/setting governor gap but I believe once the rack is set, it should be ready to fire. This is all after having rebuilt it or part of a tune-up. And as Lenahan05 stated, white smoke means you're getting fuel. Hopefully someone can correct any info that I've mistaken.

 

[72chevy]

Is the rack free?

 

[Fireman450]

A little more aggressive diagnosis might be in order. Are you a repair shop? What did it come in for? Was it running when it arrived? What happened to.it before? Does it have any compression at all? Does it run on ether?

But like I said start with a full tune up. A proper tune up, sets the racks and all the governor settings.

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Yes we are a repair shop.. This is the first detroit Ive delt with so im on a learning curve here..lol
Backstory from current owner is the previous owner had the engine rebuilt and it ran great.. Well the owner (Older gentelman) passed away, His sons went to use the skidder and it had a fueling issue (They thought). They replaced the lift pump on the side of the engine and never could get it to run. Current owner brought it to us in this state... I understand that there are 2 different pumps (LH, RH rotation) It does have the correct one as far as i can tell by the amount of fuel we have at the injectors.

The rack apears like it is working properly. Both the kill and the throttle levers move freely and dont feel binded up.
Pulled the intake off the blower to make sure we were getting air, the blower turns with the engine.

Im thinking this thing may be out of time some how.. if you try to run it on either it will backfire throught the blower..
Anyone have any info on how to time this thing??

Thanks Fellas.

 

[Joesixpack]

Holy, been about 20 years since I worked on a Detroit and we used to have a pile of them around when we were logging.

So if I remember right, should have about 60-70 lbs lift pump pressure. Really can't imagine it being out of time, its all heavy duty gear train and the injectors are timed off the cam. So if its turning like it has compression it must be in time.

What buggered me one time pretty good, one of our engines had an air shutoff that no one knew about, and the damn thing tripped once. However you would have came across one if it had it with the intake apart.

 

[Joesixpack]

Still had a service manual kicking around.

 

[Fireman450]

I was wondering on the fuel pressure requirements.. wonder if that pump they put on could not be pushing enough??? Ill check the FP when it quits raining... things too big to get im my current shop...

 

[1-5-3-6-2-4]

Exactly as described. There is no injection timing, per say. There is lobe lift off the cam shaft, for cam timing. As mechanical unit injectors based off cam timing. If no ones had the geartrain apart, it's no possible to have changed since it was running. Verifying would be good thing though. You'd be good to guage the FP. pull the suction off the transfer pump, put your own hose into a clean bucket of diesel for suction to.the pump. That'll eliminate any restriction on the suction side and.the tank.

My 2 stroke manuals are at home. I mostly.worked.on 149s and 92s, They're all the same idea though.

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[72chevy]

Have you removed the valve cover to verify the rack is free?

 

[1-5-3-6-2-4]

Thinking a little more. White smoke, getting fuel but no compression heat. Sitting around for as Dolby ad you say it has. I'd be checking for seized rings. Pull the airbox cover off the side of the block, opposite the blower. Turn the engine over by hand and really check the rings. Push them with a screwdriver check for spring back of the rings.

That's an easy check as well. And you can get a good visual on the piston crowns and blower base.

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[1-5-3-6-2-4]

Before disabling it like that though. I'd disconnect the governor linkage from the rack, and try firing it running the rack by hand. Clamp a visegrip to the rack.

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[72chevy]

will the engine run on either? is the engine cranking in the correct direction? They made cw & ccw rotation engines. I had a customer call after he changed batteries, complaint being the engine would crank but not start we found the battery cables hooked up backwards lol.