Lift pump on TAMD41A Penta

[petrolhead63]

HI, I have the early non sealed lift pumps on our engines and when going to check them inside this weekend working through potential reasons for a drop in performance I noticed the lids are on different way round on each engine.....perhaps somebody would know which is correct

The lid has a pressed down dimple on one side, and a letter R on the other. It can be fitted I think either way round on the two screws because it is symetrical.

Also where is the strainer on it....I expected to see a mesh on the top but it has only a rubber seal affair solid on one side. There is no exploded diagram in my manual. Is there a small gauze strainer in the fuel feed pipe to it?

Many thanks.

 

[snowbird30ds]

There should be a strainer inside like a thimble off to one side of the pump under the seal, the dimple on the cap is there to hold the strainer down to seal the underside, if I remember correctly the strainer was to the rear of the pump (inside), like you when I checked mine I was expecting a mesh across the top in the open part of the seal.
Mine are TMD41a's but should be the same pump.
On mine I had to carefully scrape a layer of fine crud from the mesh sides of the strainer (it should come up whiteish) and could suddenly get full throttle again, just changing the pre-filter didn't do the job, I have been getting crud and rust in my pre-filters all this year so need to tank the tanks out and get new stainless ones made (also found a weep at the bottom of one) unfortunately that means taking the engines out.

 

[petrolhead63]

Wow thanks, I shall look again. We have been down on power and working through. The boat was a 1 owner for 26 years and had sat a bit due to his getting older. After our 1st really lumpy trip to Weymouth we lost lots of power and both pre filters were totally blocked with black gunge.
All changed, and tanks cleaned out etc and no more issues on pre filters. However power is still bit of an issue, its like fuel starvation as no smoke and hence why I thought strainers in the lift pump somewhere could be old, nasty, partially blocked after 30 years!
I may even have new parts in my spares box..so will look and i now know what the dimple does!
That seal is strange too....brick red rubber sealed over one side and a hole in it the other side.
The strainer I guess is under the sealed side hidden perhaps.
fortunately our royal storebro has stainless tanks!
I have done plenty, new exhaust hoses, intercoolers cleaned and modded to later better tops, heat exchangers stripped, cleaned, all new fuel hoses made up etc.
All I have left is to service injectors which I think is overdue and check out the turbo's on the "big" planned maintenance.
Thanks for your input...if a little strainer gets back full throttle/power I will be a happy chappy...............

 

[snowbird30ds]

Let us know if it makes the difference, the seal peeled off easily enough when I did mine and went back fine with no leaks.

 

[petrolhead63]

I will, it could be a few weeks before testing and I will look in at the exhaust side of turbos too...fearing the worst! I am guessing I should not need to bleed the engines after only messing with the lift pumps, the little air introduced will self bleed because the filters before and after the lift pump will be clear of air.
Injectors was my other worry...near 30 years old, no knowledge they have ever been serviced but I would expect lots of smoke if they were the issue...too much diesel rather than not enough.

 

[snowbird30ds]

If it runs ok and doesn't chug out plumes of black smoke I would leave the injectors alone, if it aint broke and all that.

 

[petrolhead63]

Yes I know what you mean and usually agree other than when preventative maintenance can be wise, I have been told from more than one source that the nozzles on those injectors are prone to falling out and into the engine when they are clapped or old.... That worries me a little and a refurb would remove the worry although also a hefty chunk of hard earned!

 

[petrolhead63]

Let us know if it makes the difference, the seal peeled off easily enough when I did mine and went back fine with no leaks.

Well, I have been working more on the old girl. Checked turbos and they look ok to me though I am not an expert.

To the lift pumps, the strainers have previously been removed..not there!

As it happens I have seal and strainer kits in my spares box but decided not to fit any yet and introduce something else in the system until I feel happier it is running right.

I have no exploded diagram in manuals, the seals have a close side and open side for the two chambers of the pump. I think the open seal side is on the inlet/strainer side because there is a little upstand on the strainer to coincide with the dimple on the lid. I do not think a thick rubber seal would sit between these? The seals were different ways round on each engine from previous owners!

Thanks