governor problem?

[fabricator]

OK, here is a long boring video, there is an example at the very beginning then a couple episodes toward the end, I don't know how to edit out the boring stuff.

[Horsepoor]

The video was insightful. I could help but wonder about the liquid fuel glimmering on the fuel pump. To me, this would imply a small leak and perhaps an air bubble entering the line every few minutes. Just my guess.

[fabricator]

No, the fuel on the pump was coming from the vinyl tube I was using as a "tank", I was pouring fuel into the tube and a fair amount ended up spilling on the outside, it behaves exactly the same way with the tube straight up in the air full of fuel as it does hooked up to the tank and filter.

[fabricator]

I've tried absolutely everything now, I ran it with the exhaust flange wide open, zero back pressure, the spill timing is perfect, I'm letting it sit shut down overnight and I'm gonna check the valve tappet clearance tomorrow, I don't see how that could affect this problem but what the hell.
The only thing that is consistent is that it always runs perfect for a while before it stumbles, then it will run perfect for a while before it stumbles again, but, it behaves the same with the regular tank or a vertical tube filled with fuel.
Sometimes it just loses 20 or 30 rpms twice it has quit completely.
When I had the exhaust flange off it was very apparent that when it slows down it's not firing at all, then the rack adds more fuel it really fires and blows black smoke.
So, I'm at a loss, is it possible it could be something with the internal governor weights? I don't know, I give up.

[XYZER]

I don't know, I give up.

Don't give uup...I loved your movie.....I just listened to it and enjoyed it....and see you have a well behaved governor in my opinion. I would bleed the injector line while it was running and make sure it is all uphill from the pump. You can get a small bubble in a high spot and it will run but it will be lacking the amount of fuel the bubble compresses and behave funny. I would try it. I have done mine.....just put on your safety glasses and crack it open with a wrench. Slowly tighten it let it build speed and repeat. There will be no big spay and cut you in two........just a dribble will come out from between the nut and tubing. But I still wouldn't stick my fingers around it......It is worth a try.......just spilt diesel....

[Ronmar]

I agree, the governor looks as if it is responding properly to the RPM droop...  Purging the HP line while running sounds like a good idea also.  I usually wrap a rag around the nut and wrench, the rag soaks up the fuel that bleeds off.

Following another thought, tell me a bit more about your setup.  Cooling system, Alternator, pully sizes, load it is connected to(all loads please) and voltage and amp draw during a typical run like in the video ect. 

Also what is your target RPM and how are you measuring it?  I timed and counted during the middle of that video while it was running stable, and came up with 100 firings/200 revolutions in 20.4 seconds.  The math works out to 588 RPM, but it was a little hard to count firing pulses past the valve noise... A vid with less valve noise would allow me to make a more confident RPM estimate...  If you are feeding a load and planning on 6 available horsepower but not making turns for it, a load change such as a electric radiator cooling fan cycling on and off or a load on the inverter cycling might be enough to exceed your available
HP at the reduced RPM...

[playdiesel]

Since you have allready done all the other things I would have tried first my "grabbing at straws" guess is you have a shard of some kind floating around in your fuel pump or injector that is hanging the delivery valve or poppet valve in the injector or they are hanging in the bores on their own and when the RPM drops enough to open the rack wide open it blows it out?  Were it mine I'd  have a 3/4 wrench ready and as soon as it slows down I'd hold the rack steady (so it doesnt go further open) and loosen the injector line on top of the pump. Fuel spurts or no will tell you where to look.

[billswan]

Fabricator I agree with ronmar the forum needs more info on load and the engine does sound somewhat slow.

But the following quote you wrote caught my eye.

When I had the exhaust flange off it was very apparent that when it slows down it's not firing at all, then the rack adds more fuel it really fires and blows black smoke.

So I read that as the engine is making smoke and then for several strokes you see no smoke then heavy smoke as it tries to cope is that right?

And you are positive the load is not dropping or partially dropping for a moment and then coming on hard?

Could be playdiesel put his finger on maybe a bad delivery valve?

Just thinking out loud trying to help.............

Billswan

[dieselgman]

Dale,

Your pump has 2 main wear components that are normally replaced on a pump rebuild. The plunger and barrel referred to as the pump element, and the delivery valve and its seat.
Both of these items must remain absolutely clean and are precision fit to each other to an extreme degree. These are not to be handled even with clean fingers for best results. They will easily slide within their mated parts with no stiffness or binding but a new item such as the element will require a wash of clean fuel and likely just a little break-in period. Both of these items are spring loaded so generally can recover from minor malfunctions. If either part becomes sticky due to imprecise fit or dirty fuel, then problems can begin with your pump. I believe that replacing (and re-timing) your pump with another replacement unit might help rule that out of the equation so I'll send one along.

dieselgman

[fabricator]

My plunger is a tight fit in the barrel, when it is pushed into the barrel it will not drop out on its own it has to be pushed out.

[fabricator]

Ronmar, I am belted to a Delco 27 SI alternator, my flywheel diameter is 23.35" and the driven pulley is 3.5" at 600rpms this is around 4000 rpms at the alternator, I am running into a 2000ah battery bank that hooks to an inverter that runs my water pump and freezer, I have the voltage on the alternator set at around 27.5 volts to keep the bank at float, there is also a wind turbine hooked to the bank.
Most of the time there is no load other than keeping the bank at float and I know this condition happens during these no load times
I slowed it down to 600 rpms to put more of a load on the roid, at higher rpms it was not even feeling it.

[fabricator]

Fabricator I agree with ronmar the forum needs more info on load and the engine does sound somewhat slow.

But the following quote you wrote caught my eye.

When I had the exhaust flange off it was very apparent that when it slows down it's not firing at all, then the rack adds more fuel it really fires and blows black smoke.

So I read that as the engine is making smoke and then for several strokes you see no smoke then heavy smoke as it tries to cope is that right?

And you are positive the load is not dropping or partially dropping for a moment and then coming on hard?

Could be playdiesel put his finger on maybe a bad delivery valve?

Just thinking out loud trying to help.............

Billswan

The answers are yes, yes and I'll check it out, believe me I appreciate any and all help.

[fabricator]

I don't know, I give up.

Don't give uup...I loved your movie.....I just listened to it and enjoyed it....and see you have a well behaved governor in my opinion. I would bleed the injector line while it was running and make sure it is all uphill from the pump. You can get a small bubble in a high spot and it will run but it will be lacking the amount of fuel the bubble compresses and behave funny. I would try it. I have done mine.....just put on your safety glasses and crack it open with a wrench. Slowly tighten it let it build speed and repeat. There will be no big spay and cut you in two........just a dribble will come out from between the nut and tubing. But I still wouldn't stick my fingers around it......It is worth a try.......just spilt diesel....

It is all uphill from the pump, all fittings are flare fittings with hard lines, no hose clamps, I'll try bleeding while running, I've spilled so much diesel this week another fifty gallon or so won't be a big deal. LOL

[fabricator]

Since you have allready done all the other things I would have tried first my "grabbing at straws" guess is you have a shard of some kind floating around in your fuel pump or injector that is hanging the delivery valve or poppet valve in the injector or they are hanging in the bores on their own and when the RPM drops enough to open the rack wide open it blows it out?  Were it mine I'd  have a 3/4 wrench ready and as soon as it slows down I'd hold the rack steady (so it doesnt go further open) and loosen the injector line on top of the pump. Fuel spurts or no will tell you where to look.

I'm game for anything at this point.

[dieselgman]

I would also comment that for purposes of engine break-in you should try and add some loads and work it fairly hard. A resistive load in the form of small heating element is probably the easiest to manage and control. Running it very lightly or intermittently loaded may result in other problems with things like ring-seal. Get that engine hot!

dieselgman