Fuel Starvation After Upgrading Fuel Filter

[Snore]

I need some help with a diesel problem that popped up.


Installed a new Racor 215 with a 10 micron filter a month or so ago. Based on various posts, I purchased two 2-micron filters as spares. After reading that some people have a problem getting the factory filter off, I decided to remove the filter after only 10-15 hours. Since the original 10-micron was damaged when I removed it, I installed a 2-micron.

Went out today and had no issue going out the inlet. Off the coast I had the following problem- sailed for an hour or so in 1-3 maybe 4' seas and light wind. With a nasty squall approaching, I cranked up the engine. The engine stalled after running at 2,800 for about 30 minutes. Since it sounded like fuel starvation, I bled it at the high pressure pump. Cranked it up and continued to run off shore (no wind). Same thing happened while running at 2,800. After the squall passed, I removed and reinstalled the Racro, checked all fittings and made sure the secondary filter was tight. I bled it .... Again.... Outside the inlet, I fired it up and headed home at 2,000 rpm. No issues! Ran like a champ!

At that point I saw two possibilities 1) a vacuum leak small enough for the fuel pumps to keep up if the RPMs are low. 2) the lift pump cannot pull through the 2-micron filter if the RPMs are up.

Back at the dock in another squall.... I turned the engine off and waited 30 minutes. The engine started right up! It would appear that the fuel starvation was the result of the lift pump not pulling enough fuel through the 2-micron.

Any thoughts??

[Navatech]

Originally Posted by Snore

Any thoughts??

Do you have any vacuum/pressure gauges installed in your system?

[ranger58sb]

Originally Posted by Snore

At that point I saw two possibilities 1) a vacuum leak small enough for the fuel pumps to keep up if the RPMs are low. 2) the lift pump cannot pull through the 2-micron filter if the RPMs are up.

I think both are possible. Might also be related to what density your secondary filter is, and what the engine manufacturer has recommended for primary and secondary filter densities.

-Chris

[Cheechako]

most pumps do not "pull" as well as they push. The 2 micron could be your problem. As usual there are people with differing opinions on the 2 micron filters. Mine is you dont need that fine a filter and it will just clog faster and Murphy will make sure it's in a pinch. The easiest solution might be to change back and see if it cures the problem.

[laika]

Once you got out of the inlet and gave the 2micron filter a chance to catch some crud, maybe it plugged up enough to limit the flow at high throttle?

I ended up installing a separate polishing filter last year. I was going through those expensive Racor filters pretty regularly and my tank is very difficult to inspect and clean. The last straw was coming into Norfolk and having the engine starve while the boat drifted towards an aircraft carrier as I fumbled around below with the filter change.

FWIW, I use a large 1 micron filter with a low amp wabasto pump which cycles roughly the capacity of the tank each hour and returns to the bottom of the tank. 1 micron is way overkill, but maybe it will keep my fuel injection system that much cleaner over time?? Either way, 90% of diesel problems I've ever had have stemmed from fuel delivery, so the separate fuel polishing filter approach was to me an easy sell.

Of course, if you can just manage to keep your tank clean...

[Snore]

Guys thanks for the inputs...

The plan is to change to a 10 micro ....

Since there is only 8-10 feet of fuel hose in the system, I may change it all out of principle. The scrubber is in the long term plan ... But real estate in the Tartan 33 engine room is tight.

Thanks again