955L stalled after running for 5 minutes

[empty pockets]

Hi, first time on here. I have a 955l which I have owned for about a year and a half. pretty tight machine, done torque converter and some hose work and only put about 120 hours on it. it always starts up within 2 seconds and runs great until today. It started up like usual and I let it run for about 5 minutes before higher throttle and moving to my project of building my lake. after about 50 feet it slowly lost power and died. No cutting out, it was a smooth loss of power till it died. It would not start back up. it has good fuel, clean air filter. I drained the tank plug and checked the fuel at the filter by taking the filter off. this is at my property that is just land, not at my house so any working on this means getting all tools from home which is 30 miles away. So limited what I could do at the time. I was wondering what next to check when I go out there. I hope to fix this myself if possible since I just spent 9,400.00 on torque converter. Any input would be very appreciated.

 

[ScottAR]

In order of difficulty.
Loosen the fuel cap. Could have clogged up vent.
Pull the intake line to the injector pump most engines have a screen there to catch gunk.
Suction screen in the tank. Maybe back flush the line to dislodge gunk.

It's not much but a place to start. Hope the problem is easy to find.

 

[Welder Dave]

It may have a screen in the fuel line at the lift pump that is plugged. Had the problem on my 931B and drove me nuts until I figured out exactly where it was and that it comes apart for cleaning. On my machine it's inside a longer hex fitting and comes out with an allen wrench.

 

[Old Magnet]

What s/n ? 85Jxxxx or 13Xxxxx? Also engine s/n would be helpful.

 

[empty pockets]

Thanks for the replies, It is a 85j11503, Sorry no s/n for engine until this weekend. I don't get home in time from work during the week, by the time I get to my property it is dark. I will take the line off where it meets the pump and look for a screen. the fuel filter was changed by the previous owner I guess at 3411 hours. I have 3606 on it so it should be time to change. I will call cat this week to get a new one. Donaldson P557440 is what is on it. I will clean the fuel cap vent also as ScottAR suggested. Again thank you all for any info.

 

[Old Magnet]

Well, that s/n is between my parts manuals but it appears it will have the sleeve metering injection system.
No hidden filters or screens, transfer pump on back of the injection pump draws from the fuel tank (no suction screen) to the fuel filter, then to the governor housing, through passages in the injection pump, on to the transfer pump which produces 25-30psi on the entire pump and governor. Fuel line from the tank is hose which is always suspect for internal collapse/blockage. What are you seeing for fuel pressure? There is a pressure relief valve under the injection pump side cover (lower right hand corner when facing pump) that can cause a problem if junk prevents it from seating. Your unit may also have a water separator on the fuel line which should be checked out.

 

[empty pockets]

Well guys, Its been a few weeks but after checking lines, installing new fuel filter, checking air filter and multiple charging of batteries which took forever since I am out where there is no electric. With no luck I gave it a snort of 50% either and upper motor lube it fired up. Ran it for an hour to charge batteries and shut her down. It did start right up again. Then the following weekend I went out to work on the dam and it wouldn't fire up like it always did before within 2 seconds. Shot of starter fluid and started right up again. I am wondering if all of a sudden some of my glow plugs are not heating. My fuel pressure gauge is pegged on high when running and within idle range when idling. any ideals on what to check next. I am not used to this, this 955l always started within 2 seconds every time without fail for one year and a half. Does giving it a shot of 50% either and upper block lube a big no no? I am about ready to put my new shanks and teeth on and sell this baby before its worth nothing and just hire someone to finish my lake. Any info from the vast experience of all of you would be appreciated.

 

[Old Magnet]

You should be able to tell if the glow plugs are working by observing the Amp gauge. Should take about 5 amps per glow plug.
What are you seeing for engine oil pressure? There is a stop in the governor that limits throttle until engine develops oil pressure. (never could find what that pressure needs to be). Either is ok if you don't get carried away with its use.

 

[Bls repair]

Sounds like may be sucking air in to fuel system ,you could try cracking injector line to bleed air out

 

[kshansen]

Also any chance of a couple pictures of the engine showing the fuel system? That way someone might be able to point to something to check. Cat has been know to change from one style of fuel system to another and each has it's own "special" problem areas.

Even sometimes having the S/N is not a full answer as on an older machine things may have been updated or modified over the years!

 

[workshoprat92]

I was always told using starting fluid on a machine that has glow plugs will destroy your glow plugs.

 

[workshoprat92]

You keep saying it starts up within two seconds or used to. What does this mean? Are you saying you get on the machine hit the start switch and it would start that fast? What is your starting procedure snd are you even heating your glow plugs before you engage the starter? Do you have the sticker showing the amount of time you heat the glow plugs given the temperature range of the outside air?

 

[workshoprat92]

Also there should be a water seperator filter up by the fuel tank. It will be square and glass and held on with a metal clip. Usually on the right side or the machine just below the fuel tank

 

[kshansen]

You keep saying it starts up within two seconds or used to. What does this mean? Are you saying you get on the machine hit the start switch and it would start that fast? What is your starting procedure snd are you even heating your glow plugs before you engage the starter? Do you have the sticker showing the amount of time you heat the glow plugs given the temperature range of the outside air?

Agree need a little more information.

If I'm reading this right it is now running good once started but the problem is now you are needing to give it a shot of go juice to get it running the first time.

Took some digging but found a poor wiring diagram that should be right for this machine according to SIS.
It does appear that this is a very basic electrical system. Should be easy to see if you have power getting to glow plugs using a test light or volt meter.

If there is full battery voltage getting to the glow plugs when switch is in "HEAT" mode you should be able to then check with an amp meter in line with one glow plug at a time. Normal amp draw on one glow plug is approx. 6.5 amps

Just a thought, if no volts are getting to the glow plugs while switch is in "HEAT" mode check for the wire that connects to the harness for glow plugs near back of cylinder head, common place for a problem on the 3300 engine wiring.

 

[workshoprat92]

Yes that diagram looks right! Very simple system. Would be very easy to check. From what i am hearing though im not even sure he is doing a pre heat procedure. His serial number is 85j11503 or close to that. Mine is 85j10889 so my machine is very close to this one. Thats a good machine and should have the d6 undercarriage vs th d5 undercarage on the 10000 and lower serial numbers. I have a manual if you need any info.

 

[DB2]

As kshansen says that connection between the main harness and the glow plug harness can be the problem. A crude bullet connection if I remember

 

[kshansen]

As kshansen says that connection between the main harness and the glow plug harness can be the problem. A crude bullet connection if I remember

Yes on the end of the harness that connects to the glow plugs there is a large bullet like connector about the same size a the top of a spark plug. Works okay when new but with age a corrosion not so good!

 

[DMiller]

Any of you guys have the resistance reading these plugs should have? I used to but cannot find my paperwork in my HUGE mess. Main point is if they have No resistance they are shorted(0 Ohms) may trip a breaker or pop a fuse/fuse link or if infinity on reading they will not heat up, either way. We used to install the fuse replacement style circuit breakers on older machines to save having to carry tons of fuses.

 

[kshansen]

Any of you guys have the resistance reading these plugs should have?

Not having any luck on SIS finding the spec's, seems like it should be there somewhere!

Best I can do is a hand written note in a 988 87A service manual that says 4.5 ohms and 24 volts. I would assume that most glow plugs in pre-chamber engines were somewhat close.

 

[Metalman 55]

Something similar happened to my 955L two days ago........was about 8f here in the morning & fired it up to load snow piles into the dump truck.........warmed it up good, then started loading & only had about 4 buckets on the truck & it lost power & quit. At least the engine was warm when this happened. The problem was at the tank valve at the bottom of the tank where the line heads off at 90 degrees........ice in the line right at the bend. Heated the area up with a small propane torch, dumped about a litre of methyl hydrate in, bled a couple of injectors & gave her a little smelling salts & away it went.