Cat 299D2 Cranks, Won't start

[david_]

I am at my wit's end. I drove it down onto a house pad and when the back end dropped off the 1' ledge the engine immediately quit. Hasn't started since. I had to have it craned out so we could continue work on the house.

I've gone through every setting and sensor in ET and pulled a PSR (attached) and everything looks fine except low voltage on the Aux solenoid.

Removed both air filters and sprayed ether ("Engine Starting Fluid") into the throat of the air intake, and it still cranks but simply will not kick off, even with ether. Diesels are so simple that it is incomprehensible that it won't kick over for at least a few seconds on ether.

Cranking draws a heavy load on the battery so I'm pretty sure there's good compression. I've been studying the engine manuals and have almost gotten through fuel injection, but no ideas yet.

I should also mention that it had been throwing a 'fuel rail leaking' code, so I removed the fuel rail and took off the overpressure valve, and found that the seat had eroded a groove for some reason. I'd replaced the fuel rail just a year ago for the same darned thing and it was $1,400. So I had a machine shop make a special plug out of bronze so I could use course then fine valve grinding compound to wear away that groove. The seat is not polished but it doesn't seem too bad so I put it back together. A groove eroded should not happen, especially in a Cat and especially not after about 200 hours and especially not with green fuel.

Even if that valve is leaking or even if the whole fuel system doesn't work, the engine should still kick off with ether.

Any suggestions? Need this machine or else have to rent one this week.

 

[Mbar]

I agree with the either thing. Are all the start conditions meet in et. What’s rail pressure. The transfer pump on those, if it is the square one with the filter attached to it are junk. Will it fill up a dry filter. Cat recommends not filling the filter when changing it to help verify the pump is working. Had a 259 the other day with a tank full of mulch that should die and not start back. Remember with common rail they will not sputter out and die. Once fuel pressure drops below threshold in rail it will power down like you turned the key off. Double check rail pressure with desired. Leaking injectors can cause pressure to be dumped backing into return system. Usually ether will spin it hard enough to overcome the leak and start. Cap off injectors to find this.

 

[david_]

Good question, what is rail pressure? Here's the engine; transfer pump doesn't look square.

The pre-charge fuel pump does clatter for about a minute when ignition on -- right after I replaced the fuel rail it was loud then it quieted down as it primed. And the filter fills about an inch.

Once fuel pressure drops below threshold in rail it will power down like you turned the key off.

Yikes. Maybe I need to loosen an injector pipe to let the rail fill. Then again, the injectors are supposed to be firing so they should let out the air.

Leaking injectors can cause pressure to be dumped backing into return system.

Understand, with the plunger chamber bypass, but the engine was running fine before the bump.

Used to be when I had trouble starting for other reasons ether would start it just fine for a few seconds. But not now. It's defying the laws of physics.

I've learned that the fuel rail overpressure valve activates at over 36,000psi! Wow. Maybe my grinding job is not good enough yet, but I won't know until it starts and throws the rail leaking code.

The fuel pump's gear pump feeder should have no choice but to feed fuel from the main filter to the piston pump, and the piston pump then should feed fuel through the check-valve, although the pressure regulator could interfere with that. But if fed the check valve should allow rail pressure to build up even when just cranking.

I'll check more stuff today. Thanks Mbar.

 

[Chrisso]

Is it throwing the fuel leakage code now? If so what exactly is the code? I see it's not on the PSR which is a good sign but is it coming up on the monitor?

If no codes, what's your transfer pump pressure? Need 12psi deadheaded and .5 gal/min straight from the pump. Sucking any air?

Maybe I need to loosen an injector pipe to let the rail fill.

This achieves nothing in common rail systems and is bloody dangerous.

 

[Mbar]

Rail pressure is the pressure in the common rail that the injector lines come off of. As stated. Losening lines does no got. If filter fill not fill change transfer pump after ensuring line is not clogged

 

[Mbar]

Rail pressure is the pressure in the common rail that the injector lines come off of. As stated. Losening lines does nothing. If filters will not fill change transfer pump after ensuring line is not clogged you can get plugs to cap off lines coming off rail and monitor pressure with et.

 

[david_]

It's not throwing a rail leakage code now or while cranking on the monitor. That sounds like good news. I do get a low battery code, but then I jumper and voltage goes up to 13.2.

I'll check the pressures and gpm. Don't know what deadheaded means. And the manual doesn't refer to a 'transfer pump' so not certain what that is. There's a 'precharge pump' before the filter, a 'feed pump' (the gear pump after the filter), and a 'supply pump' (the main piston pump) according to the manual.

I won't loosen an injector line, thanks. Idk if it's sucking air, haven't gotten to that part of the manual yet but it looks like a sight glass is needed.

 

[Chrisso]

Fuel transfer pump aka lift pump aka prime pump aka precharge pump. They're known for blowing fuses too, there'll be a fuse for it in the fuse box in the cab.

The other pumps you mentioned are part of the HPFP (High Pressure Fuel Pump).

Deadheading just means plugging the line you're testing. In other words, disconnect the outlet hose of the transfer pump, in you're case at the inlet to the main fuel filter housing, stick a guage in the end of the hose, then key on to give it 12 volts. You also want to hear that pump pulsing.

I would also be charging those batteries. Hate for it to be something so simple.

 

[Mbar]

As I stated. If it is that square pump that is picture above. If it will not fill a empty fuel bowl and no restrictions in the line. Throw that pice of crap in the trash. Just because they make noise doesn’t mean they are working. Cat keeps them in stock for a reason. The high pressure fuel pump is not designed to draw fuel from the tank. If you’ve been filling your filter housing and not letting the transfer pump so you it is bad you may have a failed pressure pump. Did you see what rail pressure is compared to desired during cranking.

 

[david_]

Ohhh, yeah I do have that piece of crap. It only fills the filter with about an inch of fuel but I thought that was because it hadn't started.

I'll show pics while cranking, in case I've missed anything. (click to enlarge)

Should the Start Aid Relay be off while cranking?

Looks to me like fuel rail pressure is 4,437 psi and delivery rate is 78.4 cubic mm, if I'm not mistaken. Looks like the engine is getting fuel, but where's it going? The oil doesn't smell like fuel.

Getting fuel but not kicking is consistent with it not kicking on ether. I can not understand why it doesn't run. But I will be getting a new transfer pump.

 

[Mbar]

Your 200 psi away from the desired psi. That means no start.

 

[david_]

O! Transfer pump?

Any idea why it won't kick on ether like it used to? Is it electronically inhibited somehow due to low rail pressure?

HA! From SIS2:

2018/06/26
A New Fuel Transfer Pump Is Now Used On Certain Compact Loaders, Multi-Terrain Loaders, And Skid Steer Loaders {1256, 1274} (M0093691-00)

Description Of Change: A new fuel transfer pump is now used, that will improve fuel delivery.

Adaptable To: The following parts are adaptable to the machines within the listed serial numbers, and are effective with all machines after the listed serial numbers.

PS - And yes a month ago I checked all fuses and found the transfer pump's was blown. I replaced it and now it runs, but apparently it can't keep up.


Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.

The new 552-5534 Fuel Transfer Pump Gp is a direct replacement for the former 416-5886 Fuel Transfer Pump Gp
Table 1
Parts List
Item Qty New Part
Number Part Name Former Part Number
1 1 552-5534 Fuel Transfer Pump Gp 416-5886
PPW-80008ABA
2022/05/10
15:42:12-07:00
i07385985
© 2022 Caterpillar Inc.

... and my model is included.

 

[Mbar]

Can’t explain the ether thing. If there is a throttle valve and not opening due to low pressure. Wouldn’t make a habit of trying to find out why

 

[david_]

Unfortunately, no dice.

Bought a new transfer pump, and it turned out the old one was the new part too. Installed it and no change. While cranking fuel pours into the filter but it never fills up, as if it's draining right back into the tank, just like before.

Here are the new readings while cranking. The PSR is attached.

I think the key is whatever the reason is that it will not start on ether. I do not see how that is possible though with a diesel. Is there a butterfly valve in the intake that's stuck closed? Or some other way intake air is being stopped?

Edit: The only thing in the intake air path is the turbo compressor.

This can only mean that the only thing determining engine speed is the length of injector squirts?! This seems implausible, but has to be the only way.

But I think that failing to kick on ether is the drop-dead Tell. Even if my fuel rail overpressure grinding job was schite it should still kick on ether.

I wonder why fuel flows out of the filter as fast as it comes in while not cranking and the transfer pump is still clattering? Where's it going? Back to the tank somehow? Should I shoot myself in the head in the parking lot?

 

[Nige]

After reading all the above, let me throw out an idea.

The problem is, and always was, a failing HP fuel pump (not the transfer pump). That, and a combination of rail leakage referred to above by the OP, is what originally threw the Low Rail Pressure Code.
Replacing the rail with a new one fixed some of the leakage, enough of it that the failing HP pump was able to generate sufficient rail pressure to exceed the "Desired Engine Injector Metering Rail" pressure - so enough to light the fires.
Now 200-odd hours later the wear in the HP pump has reached a point that even with what is effectively a leak-free rail the pump still can't generate enough pressure to cause the electronics to come out to play and inject fuel.

 

[Chrisso]

The problem is, and always was, a failing HP fuel pump

I'm also thinking this.

The suspicious sign as Mbar mentioned above is the actual rail pressure 200 psi below desired rail pressure... ~100 psi should be ok, 200 psi could be just under meeting conditions required to start. This is consistent with (and will trigger) your fuel leakage codes, the ones I'm guessing you cleared before taking the PSR. The only other items that cause these fuel leakage codes are bad injectors and a faulty fuel level sender in the tank. Your soot levels look ok, you'll know if the fuel gage reads incorrectly, so this too leads towards the HPFP.

The other thing that worries me is the failure rate of these fuel system components on your machine. It's done two fuel rails (given that the parts you replaced/repaired aren't technically serviceable from Cat) and likely now a pump at just over 2000 hours... first thing that comes to mind is fuel quality. Water is the likely culprit of erosion damage in fuel systems. Did you take any pictures of this overpressure valve you repaired? Would love to see.

While cranking fuel pours into the filter but it never fills up, as if it's draining right back into the tank, just like before.

I've seen this a few times on perfectly running machines with this style of filter housing. The air lock only occurs after replacing the filter and quickly goes away once engine is running. I wouldn't base any assumptions on this alone.

Can’t explain the ether thing. If there is a throttle valve and not opening due to low pressure. Wouldn’t make a habit of trying to find out why

It's in there...



Finally if you do the HPFP yourself don't forget it's timed to the engine and requires a calibration once complete. Also a really good idea to get that software upgraded by a dealer (I'd be inclined to do that first if it were me).

 

[david_]

Thanks guys. I don't understand how the HPFP could fail. The gear pump should be bulletproof. Although the pressure regulator system might be suspect.

Funny you should mention the fuel sender; it's reading almost empty when I'm quite sure the tank is at least 3/4 full. I'll try and get the sender out to physically confirm.

My lapping job on the overpressure seat was not the greatest. Probably didn't spend enough time with the fine compound as the surface is definitely not polished. I had no idea it works at such high pressures and could be leaking; don't know whether it would show a rail leaking code on crank, but should remove the rail and do a better job. Pics? Sure!

The rail.

The eroded gaps.

The special bronze tool I had made at a machine shop which fits perfectly square in the threaded hole.

In the process of lapping. Put a piece of paper towel in the center hole to reduce the grinding compound that gets into the rail body.

Hemostats are to carefully remove the paper towel.

Completed and cleaned with brake cleaner.

Water in the fuel. I'm one of those dummies who doesn't know where to buy red fuel in Everett, WA so I buy from the gas station, almost always a 76 station.

Yes I had prior cleared all of the logged Events and Diags, among them '1239-1 fuel rail leak', 'water in fuel' (opened up filter housing and there was sludge in the bottom, so cleaned), '523603-15 Coolant temp high'- (don't know when this could have happened), '1761-17 catalyst tank low' (not true), '3516-11 catalyst reagent concentration other failure', E232-1, E232-2, E570-2, E571-2, E875-1, E875-2, E875-3, 2212-5 . None have recurred. (yet) Egh this is embarrassing.

But I can't get past the idea that even if the whole fuel system is shut down, the Laws of Physics say a diesel should kick with ether. It is violating the Laws of Physics...

 

[Nige]

The fact is that on this type of common rail engine unless the Actual Rail Pressure equals or exceeds the Desired Rail Pressure during the cranking phase then the electronic system will not activate to fire the injectors and that's why no smoke comes out of the exhaust.

I don't understand how the HPFP could fail.

Simple. It is wearing out, probably as a result of various types of contamination (water, dirt, etc) that has passed through it during its lifetime. This is not a common or garden gear pump designed for pumping some sort of lubricating oil, it is one manufactured to much tighter tolerances made to pump fuel to almost astronomically high pressures.
As you mentioned Events logged for "water in fuel" and also you "opened up filter housing and there was sludge in the bottom" then there are the two likely suspects staring you right in the face.
Common rail engines don't like contaminated fuel..........

On slightly larger models of Cat common rail engines diagnosing low rail pressure events went something like this:-
1. Replace the Rail Pressure Control Valve which on those engines was a separate serivceable part. If that didn't fix it........
2. Replace the Rail. If that didn't fix it...........
3. Replace the HP Pump.
Basically it was working from the cheapest to the most expensive parts-wise.

Please note very carefully Chrisso's comment regarding the fact that the replacement HP pump will require timing to the engine if it is changed.

But I can't get past the idea that even if the whole fuel system is shut down, the Laws of Physics say a diesel should kick with ether.

I can't explain that unless there is another problem, also caused by contamination, that the engine is lacking compression. If the fuel system was as bad as your comments then what's the chances that the air intake system maintenance was of a similar standard.?
The only thing you can do is fix the problems as you come across them. Get the HP fuel system playing ball first, then see what happens. My opinion (*other opinions are available).

 

[Chrisso]

don't know whether it would show a rail leaking code on crank

The condition has to exist for a certain number of seconds to log a code, or maybe engine has to be running. Cat is known to fix/improve these issues in software upgrades. Helps with diagnosis.

Yes I had prior cleared all of the logged Events and Diags, among them '1239-1 fuel rail leak', 'water in fuel' (opened up filter housing and there was sludge in the bottom, so cleaned), '523603-15 Coolant temp high'- (don't know when this could have happened), '1761-17 catalyst tank low' (not true), '3516-11 catalyst reagent concentration other failure', E232-1, E232-2, E570-2, E571-2, E875-1, E875-2, E875-3, 2212-5 . None have recurred. (yet) Egh this is embarrassing.

It's not embarrassing, it's just Tier 4 Final crap. Next time take a "before repair" PSR with all the faults listed and post that instead, that way we can see the full story. The "water in fuel" logged event tells everything. As Nige said it looks like you're going to be replacing parts from cheapest to the most expensive. It's not uncommon in your case to replace a fuel tank sender, rail, HPFP and all 4 injectors in that order until the issue is resolved.

The book states the throttle valve is only used during during active regeneration. In reality who knows what it does the rest of the time. That info isn't readily available. It probably makes some kind of sense to keep it closed until all start conditions are met, ie adequate rail pressure.

 

[Chrisso]

But of course step #1 should be cleaning that tank out to remove that sludge you found in the separator.