Engine Starting

Tali · August 15, 2017, 05:11:54 AM

My Universal M35BC engine always starts immediately on first push of the button. This weekend we had some issues:

Saturday - the boat had been idle for two weeks. Engine would not start. Looked at engine nothing looked out of ordinary. It took four attempts to start it. Ran fine turned it off at fuel dock. Started perfectly and ran for four hours without incident.

Sunday morning - obviously cold engine from overnight again would not start but now the audible alarm went on. Again looked at engine nothing seemed out of normal. After four tries with the alarm wailing it turned on and alarm went off. Ran fine for three hours. Turned it off. Checked the engine front and back. Turned it back on without a problem.

No fuel, oil, or antifreeze leaks anywhere - all levels are good.

What could the culprit be? Fuel pump?

Enrique

Ron Hill · August 15, 2017, 08:47:15 AM

Tali : The engine would not start? did the starter turn over? vigorously?
You engaged the glow plugs each time?

Tali · August 15, 2017, 09:02:19 AM

Starter cranking was normal. All fluid levels fine. Engine cutoff was fine. No indication of leaks anywhere of oil, fuel, water or antifreeze. Fuel in rancor cup looks fine. After started ran fine. Started right up and operated normally on warm engine start. Seems to happen on cold starts.

Noah · August 15, 2017, 09:26:10 AM

Glow plugs or glow plug circuit?

Tali · August 15, 2017, 10:58:25 AM

I always allow count to ten on cold engine. Ill look at that next time on board by looking at voltage drop while heating the plugs but wouldn't they either work or not? Remember after four tries or so the engine starts and runs normally and no warm engine starting problems.

Stu Jackson · August 15, 2017, 11:52:17 AM

Good idea to check the voltage while holding the glow plugs.

Try glow plugs for longer.

Ron Hill · August 15, 2017, 01:35:25 PM

Tali : Here is your starting sequence for the M35BC engine:
When you turn ON the key switch you should hear the "no oil pressure alarm".
When you turn ON the glow plugs (spring loaded) you should see about a 2 V drop on the volt meter (draw from glow plugs) and the electric fuel pump turns ON.
As the engine cranks / starts and the oil pressure comes up turning the "oil alarm" shuts OFF. The glow plugs are already OFF and with oil pressure the electric fuel pump stays ON.

I'd check your glow plug wiring and both contacts on the oil pressure sender. Might also check that your fuel pump is pumping.
I wouldn't engage your glow plugs for more than 15 seconds (check your engine manual!!)

A few thoughts

Jim Hardesty · August 15, 2017, 02:38:28 PM

Careful not to crank the engine too much. It's possible to fill the water lift muffler and get water in the cylinders. The cranking time is in the manual, I don't recall what it is but it's not very long.
By chance have you changed the fuel filters lately? You could have a small leak and be getting air into the fuel system.

Jim

KWKloeber · August 16, 2017, 09:34:14 PM

Enrique

The B engines need a working oil switch to power the fuel pump. They also need a working preheat solenoid to power the pump while cranking (no oil pressure yet while cranking.)

I would start w/ checking that solenoid (voltmeter on a glow plug terminal.)

I had a customer with EXACTLY your situation -- it was both the fuel pump AND the solenoid. I BELIEVE, the pump was bad first, and he preheated for so long trying to start her, that it then fried the solenoid.

BE CAREFUL -- the OEM solenoid IS NOT continuous duty, so if you preheat for more than needed you WILL BURN OUT the solenoid. Replace it with a continuous duty solenoid (from NAPA.) Listen for fuel pump with preheat button in -- that's what activates the fuel pump before there's oil pressure.

ken

Ed Shankle · August 17, 2017, 08:15:42 AM

Hey Ken,
Help me with my left brain-right brain disfunction; I don't understand your continuous duty definition

If prior to this you asked me how I would interpret "continuous duty", I'd say the solenoid stays active as long as you have the key turned over, whose risk is burning out the solenoid.
Thanks!
Ed

Stu Jackson · August 17, 2017, 09:58:42 AM

Ed, the answer is in the text from the Critical Upgrades, here: http://c34.org/bbs/index.php/topic,5078.msg41829.html#msg41829

KWKloeber · August 17, 2017, 10:57:48 AM

Ed

Liken it to the Admiral's "continuous duty" honey-do list.

Short bursts are okay, but if you don't take a break you'll burn out. Same for the solenoid switch - it's the pull- in coil that can't take constant energerizing, it heats up and burns out.

We're talking preheat solenoid switch here, not starter solenoid switch

A continuous duty solenoid switch is made like the energizer bunny..

Ron Hill · August 17, 2017, 01:55:37 PM

Guys : Also the M35BC engine has a different glow plug vrs the M25/XP series engines.

A thought

Ed Shankle · August 17, 2017, 02:27:06 PM

Ken - I was hoping for a more parochial explanation of why is it called continuous duty? Assume there is a technical reason for it.
Stu - I read the link, but as I noted above, no explanation, just says to use a continuous solenoid. Which I did 2 years ago, but I never bothered find out it means.

Regards,
Ed

Ron Hill · August 17, 2017, 02:55:05 PM

Ed : What part of -- burning up if continuously left ON don't you understand??

Stu : In Critical updates -That does NOT apply to any M25XP engines (mounted in Catalina 34s) as no XPs came with a glow plug solenoid!! However, the M35, M25XPB and M35BC engines are the ones with the glow plug time limitation.

A few thoughts