MEP-803A Surge

[TVR-GEN]

Hello all!

I have an MEP-803A that has developed a substantial surge. When it's started for the first time of the day, it runs fine until it gets warm. As long as I apply load before it gets warm, it will maintain just fine, but if it gets to warm prior to a load being applied it starts to surge. Also as soon as open the AC circuit interuppter it goes to surging.

I can correct this surge by manually adjusting the little plastic knob on the governor control in the engine compartment shown in the photo. Is this a governor problem and what are my options?

Thanks I'm advance!

 

[DieselAddict]

What do you mean by manually adjusting the plastic knob? Do you mean pushing it towards the cut-off solenoid?

 

[TVR-GEN]

What do you mean by manually adjusting the plastic knob? Do you mean pushing it towards the cut-off solenoid?

I could have explained that better. Yes, you are correct. When it's under load, If I move it left about half way to cutoff, it will stop surging and will then maintain a constant RPM under load.

 

[DieselAddict]

Did this suddenly start or has it been something that has gotten worse over time?

 

[TVR-GEN]

Did this suddenly start or has it been something that has gotten worse over time?

It has gotten worse over time. There was a time when it was smooth regardless of load. At first it started surging when there was no load and ever so slightly. No it's a substantial surge at any load and the exhaust cover bounces at times.

 

[DieselAddict]

That is making me think the fuel rack has too much friction. If it had suddenly happened I'd lean towards the springs on the governor being damaged.

There is a plug on the front of the engine that if you remove it, you can directly push on the fuel rack. You can see if it moves freely. If it doesn't, I'd pull each fuel pump on the side of the engine one at a time and see if the tension on the rack changes. You may have a fuel pump that is gummed up a little and causing the extra friction.

 

[Ray70]

Maybe you can better explain what you mean by surge? Is it having a hard time maintaining steady Hz while load is being increased? Or do the RPM's fluctuate up and down ( or hunt up and down )when not under load, or when the load is suddenly dropped?
If so, that sounds like you need to adjust your droop setting a little.
There's a plug in the timing gear cover, under that is a hex head cap screw. You adjust that screw to adjust the droop of the governor, explained in the TM.

 

[2Pbfeet]

I would make sure that the solenoid and linkages are functioning correctly first, just to rule it out.

This may be the bias of my experience, but while a sticking IP can certainly cause problems, a surge that sets in after a diesel warms up would have me considering the possibility of a small air leak from a hose or fitting that expands a bit with heat.

All the best,

2Pbfeet