Hard to start engine

Richard Bain · January 10, 2007, 10:46:24 AM

I have read a few threads, but this one has me stumped. My engine 1986 M25 starts every time when cold. After it is hot, this is what happens. I hold the glow plug in for 20 seconds....I can hear the "ignition key on" sound. Then I push the start button, and nothing happens....dead....just the "ignition key on sound" continues only very faint.

any clues ??

Thanks much

Richie

Ted Pounds · January 10, 2007, 12:21:33 PM

Check all the connections first. That sounds typical of a bad or corroded connection (hard to start when warm). Good luck. Also, if it's hot you probably shouldn't have to use the glow-plugs.

Ron Hill · January 10, 2007, 03:03:34 PM

Richie : Not to sure what an "ignition key ON" sound sounds like?, but as Ted said the usual problem if the engine will not start when it's WARM -- is a bad/loose connection.
BTW, if the engine temperature registers above 100F, I never use the glow plugs and always get an immediate start.

Stu Jackson · January 10, 2007, 05:02:40 PM

While you're at it "down there" in the engine room, check the fuse holder and fuse from the ignition button to the starter solenoid.

Mike and Joanne Stimmler · January 11, 2007, 08:09:47 AM

Is the fuse holder at the starter solenoid or behind the engine control panel? Also, I've never had the control panel off, is it easy to do?

Mike

Stu Jackson · January 11, 2007, 08:22:45 AM

The fuse holder is cleverly hidden somewhere behind the alternator, between it and the starter.

The control panel is easy to get off, harder to replace because... Depending on how the boat was built, the silver part of the panel with the gages in it may well have been installed with machine screws, which means when you unscrew the screws, the nuts at the back will fall off. Rather than get into a long involved explanation (search on "panel" -- an example is: http://c34.org/bbs/index.php?topic=3171.0), I recommend that you get a flashlight and a mirror, or get into the aft storaage compartment, and look at the back of the panel to see how yours was built.

Ron Hill · January 11, 2007, 03:48:38 PM

Mike : On your "89" it's easyest to locate that fuse and it's holder thru the door from the head. Behind the alternator and infront of the starter and starter soloniod. If you take out the steps and the removable panel over the engine - you'll get more light to see.
I wrote this up in the Mainsheet tech notes many years ago - here's what you're looking for. When you find that fuse holder open it up and check the following for corrosion. The 30amp fuse ends (continuity), and MOST important the contacts of EACH end in the holder. I finally found corrosion on one of the holders contacts after many many hours with a multi meter - on a friends boat!!!

Your engine control panel can be removed after taking off the plastic outer cover. I believe that the panel is held in with 6 Phillips head screws. You'll have to jockey it around thew fuel cutoff. I've taken the time to solder all connection - it took a couple of hours. Good Luck

sedelange · January 12, 2007, 08:31:51 PM

You never said how you get the engine started when warm. Do you have to wait until it cools? Is it every time or occasionally? When it fails to turn over, is there a significant voltage drop? If you you do not have a connection problem, you could have a starter that has a winding that open when hot.

Steve DeLange