Fuel pump question ...

[Robs Hubris]

Hello:

I'm working on a the same "starts but then stalls after a bit" problem that several others have posted about. (A4 installed on a 1981 Catalina 30).

I think I've got a pretty good handle on what to diagnose and potentially replace (Carb, fuel line, filter, fuel pump, ignition system, coil, etc.). Thank you for all the prior input!

Question though ... I see two replacement electric fuel pumps offered, one is 2-3 psi, the other 3-4.

I''m tempted to default to the higher PSI ... but you know what they say about assumptions. Any advice?

many thanks,

Rob Anderson
Hubris
Catalina 30 on Lake St. Clair, Michigan

[Dave Neptune]

Rob, the higher pressure pump is for the Cat 30 and others like my old boat an E-35. The more aggressive pump is due to the additional length of draw as the tanks are just further away. Also for the same reason there are 2 mechanical pumps as well.

Dave Neptune

[Robs Hubris]

Dave: Thanks much for sharing ... love the knowledge here. And, I'm glad I asked!
best,
Rob

[roadnsky]

I'm working on a the same "starts but then stalls after a bit" problem that several others have posted about.
...I think I've got a pretty good handle on what to diagnose and potentially replace (Carb, fuel line, filter, fuel pump, ignition system, coil, etc.)

Hey Rob-
Can you give us a little synopsis of what's going on with your issues?
Changing out the fuel system, ignition and coil may solve it BUT you won't know what the problem actually was.

Sort of like solving a mouse problem by razing the entire house and re-building it.

Systematically doing one thing at a time will be sure you nail down the issue AND give you a better A4 "education"...

[Robs Hubris]

Hi Jerry, sure thing ... appreciate the thought process.

A prior poster, from 2015 I think, posted the exact description.

Engine starts normally, ease choke down ... runs, water exhaust good.

After a minute or so, there's a slight increase in rpm and it stops.

Starts again fine ... runs, little uptick, dies.

Starts ..then each subsequent start, the stall interval decreases.

Just on a hunch (having absent mindedly left the ignition on for some time) I replaced the coil yesterday and the problem repeated exactly as described above.

I ordered a fuel pump from Moyer, with the thought that if it's not needed, I'll have it for back up as the current pump looks downright ancient.

thoughts?

thx,
rob

[ndutton]

Please repeat the same test with the fuel fill cap removed taking care that no deck water enters (a Catalina 30-specific risk).

[Robs Hubris]

Please repeat the same test with the fuel fill cap removed taking care that no deck water enters (a Catalina 30-specific risk).

Did that yesterday, no effect on problem.

I did fill, nearly fill, the gas tank recently. But the engine ran fine for a couple of outings before the current problem appeared.

[edwardc]

...Engine starts normally, ease choke down ... runs, water exhaust good.

After a minute or so, there's a slight increase in rpm and it stops.

Starts again fine ... runs, little uptick, dies.

Starts ..then each subsequent start, the stall interval decreases.
...

This also sounds a lot like the "stuck ball" problem I have experienced several times with the Facet pump, described in more detail here.

The diagnostic and temp fix are very easy.

[JOHN COOKSON]

Try bypassing or shorting across the OPSS. The OPSS can fail in all sort of weird manners. Been there, done it. It kept me guessing for awhile.

TRUE GRIT

[Robs Hubris]

Try bypassing or shorting across the OPSS. The OPSS can fail in all sort of weird manners. Been there, done it. It kept me guessing for awhile.

TRUE GRIT

Thanks John ... is there a write up anywhere on how to do this?

[tac]

Checking/Bypassing the Oil Pressure Safety Switch

You can check the switch at least two ways:

1. If you have a voltmeter or multimeter (VOM scale set to DC voltage), connect it across the switch. That is, put the red (+) test lead on the switch terminal screw from the coil, the black lead (-) on the other screw to the fuel pump. With the ignition ON and no oil pressure (engine not running), the switch contacts should be open and you should see 12 volts (nominal) on the meter. With oil pressure up (engine running) the switch should be closed and the meter will read near zero. If it reads other than a few tenths of a volt, the switch contacts are damaged - get a new switch. If you see the meter reading bounce around as time passes with the engine running, the switch is bad - get a new one.

2. If you have no meter, or are hesitant to use one, here are two ways to jump, or short across, the switch:

a) If you have a short wire with alligator clips on both ends, connect one end to one of the switch’s terminals, and the other end to the other terminal. This “jumps” across the switch contacts, bypassing them. Oddly enough, this temporary wire is called a “jumper”. This method is temporary.

b) If you have no alligator clips, then just connect both of the existing wires going to the switch together. You can do that by putting both wires together under either one of the switch terminals. Or, you can disconnect both wires from the switch, connect the ring terminals on their ends together with a short #8 (or so) machine screw, washer, and nut. Wrap in electrical tape. This method, while still temporary, is preferable if you’ll be waiting for a new pressure switch.

[JOHN COOKSON]

I carry a metal piece in my onboard tool box that is the same width and thickness and is bit longer than 2X the tang on the OPSS. If the OPSS ever fails while I'm under way I can pull the wires off the OPSS tangs and push then on the bypassing tab, wrap them with a piece of tape, and I'll be good to go.
In fact I cary two of them because I know I will probably drop\loose the first one.

TRUE GRIT

[Robs Hubris]

OK, I have two more diagnostic steps to try tomorrow.

Any advice on getting to the fuel pump, it looks tight and tricky ....

[JOHN COOKSON]

OK,
Any advice on getting to the fuel pump, it looks tight and tricky ....

It's probably to late for a diet so think skinny. Wear a long sleeve shirt so you don't tear your arms up. Good lighting and a mirror will also help. You will know you are in the thick of it when you get so dizzy you can't figure out which way is clockwise\counter clockwise to loosen or tighten. Having the correct tools is a big help.
Have fun.

TRUE GRIT

[tac]

Fuel Pump Relocation

An option might be to leave the old electric pump where it is, and mount the new pump in a more accessible location. Never having seen the inside of any Catalina, I can modestly say I’m quite unbiased.

If you do that, or ANYTHING to the fuel system, read and follow the Coast Guard requirements of The Boatbuilder’s Handbook, found here, http://www.moyermarineforum.com/foru...ead.php?t=9280. These requirements are not just Nice to Do, they are law.

In that book, Subpart J, Fuel Systems, Title 33 CFR Section 183.566 Fuel Pumps: Placement, requires that, “Each fuel pump must be on the engine it serves or within 12 inches of the engine, unless it is a fuel pump used to transfer fuel between tanks.” This 12” requirement is for the pump. Thus, the pump, if mounted within 12” of the engine, may have any length of hose from the pump to the carburetor.

Steps to do this might be:
a. Cut the fuel line from the fuel filter to the pump suction end at the pump. Remove that hose from the discharge end of the filter. Throw it away, don’t be tempted to reuse it.
b. Cut the fuel line from the old electric pump discharge to the carburetor, and remove it from the carburetor. Throw it away.
c. Mount the new pump within 12” of the engine in an accessible location.
d. Run new USCG compliant Type 1 ethanol rated fuel hose from the filter discharge port to the new pump suction inlet. Follow all the USCG rules on routing, support, fittings, clamps, etc.
e. While you’re at it, if you don’t have a “polishing” filter and fuel pressure gauge, add them now. Using the search function of this forum will provide lots of examples. Connect them after the new pump’s discharge - filter first, then gauge. Again, follow the CG rules for mounting and support, using new A1 hose.
f. Connect the fuel pressure gauge to the carburetor using A1 ethanol rated hose.
g. Finally, connect the new pump up electrically.