PERKINS 4108 CRUISING ALONG THE RIVER AND JUST STOPPED PLEASE CAN ANYONE HELP

[deblen]

Remove deck fuel filler cap. If that cures it,your fuel vent is clogged.

[Cheechako]

Originally Posted by deblen

Remove deck fuel filler cap. If that cures it,your fuel vent is clogged.

Yes, another good option. Mud Daubers clogged my vents in a few months in florida.

[tinkrman69]

do you get fuel at the injector end of the fuel pipe whilst cranking the engine? when you bled the fuel system did you bleed the top vent on the governor housing...top of the injection pump. if you have fuel every where whilst priming and no fuel at injectors whilst cranking I'd think the quill shaft on the injector pump broke. If you have a fuel pressure sensor on the pump I'd check that too, could be bad causing the fuel solenoid to cut off.

[Jason Flare]

A lot of good advice here.

Also, I have had my 4-108 shut off like someone pulled the fuel shutoff lever. In my case it was a small air leak at the lift pump.

The first thing I learned online when searching for an answer to how to bleed a 4-108 is that few people change their fine filter because 4-108's are a bear to bleed.

Here's where I'd steer:

1.) Make sure you have fuel to your primary filter. If no fuel there, look for a plugged tank vent or plugged pickup tube. Be sure both tubes are free flowing.

2.) Make sure you have fuel coming out of your primary filter. In my case I installed an electric fuel pump after the primary filter. I use that pump to determine that I'm drawing fuel from the tank, through the primary filter and to the pump.

3.) The next place to check is fuel flow through the lift pump and through the fine filter. That bleed screw is my 4-108 is at the top of the filter. This was where I finally found my problem was. I had fuel flow to run the engine for about 70 seconds, (After bleeding injection pump and injectors,) but I noticed a tiny fuel leak on the fine filter and tightened it a bit. What I didn't realize for awhile was that I had reduced fuel flow through the fine filter even more, to the point of not getting enough fuel past the fine filter to run the engine. Be sure you have good fuel volume through the fine filter!

4.) Once you have good fuel flow through the fine filter bleed the points farther down the line. There's a good video online that I'll find and post a link to on how to bleed a 4-108. If my memory serves me correctly you need to bleed the governor screw on top of the injection pump. For me that required a 1/4" ratchet, a long 1/4" drive extension, then a universal joint and the correct size socket.

The next bleed point is on the side of the injection pump. I used an 8mm open end wrench to crack that open. ( The 8mm fit better than the 5/16")

I believe the order is, bleed the 8mm/ 5/16" bleed screw on the side of the injection pump. Close it up after good fuel flow and no air. Then bleed the governor. ( The nut on top with socket and universal joint. Get good fuel flow and no air and close that up. Next, follow the pipe from the fine filter to the injection pump. Loosen the nut where the pipe enters the injection pump. Get good fuel and no air.

5.) Next crack open all four nuts on the pipes entering the injectors. Turn the engine over using the electric starter. (Be sure your raw water seacock is in the off position!)
In a few seconds the pipes at the injectors will start spurting air a fuel. Give them a few seconds, and begin tightening the nuts on the pipes, starting with the injector spurting the largest volume of fuel and working your way down the line.

6.) The engine will start. Turn on the raw water seacock.

I'll go look for that YouTube video on bleeding a 4-108 and post it here.

This is probably the video:

https://m.youtube.com/watch?v=PwaSAGGTnco

This and the Perkins manual was enough for me.

Here's the 4th in a series of videos:

https://m.youtube.com/watch?v=amNSQUtMBuE

There are few things nicer in life than cracking the injectors, getting fuel and snugging them up to the sound of a 4-108 ticking away.

Also, don't run your electric starter for more the 35 seconds every several minutes. Let it cool down.

[puffcard]

Have had the engine stop cold, once from the lift pump failure and twice from pickup tube blockage.

[leftbrainstuff]

Fuel problem is the obvious first thought.

Neutral start switch and low oil pressure cutoff fault are less obvious but potential candidates.

What changed before the stoppage?

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[Jason Flare]

Originally Posted by leftbrainstuff

Fuel problem is the obvious first thought.

Neutral start switch and low oil pressure cutoff fault are less obvious but potential candidates.

What changed before the stoppage?

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

At this point, after the stoppage the OP changed the filter. If he changed the fine filter he has a fuel issue to settle possibly in addition to the other issues you mention.

PS My old 4-108 doesn't have a low oil pressure cutoff or a neutral safety switch. Less to go wrong for me!

[Cheechako]

Originally Posted by Jason Flare

A lot of good advice here.

Also, I have had my 4-108 shut off like someone pulled the fuel shutoff lever. In my case it was a small air leak at the lift pump.

The first thing I learned online when searching for an answer to how to bleed a 4-108 is that few people change their fine filter because 4-108's are a bear to bleed.

Here's where I'd steer:

1.) Make sure you have fuel to your primary filter. If no fuel there, look for a plugged tank vent or plugged pickup tube. Be sure both tubes are free flowing.

2.) Make sure you have fuel coming out of your primary filter. In my case I installed an electric fuel pump after the primary filter. I use that pump to determine that I'm drawing fuel from the tank, through the primary filter and to the pump.

3.) The next place to check is fuel flow through the lift pump and through the fine filter. That bleed screw is my 4-108 is at the top of the filter. This was where I finally found my problem was. I had fuel flow to run the engine for about 70 seconds, (After bleeding injection pump and injectors,) but I noticed a tiny fuel leak on the fine filter and tightened it a bit. What I didn't realize for awhile was that I had reduced fuel flow through the fine filter even more, to the point of not getting enough fuel past the fine filter to run the engine. Be sure you have good fuel volume through the fine filter!

4.) Once you have good fuel flow through the fine filter bleed the points farther down the line. There's a good video online that I'll find and post a link to on how to bleed a 4-108. If my memory serves me correctly you need to bleed the governor screw on top of the injection pump. For me that required a 1/4" ratchet, a long 1/4" drive extension, then a universal joint and the correct size socket.

The next bleed point is on the side of the injection pump. I used an 8mm open end wrench to crack that open. ( The 8mm fit better than the 5/16")

I believe the order is, bleed the 8mm/ 5/16" bleed screw on the side of the injection pump. Close it up after good fuel flow and no air. Then bleed the governor. ( The nut on top with socket and universal joint. Get good fuel flow and no air and close that up. Next, follow the pipe from the fine filter to the injection pump. Loosen the nut where the pipe enters the injection pump. Get good fuel and no air.

5.) Next crack open all four nuts on the pipes entering the injectors. Turn the engine over using the electric starter. (Be sure your raw water seacock is in the off position!)
In a few seconds the pipes at the injectors will start spurting air a fuel. Give them a few seconds, and begin tightening the nuts on the pipes, starting with the injector spurting the largest volume of fuel and working your way down the line.

6.) The engine will start. Turn on the raw water seacock.

I'll go look for that YouTube video on bleeding a 4-108 and post it here.

This and the Perkins manual was enough for me.

Here's the 4th in a series of videos:

There are few things nicer in life than cracking the injectors, getting fuel and snugging them up to the sound of a 4-108 ticking away.

Also, don't run your electric starter for more the 35 seconds every several minutes. Let it cool down.

It's funny how different people have vastly different experiences. My Perkins 4-108 was so easy to bleed it really didn't need it. Just cracking the last injector in line is all I ever did. Never even looked for other fittings. The damn engine was hard to NOT START. If you wanted to just crank it for a second, it wanted to start. I think I was just very lucky with that engine. Everyone talks about oil leaks too, I never had one, not one drop. Go figure.... :>)

[Jason Flare]

Originally Posted by Cheechako

It's funny how different people have vastly different experiences. My Perkins 4-108 was so easy to bleed it really didn't need it. Just cracking the last injector in line is all I ever did. Never even looked for other fittings. The damn engine was hard to NOT START. If you wanted to just crank it for a second, it wanted to start. I think I was just very lucky with that engine. Everyone talks about oil leaks too, I never had one, not one drop. Go figure.... :>)

Very true for me too. Almost always runs like a bear and easy to bleed.

But things went south for me and I knew I had air past the fine filter and into the injection pump. I had to get all the air out and the process had to be followed.

[topmast]

Must be short sighted of installers to not send the return fuel back to tank. Putting it back into the line doesen't allow bubbles from minor leaks or insufficient bleeding to escape.

[Jason Flare]

Originally Posted by topmast

Must be short sighted of installers to not send the return fuel back to tank. Putting it back into the line doesen't allow bubbles from minor leaks or insufficient bleeding to escape.

I'm not sure what you mean. I have a return line to the tank.

[topmast]

Good Jason ,as it should be. A show of hands? how many have a line from the injectors back to the input of the filter?

[Jason Flare]

Originally Posted by topmast

Good Jason ,as it should be. A show of hands? how many have a line from the injectors back to the input of the filter?

What might be confusing is that the return line arrives at the top of the fine filter with a banjo fitting and then exits and returns to the tank. It looks like the return line enters the fine filter but it does not.

What is confusing is that this banjo fitting is also the one you crack to bleed the fine filter but if you look at it closely you'll see that it's a pointed plug type screw. You can bleed the fine filter by loosening it but the return fuel follows the banjo fitting to a line back to the tank.

I hope to now post a picture. If I'm able, A is the fitting I'm referring to:

https://www.google.com/search?q=4-10...y7PxMnbThmM%3A

[tinkrman69]

My return line goes to said Bango fitting at the top of the fine filter and on the other side of it a line goes to the tank. But the bolt has a hole in it and fuel can also go back into the filter. When I change the filter I can just loosen the return line at the bang fitting to fill the filter. no other bleeding necessary.

If I get a lot of air...ie...fun out of fuel of bad leak...I fill the filter crack one of the hold down nuts on top to the governor housing till I get fuel then I crack two high pressure lines at the infector nozzles and crank till I get fuel tighten and she cranks and smooths out in less than a minute. Using the manual has too many steps. I put a primer bulb before the primary filter as it pumps more than the teaspoon per stroke of the lift pump. An electric pump would be easier. The primer bulb isn't made for diesel fuel so I replace it once a year. It would take ten or more to equal the cost of and electric pump. and if that goes... well that sucks;=)

Well poppy did you figure out what went wrong? Let us know.

[Jason Flare]

Originally Posted by tinkrman69

My return line goes to said Bango fitting at the top of the fine filter and on the other side of it a line goes to the tank. But the bolt has a hole in it and fuel can also go back into the filter.

Well poppy did you figure out what went wrong? Let us know.

I could be wrong because I'm often enough wrong, but look at the bolt closely. The hole is to feed the banjo fitting. There should be no hole down the length of the bolt that could feed the filter. The end of the bolt should be tapered or conical to provide a plug at the top of the fine filter.

BTW that's a good way you've got to fill the filter. Hadn't thought of that. Thanks.

Poppy, I, for another, am waiting anxiously.

ETA: On second thought, filling the filter from the bleed port may be a bad idea since you'd be filling it with unfiltered fuel that would then go, still unfiltered, to the injection pump.