Lucas CAV pump

[Mistress]

Please see my post on the general board (Diesel owners' board sticky).

I'm not reaching full RPM unloaded or loaded (2300+ engine loaded, 2600+ unloaded). Spec is for 2850 unloaded, 2600 loaded.

Here's a pic of the pump. You can see the new low idle screw. High idle screw to the right:

Any reason I can't unwire the high idle screw and get more at no load...then see what I get with a load?

[Geo]

Mistress, I saw the picture of your injection pump. You are right it is a fuel shut off lever. It can be manually operated or with a cable. No it does not replace the selonoid. There are two types of selonoids.
CAV 12 volt actuate to stop
CAV 12 volt actuate to run
You can check which one you have by turning on the ignition key and listen for a click of the selonoid. This would be the actuate to run selonoid. Or pull the wire off, engine will not start. Sorry I can't help you with the RPM's

[Mistress]

I have the Cummins operation/maintenance manual. It doesn't break down the CAV at all.

I'm gonna play with the high idle screw in back of the throttle valve. That's #3 listed in the troubleshooting flowchart in the Cummins book anyway. Ya..it's wired, but I'm long out of any warranty anyway.

If I can get full rpm at no load, then I'll check with load and go from there.

[Pedlyr]

Mistress-

I assume you have an aftercooler and turbo. If the aftercooler is dirty or the turbo is screwed up, then it can affect RPM's as well.

Any smoke in the exhaust?

[Anonymous]

6bt/210

Have turbo..no aftercooler...no detectable smoke throughout the rpm range or at start up, throttle up, etc. Should get smoke if turbo is weak/bad.

[Pedlyr]

No smoke should rule out alot of things, including the turbo, but I always still like to check the boost pressure anyway. I think it should be in the mid 30's for a Cummins 6b.

I would try a cut-out test to also make sure each cylinder is firing correctly.

There also should be a timing mark on the side of the pump. It is usually on the housing where the top left mounting stud bolts on. Sometimes this can be off. Worth a look.

[skipm]

Mistress I didn't check the other post what is your prop size?I have a 1992 26' cc proped 16 L 15 & turn 2800 wot cruise @22+kts@2200.I'll take a pic of my pump I believe it has more throttle swing than your showing.I have 800 hrs on my 6b just had to repair a weeping banjo fitting on the hi pressure side of the pump,& my idle much smother.

[Mistress]

16L x 17.

700 hours on 6BT.

Very slight weeping at 2 injectors (where high pressure feed is).

Idles fine, runs/starts great. Just low on rpm even at no load.

[SSJULZ]

Have you checked you fuel filter? When is the last time it was changed? Sometimes a dirty fuel filter will cause this kind of problem. At least with my truck it does and it's a Cummins too.

[Anonymous]

Changed them today...they looked pretty good. Had a 2 micron folter in the Racor. Spin-on should last forever with that. Changed them both anyway. No difference on hose.

Opened the high idle screw up a turn...pushing 2800 now. We'll see if I get more on the water.

[Anonymous]

Had a 2 micron folter in the Racor. Spin-on should last forever with that.

The 2 micron filter in the racor fuel/water sep could also be your problem. That is supposed to be a 30 micron filter!! The secondary (engine) fuel filter should be somewhere in the 5-10 micron range. This is a common mistake that many diesel owners make, trying to save money by reducing the frequency of secondary fuel filter changes. If your fuel lift pump is weak, you may not be able to suck sufficient fuel through both filters if they are both <= 10 microns, and the primary filter is more prone to premature clogging if it is not 30 micron.

[Mistress]

Interesting. The thought did cross my mind. The housing has a rating of like 90 lph and doesn't specify what element will accomodate that. I would think the 2 micron would have lesss flow rate, more pressure drop, or both.

The boat had a spare 10 micron, so that's what's in there now. Racor lists the 2 micron as secondary, 10 micon as primary/secondary and the 30 micron as primary. Been meaning to call them and ask their suggestion for the application.

FWIW, lift pump looks new.

[skipm]

Here is the pic of the pump ,both opened & closed.
http://images.snapfish.com/343%3B636%3B23232%7Ffp4%3Enu%3D323%3A%3E292%3E2%3B 9%3EWSNRCG%3D3232995695339nu0mrj
http://images.snapfish.com/343%3B636%3B23232%7Ffp58%3Dot%3E232%3B%3D383%3D3%3 A%3A%3DXROQDF%3E23238%3A4784586ot1lsi

[Anonymous]

Looks like your stop screw settings ar very similar to mine skip.

I also see your trans cooler is mounted in same location as mine. Cummins thought it was weird as they mount them horizontal over the tranny. Does your copper stub out of the raw water pump look to have been cut from a longer section and then peened to simulate the double flare lip most of the ends have?

[skipm]

Guest you forgot to log in. Mine has no flare.

[Mistress]

But all the other ends are double flared...correct??? It would appear Shamrock modified the trans cooler location...I haven't been able to figure out why. Just curiosity.