MEP803A glow plug system questions - intake heaters

[AOR]

I have not had time to dig into the manual to start trouble shooting yet but I am hoping someone can answer a question for me. I own 3 of these units. I have one that starts up in the cold weather without any issues. I have another one that has had trouble starting for the past year or so and its acting like the glow plug system is not working. I noticed that on my known good working unit when I turn the switch to the preheat setting I often hear a higher pitched tone. I have not heard this tone on my other running unit which has trouble starting.
I do hear and see the relay clicking on both of my good units but I cannot seem to locate what is generating the tone on the issue free unit. Does anyone know what component makes that tone? I was thinking to try parts from my third unit which is my dead unit if I knew what to swap over.

thank you

 

[Guyfang]

First try putting the S1 in the preheat position, (get someone to hold it for you) on the set that is the problem child, while you hold a multi meter to the first glow plug, and ground. See if you are getting voltage. 24VDC. If there is no voltage present, then go to K18, and have someone place the S2 in the preheat position. Check from ground to wire #139B, for 24 VDC. Got it? If so, then check from K18-3, (wire #116A or 116A to see if you have 24VDC. Its always better to check to see if S1 and K18 is working first. So what you get?

 

[Ray70]

Out of curiosity, what do you consider "Cold"? The 803a will usually start down into the sub freezing temps without glow plugs.
Also, if you run the glow plugs for a few seconds you should feel the intake get warm it it's working.
The buzzing noise on the good unit has nothing to do with an indication something is "Working" or should I say the absence of that sound on the hard starting unit is not your issue. All you will probably hear is the loud click of the relay when you hit the S1 switch.
Assuming you know where the relay is, right? behind the bulkhead wall to the right of the K1 relay and left of the starter solenoid.

 

[Guyfang]

Also remember, a relay clicking, is not always a relay working. If you do not TEST, you can not be sure.

 

[AOR]

Thanks for your responses - I was not able to start it today at over 50 degrees outside. It has slowly been getting harder and harder to start even this past summer it was difficult it takes a bunch of cranking and smokes black and sputters until it eventually slowly clears up after maybe a minute or longer then runs just fine. I was planning to run my shop off of it to give it a workout and burn the 1 year old fuel out of it. I recently had triple hernia surgery so I am trying to not work on much until I heal up and when it warms up a bit more. I had several of these machines and I think they all made the tone or buzzing sound when putting the switch to preheat but this one does not do that so I did not know if there was another part such as a controller for the glow plugs like some vehicles have. I like to start my generators and run them up to operating temps every few months so they are ready when I need them. I should be clear in a few weeks to do light duty work and I plan to figure it out.

 

[rcamacho]

Check your fuel supply circuit.
My 802 developed a hard start condition below 50. Turned out to be the fuel water separator


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[Ray70]

Yea, you don't even need the glow plugs at 50F , you have something else going on. Go ahead and verify the glow plug system, but that's not causing your hard starting problem.
Which primary fuel pump do you have on it? a square pump or round E1074? While you're checking the fuel system you should verify fuel flow and pressure. These motors won't start well or at all without a little pressure upstream of the metering pumps. Might be a weak pump or clogging filter etc.
If it's in a damp environment you could be getting algae built up in the fuel and clogging the fuel system.

 

[AOR]

This unit has round fuel pumps on it. Is one better than the other? Someone once told me they are swappable from primary to aux I am not sure if that is true or not. I am charging the batteries back up before I can do more testing.

 

[Ray70]

I wouldn't say one is better than the other because they are both somewhat problematic.... Just that the square ones are older than the round at least....
Yours is obviously running but I have seen both styles run and move some fuel but not build any pressure.
Yes you can interchange between primary and Aux. but depending what style of aux. pump you have you may need an adapter or two... I don't remember off hand.

 

[AOR]

I have been cleared for light duty work and it was nice outside today. I used my thermal imager and I was able to see that all 4 glow plugs are working. I drained the water separator filter and some dirt did come out and the fuel smells old and weak. After thinking about it some of it is possibly 2-3 years old. It started up and I let it run my shop today for 4-5 hours. I plan to run it until is shuts off then put fresh fuel in it. I did not see any algae when I removed the strainer filler assembly and looked inside of the tank.