Governor not responding on 3204 Cat 943

[Steve A]

A while back I bought a Cat 943 track loader with a spun rod bearing, I didn't know what the problem was until I got it in the shop but I expected major engine work. Once in the shop I dropped the pan and found spun rod bearing with crank journal damage. I removed engine, had block hot tanked, inspected, re sleaved and new cam bearings installed, Had crank welded up and turned, assembled engine myself, head was checked, and all new valves installed, replaced all 4 fuel injectors, the one thing I did not work on was the injector pump, I simply cleaned and re installed it. On start up day It fired up and ran smooth, no smoke but if I reduced the throttle fast it would just die, if I slowly reduced the throttle to a slow idle it will idle.
I used it to move a couple buckets of dirt and was happy to find everything else seemed to operate nicely just no response from the governor. On advice from EDB at the ACMOC site I tried adjusting the governor damper screw. it made no difference at all, I removed screw, blew air through hole and even removed back cover to inspect and clean, no difference, a few days ago I started machine after sitting for months, it started instantly and ran without smoke, I tried removing damper screw with machine running and 50 psi of oil pressure, only a small dribble of oil flowed out, This I find odd. like I mentioned above I assembled this myself and I am not a professional, I was very careful with all the o rings under the oil cooler and between cooler and pump but fear I missed something, where did I go wrong? 

 

[Welder Dave]

Did you bore it and install sleeves? The 3204 is a parent bore block. It's possible the small strainer in the fuel line going to the IP is plugged. It's inside a long hex fitting and can be removed with an allen wrench once you remove the hex fitting. I had this problem on my 931B and it drove me nuts. Machine would idle fine but try to move and it wouldn't rev up enough and after several tries to get it to move more than 10ft. at a time, it would die. Wait a bit and it would start again and do the same thing again. Cleaned the screen and problem solved.

 

[Coaldust]

Hmmm. New Scroll fuel system. I wonder if the governor is receiving enough lube oil ? I don’t recall where the lube supply comes from. You got a book handy?

 

[Steve A]

Did you bore it and install sleeves? The 3204 is a parent bore block. It's possible the small strainer in the fuel line going to the IP is plugged. It's inside a long hex fitting and can be removed with an allen wrench once you remove the hex fitting. I had this problem on my 931B and it drove me nuts. Machine would idle fine but try to move and it wouldn't rev up enough and after several tries to get it to move more than 10ft. at a time, it would die. Wait a bit and it would start again and do the same thing again. Cleaned the screen and problem solved.

It had dry sleeves installed, they were replaced, I did clean the fuel strainer before the fuel filter that is new, I did not check fuel pressure although it will rev up and maintain full RPM, at least it sounds like full RPM, haven't checked. I will rig something up to check fuel pressure.

 

[Steve A]

Hmmm. New Scroll fuel system. I wonder if the governor is receiving enough lube oil ? I don’t recall where the lube supply comes from. You got a book handy?

I have a 3204 book but for a different arrangement on the fuel system, I suspect a lack of oil supply to governor also. I believe it travels through the oil cooler

 

[Nige]

I have a 3204 book but for a different arrangement on the fuel system,

What's the machine & engine S/N.? I might be able to find the correct book for you.

 

[Welder Dave]

The machine must have a lot of hours to have had liners put in and then replaced again. 3204 turbo engines are known for more frequent rebuilds though.
I'm not sure how much load the hydrostatic transmission puts on the engine but my machine would rev. up in neutral but fall on it's face when I tried to drive it. It took me about 45 minutes to move it less than 1/8 of a mile. I guess the trick is figuring out if it's a governor issue or a fuel supply issue or a combination of both. Not sure if there could be o-rings or something deteriorated in the IP that could block fuel flow like I've read about on some other IP'S.

 

[Steve A]

What's the machine & engine S/N.? I might be able to find the correct book for you.

I can tell you the tractor ID plate list tractor as 04Z0046 and Engine as 45V42046, this is Normally aspirated, no turbo The serial number plate is gone from block and nothing readable underneath. If I had to guess this engine was a replacement sometime in the last 30 years

 

[Welder Dave]

If the engine was replaced it may be a lower HP spec. than the original. Does it have 2 or 3 ring pistons? Nice looking machine.

 

[Nige]

the tractor ID plate list tractor as 04Z0046 and Engine as 45V42046, this is Normally aspirated, no turbo The serial number plate is gone from block and nothing readable underneath. If I had to guess this engine was a replacement sometime in the last 30 years

I see what you mean. Not necessarily based on the 45V24046 engine number I came up with this for the fuel system. Is it the same as the book you have.?

BTW you missed a digit on the machine S/N. The last digit is only faint on the plate but the S/N is 04Z00461. Built September 1984 and the engine S/N matches what's on your plate.

 

[Steve A]

I see what you mean. Not necessarily based on the 45V24046 engine number I came up with this for the fuel system. Is it the same as the book you have.?

BTW you missed a digit on the machine S/N. The last digit is only faint on the plate but the S/N is 04Z00461. Built September 1984 and the engine S/N matches what's on your plate.

View attachment 269710
View attachment 269711

The book I have is a parts manual for 45V1-17159, the oil cooler and fuel system is not even similar to what I have. Thanks for your assistance, I am not up on all the parts numbering systems.

 

[Nige]

The book I have is a parts manual for 45V1-17159, the oil cooler and fuel system is not even similar to what I have.

Take a look at the pdf I attached above and let me know if it's any help. If it's not I can keep looking.

 

[Nige]

Depending on the engine model, it appears as though the S/N plate could be either on the Top Rear corner of the LH side of the block or on the RH side.

 

[Steve A]

Take a look at the pdf I attached above and let me know if it's any help. If it's not I can keep looking.

That PDF will be a huge help, I will study that and remove the back of the governor and see what I can figure out, Thank You. RE the engine serial number, I believe it was intentionally removed, I am sure the attached pic is the spot, you can still see the drive rivets that were sheared off, I can only think of one reason to remove a serial number .

 

[Nige]

RE the engine serial number, I believe it was intentionally removed, I am sure the attached pic is the spot, you can still see the drive rivets that were sheared off, I can only think of one reason to remove a serial number .

I agree with you. The drive screws have been chiselled off.
It's probable that with judicious use of paint remover you might just reveal something (I can see the remnants of some stamping in your photo about halfway between the two screws) but I wouldn't bet the farm on it.

 

[Welder Dave]

If I recall the shop that rebuilt my engine removed the SN plate but put it back on. Maybe because they hot tanked the block? The SN plate is missing on the Cummins in my grader but I took some pics. of the same engine plate on another similar grader I saw for parts at an auction. It's 3 years newer but the same HP and specs. Hopefully I won't need any major parts or at least not for a while. It is running great now.