Diesel trouble HElP?

woodster · Jun 1, 2015

does that engine had a secondary fuel filter if so change the eliment and rebleed the system and give that a try

KD3PC · Jun 2, 2015

stop solenoid or it's system is perhaps the culprit...it stops the flow of fuel, yet will be pressurized. SHould not be so high as to split a line though.

you might look at that?

woodster · Jun 2, 2015

KD3PC said:
stop solenoid or it's system is perhaps the culprit...it stops the flow of fuel, yet will be pressurized. SHould not be so high as to split a line though.

you might look at that?

you may have hit the nail on the head ....to the po can you see the fuel stop lever on the injector pump if so see if it moves when you power up the key switch or if you have an electric stop switch power up the key switch and have someone push the stop button and watch the lever and see if it is moving it is very possible that it's activated and not releasing ...although theses do not commonly malfunction they can and will because they are man made

Maine Sail · Jun 2, 2015

You "switched tanks" this often and properly requires two valves, supply and return to be redirected to the second tank. The return valve to the second tank may still be closed..... ??

jibes138 · Jun 2, 2015

Prime Time said:
2 mechanics have scratched their heads on this one.

just a WAG but how about the air supply? Any chance you choked off the air?

Ron20324 · Jun 4, 2015

How about the drain plug on the fuel filter? I had that happen last week. At the slip I drained the bowl, but had to start the plug with a hammer tap on the wrench. I was going to upgrade the filter housing, and had it on hand. But, I could not, so reinstalled the OEM. I later went 2 hours at 2800 rpm before the engine died. The drain plug came out with little initial resistance, and I realized I had not fully tighened it because was I going to change the housing. Tightened, bled, and all is okay.

CarlN · Jun 5, 2015

You confirmed the supply with a bucket test but did you confirm a return flow with a bucket?

centerline · Jun 5, 2015

Prime Time said:
Diesel mechanic is stumped:

Perkins Prima M60
Well maintained

4th trip of season. Running from Perth amboy to Annapolis. At cape May engine died suddenly just prior to switching from starboard to port tank. The port tank is about 30 gallons. Had been topped off in the fall by the yard. Filters on engine changed prior to trip. At time to change tanks, it was noted that the fuel in racor looked like strawberry quik. Despite using additive, new o rings on fill, filtering fuel and last yr emptying tank and cleaning it.. Fuel was drained from racor, filters changed, fuel flushed from lines and injector input lines. After bleeding, noted that fuel flow did seem poor while cranking. Would not start.

In cape may, mechanic repeats what I did and it starts for 1 min then stalls.

Then lift pump not working well. Eclectic fuel pump placed. Bucket with fuel as source. Fuel line to lift pump bursts.

Fuel line and return replaced.

Lift pump fine now. Purging air from injectors by cranking. Air purges. Won't start. Flow not so great from injector feeds.

What else could it be but a damaged high pressure pump?

I am assuming, by what you said, when it starts, it starts well and runs fine for "a minute"... but end up with air in the system.

So you can rule out everything except a leak.
The high pressure pump CANNOT ingest air in the system.

a plugged return line will cause it either to not run or run very poorly... a hole in it will cause a leak, unless it loops back into the system between the tank and the lift pump...

Sometimes in a diesel system, due to its necessary design, there can be a suction leak that will never leak a drop of fuel, because its never under pressure.
some systems can tolerate a bit of an air leak, and others cannot. You need to find where the air is getting in

what you should do is clamp off the return line as close to the tank as possible.. then disconnect the main fuel line at the tank... then raise the end of it above the rest of the fuel system (add an extension if necessary)...
Then gently top it up with fuel... then charge it with 20psi of air and holdmit there for a couple of minutes.. and the leak will show itself.

centerline · Jun 5, 2015

Prime Time said:
Diesel mechanic is stumped:

Lift pump fine now. Purging air from injectors by cranking. Air purges. Won't start. Flow not so great from injector feeds.

What else could it be but a damaged high pressure pump?

Upon further reading i see there is more to the story... a plugged return line, or plumbed in improperly can cause the injector pump to shut down or act abnormally to the point where the engine wont/cant run.

On that system i dont know if you have an electric fuel shutoff solenoid or a manual shutoff, but with an electric solenoid, you may see a residual amount of fuel at the injectors while cranking, even if the solenoid has failed or lost power, but there will be no pressure to it... there has to be high pressure at the injector nozzles to pop them open so the fuel can spray in the cylinders...

And a failed injection pump can act in an identical manner. So make sure the solenoid is working and opening properly before replacing the pump.. its unlikely that an injector pump will fail all at once, but its not unheard of.

Solenoids do fail suddenly or intermittently, and its probably the problem if the air leakage has been solved.

capta · Jun 6, 2015

Are you using thread tape on your fuel system connections? If so any one or several of them could be taking in a bit of air. Remove the thread tape and use Indian Head shellac (available in any US auto parts store) for ALL threaded connections on your fuel system (including the filters).
When the engine does run and die, have you inspected the Racor? If there is a restriction before the Racor, the engine will run on the fuel in the Racor, where the cartridge is, until it is gone. If you open the filter housing and the fuel level is not to the top, you have a restriction before the fuel filter. I've had the Racor 500 foul BEFORE the filter cartridge, in the internal piping of the filter housing. Boy was that a hard one to find.
Good luck.

DEB AND DION · Jun 7, 2015

I Am A Diesel Mechanic And Have Had To Find All Kinds Of Problems. The Suction Line Can Suck Air But May Not Leak When Air Pressure Is Put To It. The Fuel Filter Are Housings Can Leak Around The Fittings, Or From The Filter Housing It Self. If You Remove The Suction Line From The Injection Pump. HOOK UP A FUEL LINE AND Use A Electric Fuel, Or A Hand Fuel Pump And Put A Fuel Line Into A Can Of Diesel Fuel, Then Bleed The Fuel Sys, You Have By Passed All The Suction Lines. If The Engine Run The Problem In In The Suction Lines, Or Filter. The Problem Should Not Be The Stop Solenoid Because You Said Engine Ran After The Air Was Bleed Out Of The Fuel Sys. It Should Not Be The Injection Pump Because It Engine Ran, And The Injection Pump Is Under Pressure From The Lift Pump Or The High Pressure The Injection Pump Is Making. The Last Thing That I Have Seen Is A Bad Check Vale In The Injector That Is Letting Compression Backing Up Into The Fuel Sys. But You Had The Injectors Rebuilt. And It Should Miss On The Cylinder That Has The Bad Check Valve.

jibes138 · Jun 8, 2015

Prime Time....thanks for sharing your conclusions. It helps all of us to know what to look for given certain symptoms, makes a nice checklist item. Let us know how it works out when you get the parts back, Thanks again.

NCBrew · Feb 25, 2023

Prime Time said:
The injectors were removed and hi pressure fuel pump sent for bench testing. The air was coming from bad injectors staying open and sending air back to the high pressure pump which sent the air to all cylinders. The pump was damaged as well by the water. They are all in the process of being rebuilt.

I took out the high pressure pump then decided to put it back in. I am trying to remove it again for testing but it will not come out.