Reviving a comatose Lehman

[ronobrien]

Thinking what I might do next is to temporarily wire the starter button to down below next to the temporary fuel tank. That way I should be able to crank it over while keeping fuel pressure to the IP via the fuel bulb. this I think should rule in or out the lift pump. I do have an inline fuel pressure test gauge, but like any other tool that I need right now, it's an eight hour drive away.
Keep thinking that there is something that I am missing in the engine's signs/symptoms that would point to the problem.
One of the local lobstermen has a two inch thick workshop manual for these engines which he will loan to me later today. Consensus at the town dock this morning was to check the injector timing in case it slipped. Also to look inside the IP to be sure that the throttle is indeed advancing the fuel rack.

I have been in situations where something is being missed, obviously, you just don't know what that is. The advice to check throttle and IP timing is sound. When the problem is elusive you can't assume anything, including the work you have already done. Start at the very beginning and execute the diagnostic tree again. Speaking of which, a diagnostic tree is a good document to use as you go. It is possible that when you see the diagnosis laid out in this format you can see connections or patterns to the problem. These problems can be frustrating. Best of luck

 

[C lectric]

I am not a Lehman guy but in general the large nut needs to be HELD in place with a wrench while the smaller nut that actually secures the pipe is turned. If the small nut alone is twisted it may cause the large one to move also which can damage the pipe end by twisting it.

 

[N97746]

Another update. Following advice, checked the injector pump timing. Much easier said than done on my particular engine setup.
With the engine set between deep engine beds and a drip pan tight to the engine there was no access to visualize the timing marks on the flywheel.
I could slide my hand down and with my fingertips just feel the opening in the bellhousing. Seemed that the cover was already off. No combination of mirrors or lighting would let me see the hole, much less inside it.
So ended up pulling the #1 injector. Put a thin rod in the injector hole and after a few revolutions was pretty comfortable I had TDC on the compression stroke. As it turned out there was a hole drilled in the lip of the pulley that lined up with a mark that had been made on the cam cover when at TDC.
I used a thin flexible steel tape to measure the circumference of the pulley. Divided that number by 360 and got the distance between degrees. Multiply that number by 20 and it came out to just a little after where a -22 had been inscribed on the pulley.
Pulled the inspection port on the IP and checked for the timing "dimple". Nowhere to be found. Rotated the engine and found that the timing dimple aligned with the notch when the engine was at 80 degrees BTDC.
As soon as the heat breaks a bit I'll go back down, pull the IP and set the timing. Hoping that this fixes the problem.

 

[ronobrien]

Kudos for the ingenuity and hard work. Best of luck.

 

[N97746]

Well I think the problem is fixed. I pulled the injector pump, rotated the gear until the timing marks lined up, then turned it back a little more to accommodate the movement of the IP gear when it meshes with the helical cam gear. When the IP was mounted the marks remained lined up. I rotated the crank by hand several revolutions and the timing marks stayed lined up.
Bolted everything back together, re-bled the system and tried the starter.
Fired up after about three revolutions and settled into a nice smooth idle. Cycled it on and off several times. Now will always smoothly catch and idle after less than two revolutions.

I guess what I learned through all this is to maybe not trust everything you are told regarding the prior history of your boat and if ANY doubt check EVERYTHING.

Many thanks to Brian at AD and everybody that chimed in with advice.

 

[RT Firefly]

Greetings,
Mr. N. Good news! A quote that is apropos from one of my favorite authors:

https://quoteinvestigator.com/2017/06/23/half-see/

Doubly appropriate IMO as it penned in a hospital for the mentally ill...Boating IS fun eh?

 

[Nick F]

So, help me here . . . what is the bottom line? Was it the injection pump timing that needed correcting?
Thanks in advance

 

[ronobrien]

Well I think the problem is fixed. I pulled the injector pump, rotated the gear until the timing marks lined up, then turned it back a little more to accommodate the movement of the IP gear when it meshes with the helical cam gear. When the IP was mounted the marks remained lined up. I rotated the crank by hand several revolutions and the timing marks stayed lined up.
Bolted everything back together, re-bled the system and tried the starter.
Fired up after about three revolutions and settled into a nice smooth idle. Cycled it on and off several times. Now will always smoothly catch and idle after less than two revolutions.

I guess what I learned through all this is to maybe not trust everything you are told regarding the prior history of your boat and if ANY doubt check EVERYTHING.

Many thanks to Brian at AD and everybody that chimed in with advice.

This was my point in an earlier post about using a diagnostic tree. When the problem becomes elusive, your best strategy is to go back to the beginning, develop a written diagnostic tree and follow & verify every step. Kudos for creativity and perseverance.

 

[BCRyan]

Congrats and a very satisfying story in the end. Thank you for sharing!!

 

[TowLou]

Nice job. Timing can get very tricky. Have had many of head scrachers because of that.

Just glad those pumps had a mark where some you have to have a shop set it to TDC and lock the pump till it is installed.

 

[N97746]

Responding to Nick, yes it seems that the out of time injection pump was the primary problem. That said, the time I spent setting up a new fuel delivery/filter system did correct other peripheral problems.
I think I missed a big clue. Early on after several failed starts there was a fine cloud of white vapor coming from the exhaust. Unburned fuel. this should have told me that there was fuel being delivered to the injectors. I knew I had air and compression and obviously fuel, but at the wrong time for combustion.

One suggestion I would have is, by using the flywheel marks if at all possible, accurately mark TDC and 20/22 degrees on the front pulley. That way if you ever feel the urge to check your IP timing it should only take a few minutes.