803a Metering Pumps, Random Questions

[Iron.Horse]

Good Evening Guys,

I have a couple questions that have me a little stumped.

First of all, I have a engine that is pulled from a 400hz unit that is intended to be a donor motor for a 60hz machine with a bad engine. Upon investigation of it, I found that the fuel rack was stuck and I figured that the pumps could use a good cleaning. I have pulled plenty of fuel pumps out before and figured it wouldn't be a big deal. After soaking them for a while, I started reasembly and figured out after a while that slot/pump "3" wasn't cooperating. Every time that pump was introduced into the line-up it caused the rack to have issues. I played with it for quite a while and have ultimately figured out that the internal plunger that pushes up on the fuel pump spring (and thus creates the pumping action/pressure) is in a slightly elevated position not allowing the metering pump to sit down where it is supposed to. I have read that by dead cranking the motor it should change the position of the plunger, but turning the engine over by hand via the front pulley didn't change it's position at all. Is there a reason dead cranking would produce a different result? How else would I get the fuel plunger down? I did spray PB blaster in there to see if it would free up any.

Seccond, I have a unit that I am chasing the elusive "no power" (well actually 30 or so volts, but it isn't field flashing to produce power). I have done VR testing but the readings are all over since there isn't sufficient power to it. I know the OHM testing of the stator (per the TM) is difficult becasue of the tight tolerences and "lower quality" volt meters... At what point do you pull the gen head apart to check the individual components? I believe this was a non-fuse modded unit, so I wouldn't be totally surprised if something is messed up internally.

Also, is there any reason not to use a good engine de-greaser and either wash out or gently power wash the engine bay of a couple fully assembled units that are fairly dirty from leaking fuel lines? I would normally shy away from any water in there but it seems like that is the only way to get rid of the oil residue. I am well aware of not introducing cold water on a hot engine, but my concern is more of the electrical connections...

 

[Ray70]

Dead crank Vs. turning by hand are no different. If you turned the motor a good 90* or more and the cam follower is still holding the metering pump up more than 1/8" - 3/16" off the block, then I would suspect it may be stuck. Hopefully the PB blaster trick will free it up.
Lets get it running right before chasing the voltage output issue.
I steam clean every generator I get, inside and out, but hot water dries faster than cold so I'd suggest blowing out all the little crevices with compressed air of a leaf blower when you're done.

 

[Guyfang]

The problem with trying to fix more that one gen set per thread is that people have to keep each gen set straight in their head. Not good. Start another thread for your other BD gen sets.

 

[Iron.Horse]

So I'm still not getting this fuel metering pump to seat. I've put PB Blaster down the hole and clean motor oil, tried turning the crank to all different positions while putting my finger down there to feel if the plunger is moving, and nothing. Is there anything to freeze up or break inside the motor that would cause this? The unit had an oil change/filter in 2019, and appears to have around 690 hrs on the clock. Compression is nice and tight. I even tried a different metering pump to make sure there was no difference. The only thing I can think of at this point is to actually run the machine on 3 cylinders or dead crank and see if the repetitive motion might jar it loose similar to an impact? I am just hesitant to finish assembling the machine if the motor has a internal problem, but I also find it hard to believe it is that messed up...

 

[Iron.Horse]

So I'm still not getting this fuel metering pump to seat. I've put PB Blaster down the hole and clean motor oil, tried turning the crank to all different positions while putting my finger down there to feel if the plunger is moving, and nothing. Is there anything to freeze up or break inside the motor that would cause this? The unit had an oil change/filter in 2019, and appears to have around 690 hrs on the clock. Compression is nice and tight. I even tried a different metering pump to make sure there was no difference. The only thing I can think of at this point is to actually run the machine on 3 cylinders or dead crank and see if the repetitive motion might jar it loose similar to an impact? I am just hesitant to finish assembling the machine if the motor has a internal problem, but I also find it hard to believe it is that messed up...

 

[Light in the Dark]

Maybe the tappet is stuck/unmoving. This is a gear driven front end, with the tappet riding right on the cam shaft, super simple setup. I would pull the problem pump position in question, and see whats down the hole. Spray and heat liberally.

 

[Iron.Horse]

Thanks Light in the Dark, I really appreciate it. I am quite sure you are right that the "tappet" is stuck. Do you think running the machine might loosen it up any? I did get the metering pump in, but only because the clamp is holding it down/depressing the spring. I am confident that I got it lined up correctly and the rack is moving, but I know that one at minimum is stuck, so it may just not push fuel to through that pump and to the injector. I definitely have soaking products in there...

 

[Light in the Dark]

I wouldn't. If its somehow broken or misaligned, you might end up doing more damage than you think. I really think high quality penetrants and heat are your friend here.

 

[Ray70]

Do you happen to recall how things were when you removed the #3 metering pump? Did it pop up that same amount when you removed the clamp?
I'm almost wondering if someone in the past somehow put 2 of the cups ( #6 in diagram ) in instead of 1.
I assume you've cranked the motor at least 2 full revolutions or more, and you aren't seeing any movement up or down?
If so the cam follower has to be stuck.
If you have a borescope I would try removing the #2 pump and get a borescope in there to look at lifter #3, perhaps you can see what's happening in there?

 

[Iron.Horse]

Hmm that's an interesting thought, I honestly don't remember how it came out, the rack was all sorts of jammed up and I was more concerned that someone put the pumps in wrong and bent it. I don't have a borescope, but maybe I can get creative. Are we talking about #6 in the diagram? I wasn't sure if there was a retaining system for the cups or whether they just floated in there.

 

[Ray70]

Correct, item 6. IIRC it is just sitting on top of the cam follower. You should be able to pick it out with a magnet, unless it's frozen in there.
If you didn't see any signs of rust or heavy carbon sludge when you pulled everything apart I somewhat doubt the follower or cup is frozen in there.
You can get a cheap USB borescope on Amazon for like $30 and plug it into a laptop.