perkins has a mind of its own

the other week on the way to goldsmith we filled up at winchelsea, then headed out the back roads of winch. running the same as always until it ran out of all power, and eventually stopped all together. i checked the fuel bowl, a little gunk in the bottom, cleaned it out and then we got going good again....problem solved...until it decided it wanted to rev passed 2800rpm, hold a constant speed up a slight hill without the accelerator down at all, then it stopped again. turned the key, it was straight back into life. did this a few times after that. on the way home it was perfectly fine, running the way it should. took it to the winch show last weekend, it was fine going down there, but on the way back it was revving its self passed the supposed governed speed, and lacked power. same as before but didnt stop.

does anyone have the slightest idea as to what may be wrong?

thanks for any suggestions, Mike

Just at a guess did you check the tank?

Maybe the fuel tank isn't breathing correctly.

Or sucking air somewhere along the fuel line.

Sounds like the governor to me.....

But Istbc

Mike, start with the Basics. Drain the fuel tank & make SURE that there is no gunk in it. Check that the pickup hose is ok, no pin holes in it. check the line from the tank to the first fuel filter for holes, kinks etc. Remove the fuel filter & FIT a New Filter. Check the old filter for crud. If it has more than one filter, change that also. Blow through All the fuel lines & make sure that they are clean. Real clean not just maybe. Check your air intake & air filter.Fit a new air filter. Make sure there are no air leaks on the intake side either. Then if it's still up the creek look to the expensive side of things. But always start with the basics. Cheers Tim

Mike - A diesel that wants to rev past its set maximum RPM without holding the accelerator down, generally has a major governor problem.
You will end up with a runaway and a blown motor if you don't get the injection pump into an injection repair crowd, very quickly, if it has a seriously worn governor.

However, the rev overrun could also be caused by excessive oil in the fuel .. an oil or fuel leak that's allowing oil or fuel into the intake manifold .. or a good dose of petrol accidentally mixed into the diesel.
Oil can get into a Perkins intake from the crankcase vent system. There should be a separator stopping any oil getting into the intake from the crankcase ventilation system .. but this separator has been known to fail.

Another reason could be a split or cracked pipe, or loose joint in a fuel line, that's allowing air into the injection pump.
Air in the fuel will make a diesel rev abnormally .. but it shouldn't go much over the maximum RPM limit, if the governor is working properly.

You appear to have multiple problems, as engine stoppage is generally unrelated to a worn governor.
Is the Perkins injection controlled by electronic solenoid? If so, the stoppage could be a faulty solenoid.

You need to start checking each potential problem, carefully, one by one, and continue by a process of elimination, until you find the cause.

Cheers - Ron.

alrighty, we cleaned the fuel tank out at one point because it had water in there along with moths and other things. only thing is it doesnt appear to run out of fuel, because when it stops the fuel bowl is still full, and theres no air in the lines. the air filter was a bit dusty, but no too bad. it would be much easier to diagnose if it was revving passed governed speed, it is like cruise control, dont need to touch the accelerator and it keeps on going so must be something to do with the governor. well time to whip off the pump i think :

thanks for the ideas, Mike

My c160 cummins is much the same when you first start up it revs up by it self and slow to drop revs untill warmed up then idle to slow :-?john

A diesel can pick up air in the fuel quite easily .. and air in the fuel will make it run faster.
It doesn't take much .. a pinhole in a steel line caused by corrosion (look for mud buildup between lines and chassis), or a crack caused by vibration (suction lines inside the tank can have this happen to them).
Sometimes an incorrectly-tightened fitting will do it.

You can soon find air in the fuel by cracking an injector line whilst idling, and looking carefully for bubbles.

I had a lot of trouble with my old Perkins in a tandem ACCO, that would just slowly die every once in say 500-800 kms. Stop for a while, and it would go again, no problems.

I eventually found the problem was a flat brass mesh filter screen that fitted into the lift pump housing above the glass bowl. It was held in by the glass bowl gasket, and it was almost impossible to see.
The screen was blocked almost completely with super-fine trash, and it would let some fuel through for a while, then stop the flow completely.
A stop for 15-20 mins would allow the trash to relax away from the screen, and let fuel through again for a while, until it blocked right up again.

A hardened glass bowl gasket, or a bowl retaining clip that's not tight enough, will also let air into the fuel lines.

Without hearing or driving it...here is where i would start.

FIRST...Double check all the stuff you played with while doin the air brake conversion!

Check every linkage for binding.

Take the return line off put it into a bottle with some diesel in it you will see the bubbles there..

Make sure the pre heater isnt stuck on trying to vapourise every drop of fuel.

Is it cable or electric stop, check that.

Check the governer FIRST don't pull the pump off until you have had a proper look.

If the air filter was blocked it would blow black smoke.
That wont make it rev anyway.

Chocs

Many years ago I had this same problem in a Perkins powered Commer. Stopped in the middle of Johnston Street Melbourne at the peak of rush hour.

Crawled under and took the fuel bowl off and away she went. Bloody truck stopped under a bridge at 3.00am on the Pacific Highway a week later - bowl off, runs again.

Stopped in the middle of Brisbane 3 days later - bowl off but this time crawled right under and thought I would pull off the, now discovered, fine screen above the bowl. The screen can not be seen unless you are directly under the filter so emptying the bowl will not fix a hidden blockage.

Turns out the screen was completely blocked with some sort of "floating" material like disintegrated paper that had compacted neatly into a ring on the screen and actually looked like it was part of the filtering system.

Cleaned it out and away she went. Continued to clean it out each day until whatever was in the fuel had stopped coming.

Before forking out for fuel pump/governer etc repairs , check the screen!

Lang