Just repowered my Catalina 36 Universal mp25xp with a rebuilt. Starts right up but when I take my finger off the ignition it just dies.

Jops

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Sep 19, 2020
14
Catalina Catalina 36 San Diego
Just repowered my 1989 Catalina 36 Universal mp25xp with a rebuilt. Starts right up but when I take my finger off the ignition it just dies. I double-checked the glow plugs. It seems to work after I bleed the lines each time. After I bleed the lines it starts right up. Has no problem starting up for the day after the initial cold start. I think that air is getting into the line. I tightened all the pipe clamps along the line but that didn't work. I will change out the fuel lines tomorrow and hopefully, that is the issue. Can anyone think of any other issue that might be causing this?
 
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Feb 8, 2014
1,300
Columbia 36 Muskegon
Can't be anything to do with the ignition, that's just a coincidence. Air leak can be in any fitting between the tank and lift pump. Anything under suction. These can be a b***h to find, air will leak in under suction where fuel can't leak out under pressure. Check that the filterers are properly seated. Does yours have the bleed knob that routes the bled air and fuel back to the tank? You can leave that partially open and the engine won't die.
 

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
Air can also enter the return line at the tank if the return line does not extend to the bottom of the tank. Check valves to prevent fuel leakdown at the primary filter and/or the mechanical fuel pump often fail and overnight leakdown occurs.
 
Feb 26, 2004
22,760
Catalina 34 224 Maple Bay, BC, Canada
I wrote a Mainsheet tech note last year about the check valve in the "standard" Racor fuel housing. IIRC, I also posted here about it, search under: Fuel Starvation.

 
Jan 19, 2010
1,169
Catalina 34 Casco Bay
Fuel pump is tied to the starter button. Glow plugs disengage upon release of the starter button, so not in play. Other possibility could be if you set up doesn't use a T handle stop ( that simply stops the fuel flow) then it uses a solenoid ( electric) that is tied to the fuel system incorrectly
 
Jan 5, 2017
2,263
Beneteau First 38 Lyall Harbour Saturna Island
Fuel pump is tied to the starter button. Glow plugs disengage upon release of the starter button, so not in play. Other possibility could be if you set up doesn't use a T handle stop ( that simply stops the fuel flow) then it uses a solenoid ( electric) that is tied to the fuel system incorrectly
Had a similar problem that turned out to be the solenoid return spring. PITA to find but now I know what to look for.
 

Jops

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Sep 19, 2020
14
Catalina Catalina 36 San Diego
Thanks for all the information. I did read the article on the check valve. I also have lots of barbed connectors in the line where air could enter. As who knows how old the fuel line is, I ended up replacing all the fuel line (about 23 ft when all said an done). I also reseated the water separator filter. That seem to do the trick. It started right up. I need to go back down and double check that did fix it with another cold start. Thanks for all the info. I will let you know...
 
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Oct 22, 2014
20,993
CAL 35 Cruiser #21 moored EVERETT WA
Sounds good. AIR in your Fuel line is alien and not good for your engine.
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Air or lift pump. keep the glow plugs on as you start the engine - if it dies when you release the plugs your wire wrong. I believe the way your wired the lift pump only turns on when the glow plugs are on OR you have oil pressure. If your a paid member of Catalina 36/375 they have wiring diagrams on line (CatalinaDirect.com or toad have some also).
Les Troyer
CIA 36/375 pre Mk2 tech Editor
CIA 36/375 Commodore
 

Jops

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Sep 19, 2020
14
Catalina Catalina 36 San Diego
The wiring was not changed when the new engine was installed. Couldn't get it started this weekend. Bleed the system. Lots of fuel, engine turns over but doesn't start. Frustrating. Had it start before but always had problems with cold starts.
 

senang

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Oct 21, 2009
304
hunter 38 Monaco
If you have an automatic fire suppression system check the pressure in the extinguisher. If pressure is to low the stop solenoid is activated. You should have an override for this situation.
 

Jops

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Sep 19, 2020
14
Catalina Catalina 36 San Diego
I am replacing my fuel lift pump from the little cube type to the cylinder type. Having an electrician come and double check the wiring. All fuel lines have been replaced. Turns over but doesn't want to start unless I give it a shot of WD-40
 
Jan 5, 2017
2,263
Beneteau First 38 Lyall Harbour Saturna Island
I am replacing my fuel lift pump from the little cube type to the cylinder type. Having an electrician come and double check the wiring. All fuel lines have been replaced. Turns over but doesn't want to start unless I give it a shot of WD-40
Sounds like air in the lines if nothing else has changed.
 
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Jan 19, 2010
1,169
Catalina 34 Casco Bay
WD 40 in place of ether indicates a glow plug issue. Air in the lines is air in the lines and WD and ether won't overcome this.
 
Jan 19, 2010
1,169
Catalina 34 Casco Bay
I use a temporary piece of clear vinyl tubing from the hardware store in line (with hose barbs as required).. The tubing lets you see if there is air.
Ok if it is temporary that means when exchanged for rated fuel line , air has a way into the system. How do you compensate for this ?
 
May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
Fix the air leak, if there is one. Double check the lift pump is running, both when glow plugs on and when engine is spinning. Catalina changed the wiring quite a bit over the years on how/when the lift pump is on. It won’t hurt to power it separately and bleed the line first using the knurled knob for ~3minutes after the primary filter fills up, then loosen the bleed screw on the top of the secondary filter till you get a good stream of clear fuel (towels handy to catch the flow). Don’t touch the injectors. Leave the raw water inlet off till it starts up - or you will fill up the muffler and flood your new engine.
 
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Jops

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Sep 19, 2020
14
Catalina Catalina 36 San Diego
Slowly fixing issues and learning a lot. Thanks for all the imparted knowledge. One issue that was brought up that repowering the engine and replacing the fuel lines is all in good but if I don't clean the tank what was the point. I had the tank cleaned and the fuel polished. Here is what we discovered. After5.jpg This might have been causing air bubbles as some of this sludge goes through the fuel tank valve it could cause enough pressure that it sucks air at a connection. 30 years of sludge removed. I am also eliminating the electrical issues. Replaced the electrical harness and rewiring everything. Lots of loose connections and corrosion. Learning a lot as well, however, I have 3 wires that don't make sense how they were connected before and how the wiring diagram from Catalina Direct shows. So some advice would be great. What are these three wires and what am I looking for at my instrument panel? I don't think my panel has a low oil light, high temp light and whatever is between them in the red circle. I also had a bunch of wires coming off my alternator going to the i screw on the tach and the L on other gauges, didn't make sense.
 

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May 20, 2016
3,014
Catalina 36 MK1 94 Everett, WA
The excite wire to alternator is your switched power. It turns on things with the key. The op wire comes from the oil pressure switch. The AC or tach wire goes from alternator to tach