Skid Steer Surge

[TFaoro]

Hey guys I figured I'd post this here and see if anyone had some thoughts.

I bought a Gehl 5640 skid steer with the BF4M2011 turbo diesel engine.

When I start it, it idles perfectly smooth for 2-3 seconds then begins to surge.

As I rev it up when cold it still surges until the rpms are over half throttle.

After 20min or so of running when the engine is up to temp the engine surge goes away at all rpms.

So far I've checked all of the fuel lines and replaced the lift pump.

Does this sound like a governor issue? Shutdown solenoid? Fuel pressure? Springs on the throttle cable or rack?

[Mopar1973Man]

Dumb thought after resolving a strange lope issue. Check your valve lash maybe too much gap. 

[TFaoro]

1 hour ago, Mopar1973Man said:

Dumb thought after resolving a strange lope issue. Check your valve lash maybe too much gap. 

It's very drastic though, not like a little lope. I do know the lash needs done though - as well as the timing BELT (Dumb idea IMO)

[nukethenazis]

If it has unit injectors, couldn't hurt to check the lash

[TFaoro]

54 minutes ago, nukethenazis said:

If it has unit injectors, couldn't hurt to check the lash

It has 4 individual external injection pumps and 4 injectors like a 12v. I'll try and get on the valve lash though.

[trreed]

If it has individual injection pumps, where does the governor reside?  Maybe it's a governor issue like the welder was.

[nukethenazis]

 

7 hours ago, TFaoro said:

It has 4 individual external injection pumps and 4 injectors like a 12v. I'll try and get on the valve lash though.

 

Yeah I'm not sure what else to tell you Tyler, just see if you can adjust the lash down in the block somewhere... 

 

Is this one of those engines cooled by the hydraulic fluid?

[TFaoro]

8 hours ago, nukethenazis said:

 

 

Yeah I'm not sure what else to tell you Tyler, just see if you can adjust the lash down in the block somewhere... 

 

Is this one of those engines cooled by the hydraulic fluid?

So the pump timing is adjusted by adding or removing shims from between the pump and block 

It's cooled by engine oil. 

@Mopar1973Man

 

[Wild and Free]

Must be a Deutz engine, I know Gehl uses them on their older machines. Couyld be a hydraulic issue too, wouldn't spend too much time on the engine until you do a hydraulic tune up first, if the pressures on the hyd pumps are fighting each other a bit will cause this too. Anytime you have issues like this on a hydraulic driven machine the hydraulic system HAS to be checked first. There are quite a few pressures that need to be set properly and if not will definitely affect engine performance.

[TFaoro]

2 hours ago, Wild and Free said:

Must be a Deutz engine, I know Gehl uses them on their older machines. Couyld be a hydraulic issue too, wouldn't spend too much time on the engine until you do a hydraulic tune up first, if the pressures on the hyd pumps are fighting each other a bit will cause this too. Anytime you have issues like this on a hydraulic driven machine the hydraulic system HAS to be checked first. There are quite a few pressures that need to be set properly and if not will definitely affect engine performance.

I believe one pump is for the boom system and the other is for the drive system - I'll look again one of these days.

 

As for adjustment, are you talking the relief valves or?? I haven't messed with hydraulic systems much.

 

It is curious how it only does it when the engine is cold though. The hydraulic system stays cool much longer than the engine, so it seems like more of an engine problem.

[nukethenazis]

Does the surging stop when you actuate any of the controls a little? 

[TFaoro]

15 minutes ago, nukethenazis said:

Does the surging stop when you actuate any of the controls a little? 

It dampens the surge, but does not eliminate it.

[nukethenazis]

33 minutes ago, TFaoro said:

It dampens the surge, but does not eliminate it.

Only other thing I can think of is maybe the swashplates in the pump(s) are actuating on and off a bit trying to regulate system pressure, but I'm not sure it would act like it does in the vid. 

 

Have you had any luck finding a repair manual or did it come with one?

[TFaoro]

15 hours ago, nukethenazis said:

Only other thing I can think of is maybe the swashplates in the pump(s) are actuating on and off a bit trying to regulate system pressure, but I'm not sure it would act like it does in the vid. 

 

Have you had any luck finding a repair manual or did it come with one?

So I spoke with a dealer yesterday, and they said that it sounds fuel related. They seemed very persistent about air getting into the fuel somehow, so I'm going to replace all of the soft lines and all of the clamps today. The dealer said nothing about the hydraulic system being able to cause it.

A guy on a skid-steer forum seems to think there's an "Idle surge screw" on these as well, so I'll do some research on that.

[TFaoro]

So I got some work done on the skid steer this weekend. I replaced all of the fuel lines (many were cracked)

I pulled the radiator and fan assembly back and removed the timing cover - The belt has been replaced, so that's a good sign. I also played with the governor adjustment a bit and it didn't make a difference with the loping. I set everything back to where it was though.

On ‎9‎/‎21‎/‎2017 at 8:45 AM, Wild and Free said:

Must be a Deutz engine, I know Gehl uses them on their older machines. Couyld be a hydraulic issue too, wouldn't spend too much time on the engine until you do a hydraulic tune up first, if the pressures on the hyd pumps are fighting each other a bit will cause this too. Anytime you have issues like this on a hydraulic driven machine the hydraulic system HAS to be checked first. There are quite a few pressures that need to be set properly and if not will definitely affect engine performance.

@Wild and Free do you know much about hydraulic pumps / valves? I haven't dealt with them much.

I did notice that the loping does continue while driving the machine, but if I use the boom / tilt cylinders the lope goes away while they're being used. Does that sound like a relief is sticking or adjusted improperly?

Edited September 26, 2017 by TFaoro

[TFaoro]

Sorry @Wild and Free I must have submitted the reply before typing my question!

Edited September 26, 2017 by TFaoro

[TFaoro]

So it quit surging.... no idea why, but I'm not complaining! Engine is smooth as butter now.

Fixed a BUNCH of hydraulic leaks this weekend. I think I've leaked about 5 gallons of oil since I got it, so this should really help.

The drive motor on the left side has been replaced, and I'm assuming they never replaced the O rings (2 per fitting.)

Onto the next thing!