Terex w/Cummins B3.9C won't start

[Scotty Brown]

Hello everyone. I recently bought a 99 Terex 1048 with a Cummins B3.9C. It was running fine when I bought it 2 weeks ago. Sent a truck to pick it up (700 miles) and it wouldn't start. Between the time I bought it and sent someone to get it the temps dropped to about 16 degrees and the block heater wasn't plugged in. They thought it was cold so they plugged it in, but that didn't work after almost 2 days. Thought it was out of fuel so they added some and bled the lines. There was air, but still no start. The mechanic that bled it is stumped. I'm told there's black smoke while turning over still. One person is convinced the motor is shot and needs overhauled. However, I've never experienced an engine going from running to not after sitting a week because the motor was shot. I understand being more difficult to start when cold, losing power or excessive blue smoke, but that didn't happen. No warning signs as far as I know.

One thing I remembered from my previous Terex telehandlers was that it has a pump off button to disengage the hydraulic pump when starting cold. I don't know if they tried it or if it would even make a big difference. It had not been used a lot before I bought it, but it was started and ran fine just before.

Does anyone have any ideas? Something we're not thinking about? Do you think the pump off would make a difference? Again, I'm trying to do this from 700 miles away. THANK YOU!!!

 

[tractormech]

There's a screen in the tank on a SS 636-you may have one too where the fuel line hooks up. You will drain the tank when you remove it so have buckets ready. When you pull the fuel line off the fitting it should POUR fuel out- if it dribbles and shows poor flow pull the screen. The lift pump has a screen in it that can get clogged as well. If your pump is the type with the big knob you push then take the fuel fitting out that the fuel suction line is hooked to and look and see if the screen inside is stopped up. Also, I've had the spring in the lift pump break and it will pump a tiny amount of fuel but not enough to run. After you check the lift pump screen get a piece of fuel line and stick it in a can of fuel and see if the lift pump works with a known supply source. You need to be sure the cam lobe that operates the lift pump is at the bottom of the stroke (tip of cam facing away from pump) That will get you started. Let us know.Good luck.

 

[Vetech63]

Since you could plug in a block heater, try plugging in a space heater and heating up the engine a bit. With the temperature drop it may be as simple as ice in a fuel line and slow cranking speed.

 

[Scotty Brown]

Thanks guys, we did plug it in and also bled the fuel line and replaced the fuel filter, so I don't think it's a gelled fuel issue. I did at one point though. I'll send them the info on checking the screens too. Thanks

 

[TVA]

How it is shuts down?
Are you getting power to fuel solenoid?

Will it start on ether?

I had couple worn diesels that would start when it is hot outside, and won’t when gets cooler.
If the starter is good and not dragging, usually I heat intake manifold with propane torch for 10-15 minutes, then use mix of WD40 fine spray and starting fluid to start those ( be conservative on those sprays though).
But if starter or battery is weak - it ain’t gonna happen!
Those old clankers need good RPMs to build up the compression!

 

[Scotty Brown]

It will not start on ether. I don't know about the fuel solenoid but the guy I have out there mentioned it last night. We'll try and check that today. If there's no power to the solenoid or it's bad, will that keep it from starting even on ether?

 

[TVA]

It will not start on ether. I don't know about the fuel solenoid but the guy I have out there mentioned it last night. We'll try and check that today. If there's no power to the solenoid or it's bad, will that keep it from starting even on ether?

If it will not start On ether it means either low compression or timing issues.

Anyway, I said some stuff in previous post you can try.

 

[Scotty Brown]

Thank you. It does have some hours on it so I'm sure the compression is low. But I'm a little stumped as far as the fact it went from starting and running to not. The cold situation you mention does make sense to me. I'll have him try heating the manifold like you said. The battery is new, but they weren't using the hydraulic pump shutoff which would shut down that pump so that it can dedicate more power to the starter and spin faster. Thanks again!!!

 

[TVA]

Thank you. It does have some hours on it so I'm sure the compression is low. But I'm a little stumped as far as the fact it went from starting and running to not. The cold situation you mention does make sense to me. I'll have him try heating the manifold like you said. The battery is new, but they weren't using the hydraulic pump shutoff which would shut down that pump so that it can dedicate more power to the starter and spin faster. Thanks again!!!

I am familiar with SS machines, yes that pump will create resistance up until the point it will build up the max. pressure and de stroke.

These machines notorious for hydraulic systems internal leaks - so the pump might never de stroke until leaks are corrected.

BTW it is something you need to watch out for later - Hydraulic system overheating.

 

[TVA]

Thank you. It does have some hours on it so I'm sure the compression is low. But I'm a little stumped as far as the fact it went from starting and running to not. The cold situation you mention does make sense to me. I'll have him try heating the manifold like you said. The battery is new, but they weren't using the hydraulic pump shutoff which would shut down that pump so that it can dedicate more power to the starter and spin faster. Thanks again!!!

I am familiar with SS machines, yes that pump will create resistance up until the point it will build up the max. pressure and de stroke.

These machines notorious for hydraulic systems internal leaks - so the pump might never de stroke until leaks are corrected.

BTW it is something you need to watch out for later - Hydraulic system overheating.

 

[funwithfuel]

I'll bet a nickel, the little titty on the cam gear has sheared. It's just a little 3/16 nub. They like to break when temps dive and you don't have #2 fuel throughout. Bring number 1 up on TDC and see if pump is in time, if not, time to pull the front cover. Not a terrible job depending on accessibility

 

[Scotty Brown]

So, we got it home. The guy that sold it to us said it had water in the fuel (not sure if he's telling the truth). Regardless, he got it started and loaded, sat on the truck two days where it started right up, without any delay, to unload it. Warmed it up and drove it two blocks to the shop. Started it the next morning, again without any issue, to check operation of hydraulics. Shut it down for about an hour and re-started to pull into the wash bay. That's where it now sits as it won't start again. I'm heading over to see about water again and make sure it's getting fuel. I haven't ruled out low compression and the possibility that I'm going to pull it apart and put new rings, etc in it or look for a good used Cummins. Based on this info, anyone have any other thoughts, besides what's been mentioned? Also, does anyone have a good lead on a parts source for older Terex Square Shooter machines? It needs some TLC and if we're going to spend some time on the engine, we might a well repair anything else that's not working or wearing out. Thanks everyone!

 

[Vetech63]

That doesn’t sound like a compression problem. When it did start did it start right up? Is it having to have extended cranking time to fire up? It sounds like your fuel is cutting in and out......have you checked the electrical side of the fuel system?

 

[Scotty Brown]

I think you're right. When it starts, it does so within about 3 to 5 seconds of cranking. When it doesn't start, it blows black smoke. Took the extremely dirty air filter off but it didn't start. When it starts it runs smooth and there's no unusual smoke. Especially O ce it warms up just a little. Not even the blue smoke you'd expect from high hours or low compression. Maybe not related, but we just noticed one of the injector seals looks questionable. Also, it blows smoke from somewhere on the top of the engine, but only when it doesn't start. Can't tell where yet. Could this be a head gasket thing? I'm grasping at straws now. I'll see about the electrical side next.

 

[thepumpguysc]

Your stumped.??
The previous owner TOLD U it had water in the fuel and u kept running it.. It’s no mystery to me what to check.. pull the line off the filter and crank the engine to check to see if the lift pump is working.. if it is, change the filter..
Now see if u have power to the injection pump shut off solenoid, w the key on..
If yes, loosen all the lines AT THE INJECTORS & spin it over till u got fuel squirting out & tighten..
Does your machine have the air intake grid heater.?? If yes, make sure it’s getting power when u turn the key..

 

[Scotty Brown]

We were told that he drained the water out and replaced the filter. Is there more? I don't know. So, we're going to do everything you just recommended. Just to be sure. Thanks

 

[Jeff14889]

Before or after you try and bleed the lines make sure every fitting is tight, check for any porous rubber hoses, loose hose clamps. I’ve seen hard starts that a lot of times it’s air getting into the lines. Once running it’ll run good just won’t start for ****.

 

[Scotty Brown]

Hey everyone, thanks so much for the help! Just as a followup, we did virtually everything suggested and still couldn't get it started. It was getting plenty of fuel but and acted like it wanted to start, but wouldn't. Lot's of smoke though. We had a couple exhaust leaks that needed fixed and decided to go ahead and fix them while we were scratching our heads. Took the turbo off to fix the gasket and too it off at the intake manifold while we were at it. Looked inside and saw 1/4" of water. It had been leaking in though an empty intake bolt hole. Cleaned it all out and still wouldn't start. We felt like it wasn't always cranking as fast as it should though. The Terex has "pump off" switch that turns the hydraulic pump off when cold starting. Looked down and realized the wires were missing (cut actually). Fixed the wires, pushed the button and started right up! Has never failed to start again!! Was a a combination of water and not cranking fast enough. Not sure, but they both needed fixed anyway. So, thanks again!! Now on to our next issue. Hydraulics. Ugh!!!

 

[funwithfuel]

Thanks for the follow up. Glad you didn't chase the rabbit down the hole. Fixed what needed fixing and she's up and running. Awesome

 

[TVA]

Must be a Square Shooter before it became Terex ( or Genie for that matter).