So when I start my engine, I turn on the key, hold the glo-plug button down for about 30 sec. (for a cold start), release the glo-plug button, open the throttle slightly, and press the starter button. Usually, the engine starts right up. However, if I pause at all between opening the throttle slightly and pressing the starter button, the engine will turn over fine but won’t start. If I then wait about 15 minutes, it will usually start. Is this normal? Am I flooding the engine if I pause for 10 seconds between the throttle and the start button?
Universal M-25XP Question
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It's a diesel - you're not going to flood the engine. Why not advance the throttle before you hit the glow plug button?
Sorry but i have to say it. The name is M25XP and i have been in love with mine for 22 years.
First of all, a diesel engine does not flood in the classical sense like a gas engine with a choke.
The glow plugs are just electrical heating elements that glow red hot as long as the button is pressed. I push and hold my glow plug button continuously until the engine starts. No need to release the button before engaging the starter.
On my engine, I have the glow plug solenoid which produces much better starts. Even in below freezing temps I press the button for 10 seconds and try a start which it almost always does with one or two turns. If it does not start in 1-2 revs, I wait 5 more seconds and try again. I have never needed to go to a third try.
FWIW, my start battery is a 15 year old Group 31 AGM.
First of all, a diesel engine does not flood in the classical sense like a gas engine with a choke.
The glow plugs are just electrical heating elements that glow red hot as long as the button is pressed. I push and hold my glow plug button continuously until the engine starts. No need to release the button before engaging the starter.
On my engine, I have the glow plug solenoid which produces much better starts. Even in below freezing temps I press the button for 10 seconds and try a start which it almost always does with one or two turns. If it does not start in 1-2 revs, I wait 5 more seconds and try again. I have never needed to go to a third try.
FWIW, my start battery is a 15 year old Group 31 AGM.
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So noted and changed! If I hold the glo-plug button down at the same time as the starter button the engine cranks much more slowly. Seems to start very easily if I release the glo-plug button before engaging the starter, except if I dawdle (talk to a crew member, a fish jump, check my email).
When you hold the glow button it warms the cylinder. When you let go and dawdle it cools off before you push the start button so you are back to trying to start a cold engine.
So you don't have to do anything between letting go of the glow button and pushing the start button, thus not getting distracted and letting the cylinder cool off. There is no downside to presetting the throttle. Fuel will not flow until you crank the engine.
That is a symptom of low battery voltage and or resistance in the electrical circuit. Try cleaning all of the terminations. Maybe start with the battery to engine ground and see if that helps
It is best to forget everything you know about starting gas engines when relating to a diesel. The throttle will not "pump" fuel into the cylinders ever. You can advance the throttle a thousand time and they set it any position and the engine will have the rpm's of the final position. The throttle is connected to the governor and only controls the speed of rotation. I just bump the throttle up a bit before cranking so that it will run at about 1000 rpms when it starts.
Sorry but I have to say it -- the Universal model designation is M-25XP. I've worked on Universals since 1993 (both manufactured by Universal Motors (Oshkosh, WI) and after Westerbeke purchased the Universal brand.) I attached the Universal (M-25XP) cut sheet for your engine.
You need to check if your glow plugs are weak (old and need replacing) or not getting sufficient voltage. If you have the OEM setup the voltage should be at least 10-11 volts (they are 10-volt glow plugs.) Check the V to ground (the engine block) at each plug.
When they are energized you should be able to touch each plug, but not hold your hand there for too long. If they are ready to be replaced you may find one or more cold or lukewarm (probably shorted out or open resistance coil.) if they are original it's time to replace them -- CHEAP insurance!!
Depending on your panel (post a picture??) the GP circuit may run through your key switch, not the best setup, as the current can burn the key switch contacts. Or contacts on the preheat switch may be burned. Again you need to troubleshoot that w/ a voltmeter at the output of either/or both switches while energizing the preheat circuit.
Your battery may need help. If she is not cranking fast enough while preheating (not that that is how you should start the engine) it may need replacing. The OEM battery cables (4 awg) are notoriously undersized (should be at least 1 awg or 2 awg) and that kills the voltage to the starter. Also go through EVERY EVERY EVERY SINGLE battery cable connection, and THE NEGATIVE CABLES to make sure there is no bad cable lug crimps, corrosion, etc. Remove and clean up them ALL.
MOVE the negative battery cable from the bell housing bolt to the outside STARTER bolt for more reliable starting.
Good luck, electrics can be a bugger to troubleshoot!
PS: are you positive it is an M-25XP and not an M-25XPA engine? Their wiring and preheat circuits are vastly different.
You need to check if your glow plugs are weak (old and need replacing) or not getting sufficient voltage. If you have the OEM setup the voltage should be at least 10-11 volts (they are 10-volt glow plugs.) Check the V to ground (the engine block) at each plug.
When they are energized you should be able to touch each plug, but not hold your hand there for too long. If they are ready to be replaced you may find one or more cold or lukewarm (probably shorted out or open resistance coil.) if they are original it's time to replace them -- CHEAP insurance!!
Depending on your panel (post a picture??) the GP circuit may run through your key switch, not the best setup, as the current can burn the key switch contacts. Or contacts on the preheat switch may be burned. Again you need to troubleshoot that w/ a voltmeter at the output of either/or both switches while energizing the preheat circuit.
Your battery may need help. If she is not cranking fast enough while preheating (not that that is how you should start the engine) it may need replacing. The OEM battery cables (4 awg) are notoriously undersized (should be at least 1 awg or 2 awg) and that kills the voltage to the starter. Also go through EVERY EVERY EVERY SINGLE battery cable connection, and THE NEGATIVE CABLES to make sure there is no bad cable lug crimps, corrosion, etc. Remove and clean up them ALL.
MOVE the negative battery cable from the bell housing bolt to the outside STARTER bolt for more reliable starting.
Good luck, electrics can be a bugger to troubleshoot!
PS: are you positive it is an M-25XP and not an M-25XPA engine? Their wiring and preheat circuits are vastly different.
Makes sense; I will try this. Thanks for the help everyone!
Thanks for all this! Yes; I'm sure it's the M-25XP (not the M-25XPA) engine, as I have the original manual and it says it right on the engine.
Good advice here.
A resource for you:
Engines 101 - The BIGGEST & BEST collection of M25 Series Universal Engine Information on the Internet, plus some M35, too
Diesel Engine - c34.org
A resource for you:
Engines 101 - The BIGGEST & BEST collection of M25 Series Universal Engine Information on the Internet, plus some M35, too
Diesel Engine - c34.org
Well the engine may have been well maintained then. <big smile>.
SO MANY times oil and grease and corrosion on the exhaust manifold has made the sticker “go away.”
The IC34A wiki website and the IC30A forum site has MANY CTY and Universal manuals, including the engine technical (shop) and parts manuals.
Good afternoon. I saw that you're experienced with the Universal...Perhaps you can help me.
I have a Universal 25XP. Put the boat in the water a few weeks ago, she would turn over but couldn't start her. I assumed it was air in fuel lines however I noticed upon selecting glow plug I wasn't getting any Voltage drop. She was hovering at 13V. Oddly one day I tried again and she started, and of course the time she started I saw about a 1-2 V drop as glow plug was applied.
Fast forward to today and the problem has presented itself again.
I'm thinking the issue could be either the ignition switch itself, I removed the panel...all wiring appeared present however I didn't have my multimeter with me to test. Perhaps the ground for the glow plugs? I see where the wiring and jumpers go across the 3 plugs but I don't see where the ground is. Lastly could it be the plugs themselves?
Battery Voltage is good. The engine turns over with starter engaged. I'm just getting absolutely nothing in terms of V drop when glow plug is selected.
Thanks