Lehman 120 priming issue - need help

Tried starting my engine today prior to launching the boat next week and engine would not start. It's not unusual after the winter for air to have entered the fuel system (not sure why by the way. Wasn't like that before but for the last couple of years I had to bleed the system in the spring). Anyway, tried pumping the little lever on the side of the fuel pump but it felt kinda loose and no fuel would come out of the bleed screws on top of the fuel filters. Decided to fill them manually with a small funnel to speed things up. Tried it again, no luck.

Any idea or suggestions?

Lift pump has failed. Cheap replacement at a tractor or industrial engine store. Carry a spare.

Or, open your fuel shutoff?

Sound like the fuel pump is sitting on the high of it's cam, turn the engine over a little and the lever should then work.

rochepoint said:

Sound like the fuel pump is sitting on the high of it's cam, turn the engine over a little and the lever should then work.

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That would be my guess. Just bump the starter.

Larry M said:

That would be my guess. Just bump the starter.

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rochepoint said:

Sound like the fuel pump is sitting on the high of it's cam, turn the engine over a little and the lever should then work.

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That's it

I put a electric pump from tank to filters, can hit switch and prime filters and pump, works every time. On switch that I just turn off , fuel flowers to engine just fine

Success! Thanks a lot guys. ?

And now you know.The simple things will get us all ever now and then.Glad you got her going.

Greetings,
Mr. F. If you ever have to "bump" the engine over again, one of these is cheap and easy...

Automotive Service Tool Sets - K-D Tools 124 Remote Control Starter Switch

You can get them cheaper. I think I paid about $12 for mine at Harbor Freight.

Is bumping the starter what did it?

Yep. I pressed the starting switch for half a second. Didn't work right away. Had to do it a few times until I felt the fuel pump "working". Then I was able to prime the line pretty quickly (filled the fuel filters ahead of time to avoid pumping for ever). The engine started right away after that.

Good deal! Glad you got it, and I have another "secret fix" that I'll probably forget when I need it...thanks for sharing.

Well, looks like this story is not over. Launched the boat yesterday and after 2-3 minutes the engine died. Spent over an hour trying to bleed the thing but it just wouldn't start. Even changed the not-so-old fuel filters just in case. No luck. I'm starting to suspect the fuel pump is dead because I was never able to make it work manually to bleed the line. Even after cranking the engine 25-30 times to get it to "engage". The little lever is soft and feels loose all the time now. I even removed the fuel line that comes out of the pump and cranked the engine to see if fuel would spurt out of the pump. Nothing came out (I'm assuming fuel would come out if the pump was working properly no?). I do have a replacement pump so it would be the next logical thing to try. Wanted to have your opinion first and maybe read about your own experience changing this fuel pump. Doesn't look too hard. Two bolts but one of them is a little hard to reach.

Can you rig a gravity feed bypassing the pump but still through the on engine fuel filters?

Don't need much, just enough to see if it starts...

Greetings,
Mr. F. Pumps aren't atrociously expensive and not hard to change. Not a bad idea to have a spare on board if, after change out, you find the pump was not the problem although it still may be the problem.
I changed a pump while the Admiral was doing circles just outside Port Everglades and inadvertently dropped one of the two 5/16-24 attachment nuts. Didn't have another on board and couldn't immediately find the errant nut. Ran on one nut to home dock and the local NAPA guy gave me 5 (I guess out of pity).
Hint: Hold the priming lever up while cranking the engine. You should feel pulsations.

Fotoman said:

... Wanted to have your opinion first and maybe read about your own experience changing this fuel pump. Doesn't look too hard. Two bolts but one of them is a little hard to reach.

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Not sure on the 120 but the 135 is OK but is easier if I drop the oil cooler first...

When you have the time, have you thought about adding an external electric fuel pump? 1-3 way valve, some proper electric for the pump, a couple of Ts and then bleeding the system or running on the DC pump and trouble shooting becomes easier. I know this doesn't help you today but...

RT Firefly said:

Greetings,
Mr. F. If you ever have to "bump" the engine over again, one of these is cheap and easy...Automotive Service Tool Sets - K-D Tools 124 Remote Control Starter Switch

Click to expand...

A friend who is a fitter and toolmaker, calls it an "inch button".

Tried to remove the pump today but didn't succeed just yet. I got the two nuts (had to grind a 1\2 inch wrench to make it fit where the rear nut is located. Otherwise the wrench is too wide and you can't turn the nut). But the pump wouldn't come out, it doesn't clear the studs. So my question is: do I have to remove the studs as well? If so, how do you do that? I tried to do it with the two nuts locked on the stud but it did work. Looks like the studs are a bit too short for the second nut to really engage in enough threads. Any advice would be appreciated!

Greetings,
Mr. F. Once you get the nuts off, the pump should just pull out. There's nothing on our engines that generate clearance problems. I think your pump should look something like this: It's actually upside down in this image...



One time on removal, a stud did come out inadvertently but I lock-tited it back in before putting the pump back on. Is there something in the way of your pump that is preventing a straight pull outwards? Maybe the internal lever (shown @ the 12 o'clock position in the above image) is hanging up on something. Push the priming lever up and down as you're pulling the pump away from the block or give the engine a quick turn. Maybe the internal lever is hanging up on the drive cam inside.

Thanks Mr. Firefly. There is nothing in front of the pump keeping it from sliding out. There was the oil filter but I removed that. It looks and feels as the internal lever is keeping the pump from coming out. Hence my question about the studs. I have the feeling that it needs to come out at an angle to allow for the internal lever to go through the hole. But the studs prevent that. I am a bit puzzled to read that you took yours out without removing the studs.

Greetings,
Mr. F. I wish I could be more explicit but I DID remove and replace a fuel pump without taking out studs....Oh, dear, to the best of my memory. Somebody help Mr. F out here. I'm not sure what day of the week it is...

Roll the engine over.

Apologies but could you be a little more explicit? Should I push the start button? If that's the case, should I screw back the nuts while I do this? Thanks.

Any more suggestions on this? I'm kinda stuck here.

Can you apply pressure on the pump (pull it away from the engine) while someone else bumps the engine starter a few times? It seems the cam is catching the lever just so and the studs wont let you angle it off the cam.

If nobody around then just a quick bump then check if the cam has moved enough to let the pump go.

If the diaphragm inside the pump is torn from old age it can cause fuel to leak into the crankcase so check the oil level for diesel fuel in the oil, no biggie just change the oil when the new fuel pump is on.

This should not be a difficult job. You will get it, no worries.

I would either roll it over manually or put the nuts back on if you are going to bump the starter.
I would not bump the starter with the pump hanging loosely on the studs. If it kicks the lever the wrong way it may bend the studs.

jleonard said:

I would either roll it over manually or put the nuts back on if you are going to bump the starter.
I would not bump the starter with the pump hanging loosely on the studs. If it kicks the lever the wrong way it may bend the studs.

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True and good point, Murphy is always around and it could even damage the cam.

So yes, remount the pump and be safe no need to jurry-rig it and get it all cobbled up.

jleonard said:

I would either roll it over manually or put the nuts back on if you are going to bump the starter.
I would not bump the starter with the pump hanging loosely on the studs. If it kicks the lever the wrong way it may bend the studs.

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Good idea! The manual control is important.

Ok, I will try that. I had the feeling that it wouldn't be a good idea to crank the engine with the pump being loose. That confirms my suspicion! I'd rather be extra safe than risk creating some internal dammges that would be hard to fix.