1970 Perkins 4108 w/fuel system issues

[cmesiam]

I've been working on my fuel system for three weekends! I've replaced the Racor, 2 Micron fuel/water seperator (it was nasty) and the canister fuel filter on the engine (crappy design). Now unable to start. Have checked the fuel system over and over. (when manual pumping) fuel seems to be getting to the Injector pump but cant seem to get up to the atomizers (injectors). Is it possible to get gunk in the injector pump and now it's clogged? Ran fine till I changed out the canister filter on the motor. Please help!

Anyone ever pulled off the injector pump? How hard is that? How hard to get back on? Can it be cleaned on the boat by me? Or is that a mechanic job? Any advice would be greatly appreciated.

[Chief Engineer]

Did you bleed the injector lines at the injectors?

Any miniscule amount of air in the steel injection lines will be a no-go.

If the boat is in the water, make sure you drain the waterlift muffler.

If you fill that up the engine will not start.

[Minggat]

I did a filter change one time and wasn't careful about the gasket placement. When you say "crappy design", I remember saying the same thing. Spent a lot of hours doing just what you're doing. Then I took a closer look at what I'd done. It looked a lot less crappy when I got it right.

I had done the change out many times before. I don't know what I was thinking that time, but I screwed up. Hope that helps and it's not in your injector pump. If it does turn out to be your injector pump, it is not an easy change out. Talk to the pros. I have a spare I am willing to part with. PM me when you find out more.

Chief Engineer is right. You can fill up your exhaust pot with enough cranking and no starting. From there it can get worse than just not starting.

[Chief Engineer]

Also check and make sure you stop lever isn't pulled out. I must confess, it is good for the soul, I have done that. GRRRRRRRRRRRRR!!!!!!!!!!!!!!

[cmesiam]

Cheng,

Are you former Navy. I only know of certian times that a person calls themselve a Chief Engineer! I'm currently in the Navy, we can talk about that offline.

Yeah, again, I've been unable to get the fuel to the injector lines after the injector pump. I'm pretty positive that I've got the air out up to the injector pump. It appears that is as far as I can get it. The manual states to turn the motor (once up to this point) and it should squirt out of the lines near the atomizers. No joy! This is why I am suspecting the injector pump. Of course, it ran fine prior to my filter changing.

Yes, checked the stop cable.

I have no idea what the 'water muffler' is or how to drain it. I will look at that while I await your reply. Thanks

[Inthewind]

It's been awhile since I had one of those engines. I believe there is one or two bleeder screws on the side of the injector pump that will need to be bled of air by cracking them open. You may have to do it two or three times. Crack them open, turn the engine over while watching to see if air is escaping then retighten. I remember having that problem once but after removing the air from the injector pump, the engine fired up and ran fine.

[cmesiam]

Inthewind,

Appreicate the assist. Seems that I've done that SEVERAL times, to no avail. Any other ideas?

Thanks for the reply!

[Inthewind]

Seems you still have air in the system. Just to be sure, I am referring to a bleeder screw or screws on the side of the injector pump and not the steel fuel line connections to the pump. Just want to make sure you understand the bleeder screws on the injection pump. If you meant that you are just cracking the fuel lines open, thats not what I was trying to explain. If you did understand, than sorry for repeating myself.

[roberttigar]

You still have air in the system. There are 2 bleed screws on the pump. 1 on the body and 1 at the top-check the manual. Bleed those and then loosen the lnjector lines and crank the engine so a stream of fuel comes out.

Warning, if you crank the engine excessively with the seawater cooling line open, you stand a chance of getting water in the cylinders.
As difficult as the 108's are to bleed, the first thing you should do is shut the thru hull.

When all else fails, you can spray ether starting fluid into the intake, wait a minute and crank the starter. I've done it, its a bit scary, but it works.

There is a conversion for the final filter that adapts to a screw on type to eliminate the necessity to bleed. Bob

[slacker]

I know your frusteration! Heres what works for us.
Close the sea cock to the salt water pump.
Open the throttle 50%
Use the lift pump to get the fuel bled to the injector pump.
Crack open an injector
Crank the engine until you get air free fuel. Usually about 5 seconds
Close the injector and move to the next one.
Usually by the third injector the engine will start.
If it dosent just start over.

Caution. Dont be in a hurry. If it dosent start after about 5-10 sec of cranking at each injuctor allow the starter to cool off about 30 minuets before you try again.

After doing this at every filter change I installed a Walbro(StewartWarner) fuel pump between the Racor and the lift pump. Now all I do after changing either filter is turn on the pump, wait about 60 seconds then start the engine.

I wouldnt worry about the injector pump. Just get it bleed and I bet you will be ok.

Good luck to you,

[cmesiam]

All Concerned,

Thank you very much for your inputs. Again, I am not having any luck!

I have a WALBRO on order. That's exactly where I'm going to put it. Plus I'm adding a 10 MICRON filter in front of the RACOR. I intend to run the EC electric pump to a switch with a indicator light to remind me that I have it on! I ordered the pump and filter last week and havent recieved it yet.

Back to this Bleed system. Yes, I have cracked (and opened) every return fuel line from the Inj Pump, I have cracked (and opened) every vent screw on the body and top of the Inj pump. Again, there seems to be no fuel coming out of the (4) high pressure lines going to the atomizers.

What

[cmesiam]

Sorry get carried away!

What I'm thinking now is that the low pressure mechanical pump with the manual pump lever isnt working right?! It appears that when I am manually pumping it pumps only about 3 or 4 times before it acts like it's not pumping. Although I used it to fill the racor and the filter on the motor?!?!?

Folks, I'm beside myself on this one. Maybe I'll have better luck next week when I come out here with the other DC Electric pump.

I

[cmesiam]

I am very appreciative of the input you all have provided and hope to hear more. I'll keep you all posted. Thanks again,
Bruce

I keep hitting 'Tab' by mistake and sending the post. Hard to break old habbits! Sorry for the choppy posts!

[Chief Engineer]

Sometimes one gets things a bit out of order when bleeding.

I know, it has happened to me.

Check all hose connections on supply side
Prime Primary Filter
Prime Secondary with lift pump
Bleed Injector pump at bleed screws with lift pump
Open throttle to 2/3-3/34
Crack open injector lines about 1 turn
Using a remote start switch crank over engine
(I put strips of oil sorb under injector lines to absorb spills)
when fuel spurts close injector line.

Start engine...verify injector is operational by cracking each line while engine is running.

Some perkins have the return line going back to the secondary filter. It is not unususal for air to accumulate in the secondary.

Keep at it ....don't lose your cool.

BTW I am not former Military....Tugs/Yachts

Job Description?
1. Keep hot things hot
2. Keep Cold things cold
3. Make sure the engines go Suck-Squeeze-Bang-Blow
4. Keep the Ocean/Bay water on the outside.

[S/V Elusive]

While I have the Perkins 4154, I believe the injector pump is the same. All the above are correct, except I'm not a fan of using the engine to 'prime' things. I'm sure that you know where the lift pump on the engine is (where the fuel line comes to the engine), and I presume you know that there is a lever below it for manually pumping fuel to the engine. It IS a pain. As someone else mention (slacker), installing an in-line pump makes a lot of things easier.

Depending on where your secondary fuel filter is, that is usually the first 'bleed' point. There are, as previously mentioned, two bleed screws on the injector pump. You need to do them ONE at a time (closest to the incoming fuel line first). The bleed screw that is open, need only be open about 1 turn (if you open it more, you run the risk of bilge diving for the screw ... sigh..) . When you have good fuel flow, it will squirt nicely without bubbles with each squeeze of the priming lever.

Unless you have an electric priming pump (or fuel pump), then you may have to go the route of bleeding the injector fuel lines (from the injector pump), one at a time, by using the engine to crank and pump (although I've done it with the manual lever).

As mentioned in several threads on this forum, having a two micron primary is just going to cause you problems as it is probably going to clog frequently or cause you to replace often. You might want to consider 10 micron primary and the two micron on the secondary. You may also want to consider installing an in-line valve after the primary (and maybe before), so that you can prevent fuel from draining from the filter when you change out the element. This might help in your future.

Good luck!