Engine Stalling

[IG 30]

Hi All, Im wondering if anyone can give me ideas on what's happening with my motor, I have a IG 30ft with a Ford Lehman 120hp model 2715E, The issue is that it stalls on me as if its run out of fuel, yesterday we went for a slow cruise around the lake running for around 3 hours at 10,000 rpm;s stopped done a little fishing then re-started and headed for home, however as soon as I slowly added revs it started loosing power and even throttling on it just lost power and stalled, it would not go again, plenty of fuel, I loosened the bleeder on the secondary filters and pumped fuel up. With the wife cranking the engine and a little help from easy start she was up and running again and got home with no further problems. This is now the 2nd time this has happened so wondering if anyone has had a similar issue, is it filters or blocked breather.... Thanks

 

[Comodave]

I assume you meant 1,000 RPMs. It sounds like you have an air leak in the fuel supply. Check all connections in the fuel supply. Especially the on engine secondary fuel filters, they have a reputation for air leaks. They have what sort of looks like O rings but they are actually gaskets and can be installed improperly. Also make sure that one was not left in from the last filter change so now you have 2 instead of 1 in the filter. It is easy to miss when changing the filter. Good luck.

 

[High Wire]

If bleeding the air out "fixed" the problem, then it is air leaking in. The usual suspect is the primary fuel filters between the fuel lift pump and the fuel tanks. These filters are under some vacuum. Has anyone changed primary fuel filters lately?

 

[IG 30]

Hi Thanks, the filters are being changed this week, both the separators and the secondary filters

 

[Comodave]

Hi Thanks, the filters are being changed this week, both the separators and the secondary filters

Are you doing it or having it done? If you are having it done suggest you be there and watch how it is done. This is something that every diesel owner absolutely needs to know how to do. So if you are having it done this is a good opportunity to learn how to DIY, assuming the mechanic doing it actually knows how to do it.

 

[Portage_Bay]

With the wife cranking the engine and a little help from easy start she was up and running again

If easy start is starting ether do be careful with that stuff. Best mechanic I know calls it "rebuild in a can". When I said ether doesn't rebuild an engine he said "No. I do after you use it!"

 

[IG 30]

Hi, Yes I am going to do it myself, its been a very long time but I use to own and run a tip truck and small bull dozer and was always having to bleed them both. I agree the hands on approach is the only way of learning and understanding the workings of the boat.

 

[Comodave]

If you are going to use starting fluid, don’t spray it into the intake, that is asking for disaster. Spray it on a rag and hold the rag to the intake so there isn’t a slug of fluid going into the engine.

 

[C lectric]

I agree about the problem being caused by an air leak.
Did it just start this stalling?
If so then what was the last thing done in the E.R.?


I also agree that ether use should not become a habit. Fix the problem or you will have far more serious trouble with engine damage.

If the engine needs a helping hand something like WD40 is far more friendly to the engine but should not be considered unless a real emergency.

 

[RT Firefly]

Greetings,
Mr. IG. What everyone has suggested so far AND perhaps your fuel line has de- laminated and the inner tubing is collapsing and blocking fuel flow at higher RPM. I've had it happen twice and it also happened to a friend.
Hose looked fine from the outside but that tricky devil had gone for a shyte on the inside.

 

[Comodave]

Greetings,
Mr. IG. What everyone has suggested so far AND perhaps your fuel line has de- laminated and the inner tubing is collapsing and blocking fuel flow at higher RPM. I've had it happen twice and it also happened to a friend.
Hole looks fine from the outside!

Another real possibility. I have never had it happen but it would be a bugger to find...

 

[C lectric]

Actually you might get a a warning of trouble if the fuel system had a vacuum guage installed.
But yes, that is a possibility.

 

[rgano]

I had twin Lehman 120's and did run into an air ingestion issue on one. Luckily I had a small Facet "priming" pump installed in the fuel system before the first Racor filters, and all I had to do was fire that baby up and flip the bypass valve around it closed to pressurize the fuel delivery system. Then, if you have the Simms injector pump, use a 1/2-inch box or open end wrench on the bleed screw on the side of that pump (see the manual) to bleed the air. The engine will start right up without the need for any ether. The final solution to my air ingestion issue was to replace a crimped o-ring under the Racor filter's tee-handle. That Facet pump came in handy so many times...

 

[catalinajack]

Many years ago (50?) My father witnessed the owner-operator of a D8 Caterpillar dozer blow the head off his engine using ether in the dead of a New England winter.

If you are going to use starting fluid, don’t spray it into the intake, that is asking for disaster. Spray it on a rag and hold the rag to the intake so there isn’t a slug of fluid going into the engine.

 

[FF]

MY guess , vapor lock.

Heat in the engine space is enough to boil the fuel , so after being stopped and restarted there is not air but vaporized fuel in the feed line.

Perhaps running the blower might help.

A water wet rag on the fuel line before engine restart might also help.

 

[catalinajack]

This from the BP website. "At elevated temperatures, diesel fuel will begin to vaporize and become ignitable with an open flame. The lowest temperature at which the vapor will ignite is the fuel’s flash point. Diesel fuel #2 as specified by ASTM D975 has a minimum flash point of 125.6°F"

MY guess , vapor lock.

Heat in the engine space is enough to boil the fuel , so after being stopped and restarted there is not air but vaporized fuel in the feed line.

Perhaps running the blower might help.

A water wet rag on the fuel line before engine restart might also help.

 

[psneeld]

I wonder what the vapor pressure and how it affects flash point is with a vacuum on one side of the lift pump and pressure on the other?

 

[northernmist]

Had the exact same problem with my Lemans. The small rubber line ( in my case it was metal chain protected) just before the pump, would collapse, preventing fuel flow, then open shortly after the motor had stopped. A VERY common occurrence with many manufacturers. Easy and cheap fix to replace all rubber fuel lines- then you do not have to search . Good luck!

 

[JESSEDIVER49]

Could be the lift pump. I had a similar sounding situation with my port side Lehman 120 8 years ago. It ran for about 2 hrs and then quit. I manually repriimed and it ran again for 2 hrs and quit and so forth. Switched out the lift pump and problem solved. The mechanical arm was worn/pc broken and not allowing full strokes, only partial.

 

[jleonard]

Had the exact same problem with my Lemans. The small rubber line ( in my case it was metal chain protected) just before the pump, would collapse, preventing fuel flow, then open shortly after the motor had stopped. A VERY common occurrence with many manufacturers. Easy and cheap fix to replace all rubber fuel lines- then you do not have to search . Good luck!

Happened to me also. Very common problem.

 

[Pop seas]

I had a similar problem with my 120 Lehman. Turned out the problem was the fuel line intake connection at the bottom of the fuel lift pump had the wrong fitting installed so it would not seal properly. Result was the fitting would vibrate loose and then the fuel pump would suck in air and fuel (fuel would never actually leak there though) and gradually I would end up with an air lock and engine stall. American Diesel sells the proper fitting for this which is longer than a standard fuel line fitting and is a specialty part for a Lehman. If yours has a fitting where the nut part of the fitting tightens right up against the bottom of the fuel pump you have the wrong fitting. The American Diesel fitting allows the tapered sealing end of the fitting to get a good seal inside the fuel pump. Cheap and easy fix.

 

[RT Firefly]

Greetings,
Welcome aboard, Mr./Ms. Ps.

First post in 7 years????

 

[new2trawl]

Change your fuel lines at the same time you change both primary and secondary filters. I run twin Racors for primaries, each set off engine, with secondaries on engine. Ensure any rubber lines you use are firm with a nylon braid in the wall. You shouldn't have any heat concerns until you get to the engines. Just be sure to strap the lines away from heat sources leading up to lift pump, particularly from pump to secondaries. Try to keep lines for contacting the engine block. I've had good success bleeding air through the injector pump (priming lever at up-lift) but not to the injectors on my 120s. I end up loosening each line at the injectors to bleed out air while cranking the engines in the room with a remote switch. As soon as fuel is pressurized out of the line, I tighten the nut while still cranking. Be careful not to over tighten the nut. These lines are machine-sealed, no gaskets.
Also, I saw where you run them at 1,000 rpm, maybe not all the time? These tractor motors need to run close (around 2300) to WOT periodically, for about 1/2 nm. Keeps them 'healthy'.

 

[SoWhat]

It could be either fuel starvation or air infiltration. In my case I air locked the high pressure pump. I blew out each line with compressed air then bled at the injectors. Problem solved.

It is easy to get a poor seal when installing new cav secondary filters. It is also easy to miss a cracked rubber hose in the shielded hose running out of the fuel pump. Have had both.