Fuel pump questions

[hwd]

Subsequent to my last post regarding changing my fuel filters, I'm now unable to get the engine to fire at all.    When I open the bleed nut on the secondary filter I'm not detecting any fuel flow...When I turn the key to the pre-heat position, I hear a single "click" from the pump and nothing else.  When I crank the engine, I also get no flow from the bleed nut.  In the past, when I activate the ignition switch, I have been getting either no or intermittent noise from my "low oil" buzzer, could this be a problem with the oil switch,which I believe is also connected to the pump?  Or is it possible that my fuel pump itself is no longer working?  Should I be able to detect fuel flow by gravity alone at the secondary filter even if the pump is not working?   Any help here would be appreciated.....thanks.

[Jim Hardesty]

Sounds like a fuel blockage.  Could the fuel shut-off valve be closed?   
If there is half a tank of fuel the engine will start and run with out the pump.  If there is fuel in the lines to siphon.  Do the problem logicaly.  Start at the primary filter check fuel flow then just follow the fuel lines checking that fuel is flowing after each station.  You may want to jumper the oil pressure switch to keep the fuel pump running.  If the engine was running OK before the filter change think that you just need to bleed the fuel system.
Hope this helps,
Jim

[KWKloeber]

Subsequent to my last post regarding changing my fuel filters, I'm now unable to get the engine to fire at all.    When I open the bleed nut on the secondary filter I'm not detecting any fuel flow...When I turn the key to the pre-heat position, I hear a single "click" from the pump and nothing else.  When I crank the engine, I also get no flow from the bleed nut.  In the past, when I activate the ignition switch, I have been getting either no or intermittent noise from my "low oil" buzzer, could this be a problem with the oil switch,which I believe is also connected to the pump?  Or is it possible that my fuel pump itself is no longer working?  Should I be able to detect fuel flow by gravity alone at the secondary filter even if the pump is not working?   Any help here would be appreciated.....thanks.

Just to clarify - which engine?

[KWKloeber]

Just to clarify - which engine?

ooops, okay - 35B.  my faux pas.

Are you getting fuel to the injector pump?  start at one end or the other and work systematically.  You can try to pump fuel into a can to see if the oil switch is closing/powering the lift pump.  Or bypass the switch with a jumper wire and terminals to plug into the harness.

Ken

[Ron Hill]

hwd : On your M35BC engine your problem could be the oil pressure switch or the fuel pump or both!!

When you first turn ON the key switch you should get an audio alarm telling you there is no oil pressure. If you hear that alarm - Here's what I'd try:
Close the raw water thru hull.  Crank the engine with the fuel cutoff pulled all the way out.  In about 20  seconds you should hear the alarm stop.  That tells you the oil pressure switch is OK.

If you don't get an alarm when the key is turned ON it could be the switch or the sounder.  From what you said it could be the connections to the sounder (behind the engine panel) or the oil pressure switch.

Take the two leads off the oil pressure switch and put them together and then use the glow plugs.  While that is happening feel the fuel pump and also have the bleed nut loose.  I'm guessing that you might be able to feel the fuel pump pulsating and/or see the fuel squirt out of bleed nut.  If that happens, it's the oil pressure switch that's bad.

Remember you NEVER want to engage the glow plugs for more than about 20 seconds at a time or you'll burn them up.  Just turn the key/ glow plugs to ON for a few seconds to see if the fuel pump is pumping!!

If I were to throw parts at the problem, I'd suspect the oil pressure switch rather than the fuel pump.

I'd also call Westerbeke @ 508-823-7677 (and talk with Joe Joyce X234 or Russ Hagen X233) and go over your problem with the experts.  

You can also give my ideas ideas a try and see what happens.

Keep us posted.


 

[Stu Jackson]

Here's the Critical Upgrades link that may apply to you:

http://c34.org/bbs/index.php/topic,5078.msg41829.html#msg41829

Please read the links and the discussion about the wiring to the oil presure switch and the glow plugs.

Check if the fuel pump is still working.  How full is your fuel tank?

You have a "self-bleeding" engine.

[travlinon]

I had exactly the same problem with starting after changing both fuel filters on mine. After trying various starting procedures I finally found that the fuel pump was u/s which can be found as you describe by listening to the pump ticking when you turn the key to the glow plug position. Although the fuel tank in our boats are higher than the engine (which means once motor has been operating it doesn't matter if the fuel pump is not working) I found that there was not enough pressure to get the fuel to start flowing past the injector pump. Once the new fuel pump was installed and operating the motor started and I have not had a problem since. I do not believe my fuel pump had been operating for the twelve months prior to this as I had never heard the pump and thought this was normal.

Ken

[hwd]

Thanks, everyone for your excellent ideas and information...I really appreciate your help as I'm not a mechanic and am feeling my way forward here....

[travlinon]

This is a link I found that helped me track down the importance of the fuel lift pump on initial starting after changing filters.
catalina350.com/phpBB3/viewtopic.php?f=11&t=657&start=0
Hope it helps
Ken

[hwd]

Thanks, Ken....that link was very helpful

[Stu Jackson]

That link was fun to read.  They'd obviously read THIS forum!  

Very important:  one skipper wrote: "The reason I began to question whether my fuel lift pump was working is that after changing filters, I opened the bleed vent on the secondary filter and put the switch in the glow position over a minute..."

NOT a good idea.  Burning out glow plugs is one of the unforeseen consequences of the "new wiring" through the glow plugs and the oil pressure sender when bleeding.

This was discussed in great detail via the Critical Upgrade link and the links within that post.  While they claimed to have read our forum about this issue, they had two pages of discussion about it which essentially reinvented the wheel.

That skipper finally found out his pre-heat (i.e., glow plug) solenoid was faulty which in turn stopped his fuel pump, which was OK, from working.  He replaced the solenoid and the fuel pump worked just fine.  Good detective work on his part.  Also saved his glow plugs from dying.  Maine Sail has written about burning up his glow plugs when he switched from FLA to lithium batteries because the voltage was so high he used his "standard" 12 seconds and burned them out!

Please, please, please, read the Critical Upgrades and avoid damage by re-wiring your fuel pump around the glow plug key switch for bleeding your engine.

Good luck.

[Robert Mann]

What I have done during the bleeding of my system is to take a jumper off the circuit breaker that is to the right of the fuel pump.  I can't remember if this one is hot all the time or if it is switched by the key switch.  A wire with 2 alligator clips is good enough to run the pump on a temporary basis to vent the system and to prove if the pump is good.  A temporary feed eliminates all the messing around with 2 people and the glowplug operation etc.  If you think about the wisdom of the wiring it isn't all that clever.  If the oil pressure fails there is sufficient fuel in system to allow the engine to run on and create damage.  Also, if the system siphons fuel enough for the engine to run under power, albeit at a reduced level, as mine certainly does, the safety system isn't much of one.

[Stu Jackson]

What I have done during the bleeding of my system is to take a jumper off the circuit breaker that is to the right of the fuel pump.  I can't remember if this one is hot all the time or if it is switched by the key switch.  A wire with 2 alligator clips is good enough to run the pump on a temporary basis to vent the system and to prove if the pump is good.  A temporary feed eliminates all the messing around with 2 people and the glowplug operation etc.  If you think about the wisdom of the wiring it isn't all that clever.  If the oil pressure fails there is sufficient fuel in system to allow the engine to run on and create damage.  Also, if the system siphons fuel enough for the engine to run under power, albeit at a reduced level, as mine certainly does, the safety system isn't much of one.

Good work.

In the long discussions about this, previously linked, there was some talk about the oil pressure switch being part of a "safety design." 

You are absolutely right that this doesn't happen in our boats.   We have so noted in those prior discussions.

However, what we must take into account is that the fuel pumps are called "lift" pumps for a good reason:  many boats have fuel tanks below the engine, hence the name "lift."

While I don't recall any Catalinas made with fuel tanks in the keel, the newer engine wiring for the M35s applies wherever Universal sold their engines.

So, if the "lift" pump was disengaged by this "feature," the engine could get starved for fuel.

Just not [always] on our boats...

[Ron Hill]

Guys : As Stu and I have pointed out for years, the C34 fuel tank is higher than the engine and fuel will syphon to the injection pump so the engine keeps on running.

In 1994 I wired the lift pump to the blower switch (purposely) and ran the engine like that for over a year - up and down the entire east coast water way!!  
I used the lift pump as a fuel flow meter! If I turned on the blower (+ lift pump) and the engine RPM increased slightly I knew it was time for a fuel filter change!!

When I installed the new engine I took off the double contact oil pressure switch and installed a single contact oil pressure switch for a M25XP engine.  You then take the fuel pressure power wire off the spring loaded ON pole of the key switch (which also has the glow plug wire) and attach the fuel wire to the ON pole.  Then the fuel pump will run with the key to ON, the oil pressure switch will sound until there is oil pressure.  The glow plugs still engage in the spring loaded position.
This by passes the "safety feature" that doesn't work on a C34 anyway!!

When you change filters and want to check your self bleeding system it's much easier.  Turn ON the key switch and you'll hear the NO oil pressure alarm - and the fuel pump pumps.  Open the bleed nut and see the fuel squirt out.  Then just turn OFF the battery switch to stop the oil alarm sounding rather than climbing up from the engine (the steps are OUT) to turn OFF the key!!
 
Much simpler and you still have all the systems functioning and the appropriate alarms.

A few thoughts

[John Langford]

I just did a primary filter change and noticed that the fuel pump did not start ticking and draw fuel into the injector lines until I had used the hand pump on the filter to fill the bowl and eliminate the bubbles at the bleed screw on the top. Once I did that I ran the fuel pump and the glow plugs for about 10 seconds and the engine fired immediately and ran without a hiccup from that point forward.

The 200 series pumps are a bit finicky so you can reduce the hand pumping by filling the new filter element and bowl with clean fuel before reinstalling. BUT, reconnecting the filter and bowl to the filter body is a bit messier if you do that so put down some oil blankets.

I also used the drain at the bottom of the filter unit to reduce the mess of removing the old filter but getting the drain to reseal can also be a pain. If I was absolutely sure I had the room I would replace the filter with a 500 series unit which is a lot simpler and easier to work with.