Case 350 Crawler kicking my butt

[frickenbored]

Hey everyone, I've decided to join an equipment forum because I've been trying to get my Case to start for weeks now with zero progress, and I'm hoping someone out there can help.

The tractor is a 1973 Case 350 crawler with a 188 engine. So some history...the tractor ran perfectly for countless years up until January of 2019. I live in Michigan so one day in January it was about 20F outside and I wanted to plow some snow. I had the case plugged in and it started with no problem in that cold weather, about 30 seconds of run time the engine started sputtering. That's when I saw a stream of diesel fuel spraying out of the return line via a loose return line fitting at the number one injector.

Once I noticed the fuel leak it was too late, the engine sputtered and died. So when I found that the return line fitting was not even finger tight I grabbed some wrenches and tightened all the return line fittings, I'm guessing they just came loose from all the vibration through the years. I tried getting the engine started for the next half hour but nothing happened. Not wanting to be in the cold weather anymore I gave up and let the tractor sit until spring.

Fast forward to this month. I've replaced the fuel filters, filled the fuel tank, bled the filters, bled the line from the filters to the injection pump, loosened all the injector lines and cranked the engine until fuel sprayed out, but this engine still refuses to start. I can get it running on a mixture of wd40 and starting fluid sprayed into the air intake so I'm thinking the compression is good and I find it hard to believe that all four injectors failed at the same time. When I crank the engine with the injector lines open I do get fuel at all four injectors but its just a small dribble of fuel, I've read that this is normal. Then I turned my attention to the return line after reading all kinds of stories about "mouse turds" turns out this Roosa Master fuel pump doesn't have the return line check ball, its just a normal tee fitting that screws into the top of the pump. I've blown the lines clear from the pump to the injectors and from the pump to the tank and it just doesn't look like the return lines are plugged.

So that's where I'm at, I'm starting to think that the pump itself went out and isn't putting out the required 2600psi to open the injectors but what confuses me is that I do get some smoke from the exhaust pipe when I turn the engine over (I guess that could be engine oil left on the cylinder walls). Also I'm confused as to why the engine died in the first place from a return line leak. I've read that people often open the return line and let the fuel dump on the ground to get the engine running when they have a plugged return line.

I would be extremely grateful if anyone has any suggestions. Also sorry for the novel.

 

[Delmer]

It sounds like you had at least three different things going wrong at the same time when it died back in January.

None of them might be relevant any more.

I can't think of any reason it won't start, so I'd start with the basics. Are you getting any air out of the injection lines or bleeding the pump?

Wait! did you loosen the injection lines AT the INJECTORS? You need to do that to get the air out of the lines themselves.

Take it easy with the starting fluid, a tiny bit while the engine is already turning only. On second thought, wait till it's warm again and don't use any starting fluid.

 

[thepumpguysc]

I need the # off the pump name plate..
While your out there getting it.. have a look on the backside of the pump & MAKE SURE the stop lever is ALL THE WAY in the run position..
That 1 sentence about the return line is alittle confusing.. u said it doesn't LOOK LIKE the return is clogged..?? U DID blow it out, right?
How much fuel is in the tank.?? 5 gallons aint gonna cut it..

 

[frickenbored]

It sounds like you had at least three different things going wrong at the same time when it died back in January.

None of them might be relevant any more.

I can't think of any reason it won't start, so I'd start with the basics. Are you getting any air out of the injection lines or bleeding the pump?

Wait! did you loosen the injection lines AT the INJECTORS? You need to do that to get the air out of the lines themselves.

Take it easy with the starting fluid, a tiny bit while the engine is already turning only. On second thought, wait till it's warm again and don't use any starting fluid.

Yes I loosened the injector lines at the injectors themselves and I dont see any bubbles when i crank it just some dribbling fuel. As for the starting fluid I only used it a few times but not before spraying a liberal amount of wd40 in the intake first to hopefully keep the cylinders lubed. I just wanted to see if the engine would start at all.

 

[frickenbored]

I need the # off the pump name plate..
While your out there getting it.. have a look on the backside of the pump & MAKE SURE the stop lever is ALL THE WAY in the run position..
That 1 sentence about the return line is alittle confusing.. u said it doesn't LOOK LIKE the return is clogged..?? U DID blow it out, right?
How much fuel is in the tank.?? 5 gallons aint gonna cut it..

I can get the pump number tomorrow morning, the stop lever is definitely all the way in the run position. I did blow thru all the return lines with compressed air, all of the lines are clear I get air all the way back to the tank. I filled the tank up to about 90% full with clean new diesel.

 

[Ronsii]

First off: quit spraying anything in the intake!!!!
Like delmer said it looks like you got more than one thing going on here.... the return line leaking was probably just a coincidence... the cold temps more than likely had more to do with the motor dying either from varying amounts of water where they shouldn't be or good ole bio-diesel gelling up in front of the IP either of which probably caused the IP to run itself dry. So now you need to force prime the IP and get fuel moving and all of the air out of anywhere it might be hiding.

 

[thepumpguysc]

& seeing it sat.. the metering valve might be stuck.?? easy enough to check.. 3 screws & the top cover comes off..
You can try to start it w/ the cover off, but it makes a pretty big mess..
If u don't know what the MV is or what it does or supposed to do.. google is ur friend.>> "Stanadyne/RoosaMaster MV"

 

[Fourtencustoms]

I own a Cat 350
for like 3 weeks now! LOL
However I have worked on a few cummins diesels in my day the injection system is about identical
The advice from Ronsii sounds like the ticket after all you describe and have tried.

FORCE prime the injection pump and get the fuel moving, any trapped air and it wont start.......

 

[frickenbored]

Ok so a small update this morning I went and took the top cover off of the pump, the pump cavity was only half full of fuel:


I sucked the remaining fuel out and checked the metering valve, it rotates nice and freely. I then cranked the engine over to watch the fuel fill the cavity and as the fuel level rose it started making a ton of bubbles:


And that's where I'm at. I'm guessing the bubbles aren't supposed to be there. I'm not 100% sure what you mean when you say force bleed the pump. I have pressurized the fuel tank before with compressed air to bleed the fuel filters and then again to try and start it but I got nowhere.

Also here is a picture of the pump tag:

 

[thepumpguysc]

Good info.. You are correct, the 42AJ does NOT take a return connector {check ball}..
So u know the mv is free but your concerned over the bubbles.. me too. lol
How do the rubber lines look.?? brittle?? How about any rubber grommets.?? split or hard.??
How about loosening all the lines AT THE INJECTORS while u have the tc off & see if u get any spurts of fuel AT the loosened lines..
I have 1 more test for ya..
Take off the INLET line & unscrew the 3/4 "transfer pump pressure regulator".. its the gizmo that the inlet "FITTING" screws into.. U can leave the fitting in..
BE CAREFUL when u take it out..!!!
Because, if its what I think it is, the guts will fall out.. There should be a rubber PLUG in the bottom of it..{black}.. Newer pumps have a steel plug.. that doesn't come out..
Check it out & see.. IF its good, LUBE the oring on the top & screw it back in.. NOT SUPER tight.. it'll snap off & then your done for the day..

 

[frickenbored]

Alright so I still get fuel spraying out at all four injector lines, at the injectors, even with the top cover off. I went ahead a pulled out the pressure regulator:



There is a steel plug, spring, and adjustment screw in the bottom of it...I pushed on the steel plug and it moves up and down freely.

 

[frickenbored]

Oh and also the bubbles in the pump cavity go away once the fuel level rises to about 1/3 full in the cavity so I'm thinking the bubbles are meaningless since that cavity is always full of fuel.

 

[Delmer]

Except that cavity was NOT full of fuel. Figure that out before you do anything with the pump or injectors that thepumpguy doesn't specifically tell you to check.

How about the filter? is the seal perfect on that? did it get twisted? two seals on top of each other?

I'd take apart everything from the tank to the injection pump, and blow something through any lines, just because air blows through, doesn't mean it's not full of junk that will block fuel. Get the line to flow clean bubble free fuel, then hook it back to the injection pump and see what happens.

 

[frickenbored]

True the cavity was not full...when I bolted the top cap back on I manually filled the cavity through the return fitting and so far it has stayed full. Both the fuel filters are sealed up tight and I dont see any leaks from the fuel feed side of the system. Tomorrow I will remove the fuel feed line from the pump and pressurize the fuel tank again and observe how much fuel spewes from the line.

I'm still thinking there's air somewhere between the fuel inlet to the pump and the injectors but I can't believe it's this difficult to bleed it...its supposed to be a self bleeding pump. Once I filled the cavity with fuel and tightened all the return lines back up I loosened the injector lines again and did see some bubbles from the lines so i kept cranking till the bubbles were gone and it definitely seems like there's a stronger fuel flow at the injectors now but the darn thing still wont fire.

 

[Delmer]

True the cavity was not full...when I bolted the top cap back on I manually filled the cavity through the return fitting and so far it has stayed full.


Both the fuel filters are sealed up tight and I dont see any leaks from the fuel feed side of the system.

That didn't fix the problem, or explain why it wasn't full when you had already bled it.

You won't see a vacuum leak that's sucking air. Pressurizing the tank is a handy trick, but it won't solve your problem either. It might get you going until next January...

Does this have any transfer pump? or does it use the injection pump to suck from the tank? or gravity feed? Either way, I don't think you're getting enough flow, or sucking air, or have a blockage still.

 

[thepumpguysc]

Did u snap a pic of the BOTTOM side of that regulator.??
U got me confused w/ your description.. u said it has a steel plug but u pressed on it & it moves freely.??
IS THERE a steel hollow plug THATS HOLDING the guts in.??
What u were pushing on is the actual piston..& theres a spring behind it, then the adjuster..
DO NOT EVER TOUCH the adjuster.. BAD THINGS WILL HAPPEN..

 

[thepumpguysc]

I kinda figured the bubbles would go away once u got the fuel flowing to it..
U HAVE TO keep the lines loosened AT the injectors until they quit bubbling & u get clear fuel out W/ no bubbles/air.. THATS THE POINT of leaving them loose.. its called BLEEDING the air from the lines..
Are u TURNING this engine FAST ENOUGH.?? Try hooking up a "booster" or hook it up to your wifes vehicle.. U don't wanna run YOUR battery down do ya.?? Lol

 

[Bls repair]

Supply pump pressure ok ?

 

[frickenbored]

That didn't fix the problem, or explain why it wasn't full when you had already bled it.

You won't see a vacuum leak that's sucking air. Pressurizing the tank is a handy trick, but it won't solve your problem either. It might get you going until next January...

Does this have any transfer pump? or does it use the injection pump to suck from the tank? or gravity feed? Either way, I don't think you're getting enough flow, or sucking air, or have a blockage still.

There is no transfer pump from the tank to the filters, all the information I've found says it's a gravity fed system. I'm gonna take a look at the little fuel bowl below the fuel shutoff under the tank, my dad had that apart while we were changing the fuel filters.

Did u snap a pic of the BOTTOM side of that regulator.??
U got me confused w/ your description.. u said it has a steel plug but u pressed on it & it moves freely.??
IS THERE a steel hollow plug THATS HOLDING the guts in.??
What u were pushing on is the actual piston..& theres a spring behind it, then the adjuster..
DO NOT EVER TOUCH the adjuster.. BAD THINGS WILL HAPPEN..

I'll snap a photo of it tomorrow after work. Other than the piston, spring, and adjuster there was nothing else in there. I was pushing on the piston from the bottom side and it was moving freely. Out of curiosity what happens if you turn that adjuster? Because I definitely did I took it apart to check for debris, but put it back to where it was.

I kinda figured the bubbles would go away once u got the fuel flowing to it..
U HAVE TO keep the lines loosened AT the injectors until they quit bubbling & u get clear fuel out W/ no bubbles/air.. THATS THE POINT of leaving them loose.. its called BLEEDING the air from the lines..
Are u TURNING this engine FAST ENOUGH.?? Try hooking up a "booster" or hook it up to your wifes vehicle.. U don't wanna run YOUR battery down do ya.?? Lol

I've been bleeding these injector lines for about 2 weeks off and on now, I have a brand new starter as of last month, and a battery charger hooked up to the tractor at all times. The thing actually cranks pretty fast. I have a pole barn where I work on cars so I have almost every kind of tool a mechanic would need. Problem is I was a heavy tech at a Chrysler dealer for 7 years and now I'm transmission test engineer for a major automotive supplier so I'm pretty mechanically inclined but diesel engines have never been my forte, I'm pretty dumb when it comes to diesel. I know this all sounds pretentious but I dont mean it to come off that way. But now you guys know I'm not a dentist who splurged and bought a tractor lol.

That all said thanks to everyone for all the help so far...its gotta be something stupid/simple that's keeping this engine from firing.

 

[Delmer]

We get you, and we believe you. It's just that you've tried all the common stuff, it still won't work, and what do you do now?

" I'm gonna take a look at the little fuel bowl below the fuel shutoff under the tank, my dad had that apart..."

That's one place I'd be looking, you should get a stead stream of fuel draining every where you open it up, depending on the filter and head pressure of course.