Bobcat CT335 extremely hard to start

[John White]

This thread caught my attention. Here is my story and "sticking to it". I just purchased a Botcat ct335 with a factory Bobcat backhoe. I purchased it from a dealer on Ebay. (not complaning or badmouthing him" who had purchased it from another dealer and couldnt sell it. It has 302 hours on it and looks to be in very good condition and hardly any wear indicated. I bought it "as is, where is". Dealer gave me a good price, "I think". He could not give ma any history of it. He said the instruments would not work. I took the dash out and replaced a relay and work fine now. they had the back off when I picked it up. The biggest issue I am having with it is that it wont start without spraying a little wd 40 in it and takes a lot of cranking then. I have checked the fuel filter, drained the tank and put fresh fuel in it, checked the shut off solenoid, cracked the injector lines to see if it is getting fuel, checked the glow plug relay and disconnected the connections from each glow plug and they all seem to draw the same. You can smell the diesel when cranking it over, light gray smoke. And when I do get it started it have to keep the starter engaged about 30 seconds or so to keep the engine turning till is will run on it's own and will run rough for a couple of minutes then advance the throttle to about 1200 rpm. I asked the Bobcat dealer if the valves might need adjusting. He said no, not with that low of hours. Any suggestions appreciated. So back to the back hoe, it is cracked right next to the bolt hole. Just a small seepage. I talked to a good welder and he said he could weld it back up but questioned weather it would crack again using the backhoe. If worse comes to worse, I can sell the backhoe and just use the tractor. Though I hate to do that because I got it to replace a Kubota B3030 I am not going to the expense of replacing the housing.

 

[sixdogs]

Re: Cracked Transmission case between bolts attaching backhoe

You might want to start a separate thread on the starting issue so it will get better viewing. But, maybe someone will answer here. I would be interested to hear how it turns out.

On the backhoe and crack, I've learned to pay attention to skilled welders.

 

[ovrszd]

Re: Cracked Transmission case between bolts attaching backhoe

Yeah, you definitely need to start your own thread. You'll get lots of activity.

So you know it has 302 hours on it because?

 

[aczlan]

Moved to a new thread, good luck finding a fix!

Aaron Z

 

[winston1]

Once it is up and running does it run with no smoke? Good power?

 

[seville009]

Where are you spraying the wd40?

If you haven’t changed the oil and filter, do that (didn’t see it mentioned).

How good is your battery? Might be worth it to put a new high cca battery in.

 

[thepumpguysc]

1>Does this have a decompression lever on it.?? It'll be a gizmo attached to the valve cover w/ a cable running towards the cab area..
2> your wasting your time w/ checking the glow plugs the way your doing it.. U HAVE TO SEE them or get a good volt/ohm meter..
just take them ALL out, hook them to your battery charger 1 @ a time.. + to the top & - to the body.. turn on the charger & count to 8-10, they should be cherry red..
disconnect it & lay it down to cool & check the others in the same manner..
If u find any that are slow or wont burn, obviously replace it.. I like to replace them in sets.. they all have the same burn time on them..
3> Do u have a compression tester.??
NOW would be a good time to test it.. thru the GP hole.. Harbor Freight sells a small kit that only goes into the GP holes..
U have to MAKE SURE the kit has the correct threaded adaptor tho.. if it doesnt, u could always buy a "die" & run new threads to the kit adaptor..
You'll probably need a "thread gauge" to determine what u have.. They make thread guages in both standard & metric for a couple of bucks..
4> u might have a fuel supply problem.?? disconnect the supply hose going into the inj. pump & hold it over a 5 gal bucket & turn the key switch on..
IF u have an electric supply pump, u should hear it clicking & pumping.. alot of fuel..
IF its a manual pump, meaning it runs off the engine while its starting/running, you'll need to spin the engine & watch the fuel pump out..
IF theres NO supply pump & its a GRAVITY feed.. the fuel will flow as soon as u drop the line below the tank..
Thats just a few things to check.. Good luck..
BTW> when u loosened the lines AT THE INJECTORS, was it pumping.??

 

[John White]

Today I removed all three glow plugs. I noticed that two of them had corrosion around them and the tips were sooty. The other one looked clean . I cleaned the threads on all them. Then checked then with a battery. They all turned cherry red in about 6 seconds. I went and bought a brass gun cleaning brush.
tomorrow I will clean the bore out. I think that is the problem. I had pretty well checked every thing else. Clean fuel, shut off, glo plug timer, proper cranking voltage.. I think the tractor has sat. for a long time and water got around two glo plugs. Has 50hrs. put on it since last oil change in 2015

 

[SSdoxie]

There is no decompression lever on this engine. Fuel flow is gravity fed to the mechanical lift pump then up to filter then to injection pump. The filter head has a 3 position valve lever for fuel ON, OFF, & Air (bleed) position. If the lever is in Air position or if seals in lever are not sealing tight the symptom described can occur. If cranked longer enough & fast enough it will eventually start. Won't operate at full power but will run because the injection pump is trying to draw fuel from both filter and return line. Check the lever position and if in doubt temporarily block off the fuel return line at the filter.

Injection timing can also cause this but shouldn't be a problem unless someone had been working on the pump and didn't check the timing after install.

 

[John White]

Well I am back to square 1. I thought the glo plugs might be the problem. Took them tested them cleaned signs of water corrosion off two. Still it will not start, without spraying we 40 in intake. And when it gets warmed up will just barely start after a lot of cranking. Thinking it must be injectors, I took them out and took them to a diesel shop and they tested them. All ok. Said it might be in pump. Before removing it I think I will try and round up a compression tester and see if compression is ok. I am wondering if water could have seeped through the glo plug into the cylinder. After it is warmed up it seems to run smooth above 1200 rpm but is a little shakey below that. Sure has been a problem. I tried to check every thinking in order before going on to something else. Process of elimination. Replace fuel filter, drain fuel tank and put new fuel in it, check fuel pump pressure, check shut off solenoid, and glo plug relay, remove glow plugs and check, remove injectors and check. If I got three equal size small bottles and put them under each injector line and cranked it over a couple of times and checked the volume, would that tell me any thing about the injector pump. I am guessing no unless one line had no volume at all.