Mercrusier Ignition Problem

[FB Coach]

The motor is an 06, RWC, Carb, 4.3 with the Alpha one. The boat was bought new in October and only has 21 hours on it. The last two trips out, four times the motor just turned off and then started back up within seconds. It happens so fast that I don't even have time to think, just enough to see the tach drop and then comeback up. Its a very quick stumble or hesitation. Its not fuel as it happens very quick. It seems to be something in the ignition. The dealer says they can't find it unless it happens more frequently or fails all together. I'm not very happy at waiting for this to fail when I'm out on the ocean. I do have Vessael Assist but would prefer to not use them. I getting to the point where it don't want to take my new boat out.

Has anybody had this problem and what was the fix?

I'm thinking about replaceing all of the ignition components to eliminate the problem,

Any suggestions?

I love the boat, but its not comfortable taking something out that I believe is going to fail.

 

[Haut Medoc]

Re: Mercrusier Ignition Problem

Welcome to iboats......
Is it still under warranty?
If you took it in for a problem, make sure you get it documented, & what was done to remedy the situation....
In this case, zip!
Anyway, in the meantime, you shoud have a look at all of the ignition connections .....
Ie coil, ign. switch, the harness plug, alternater, starter, oil pressure switch.......
My guess is a loose/faulty connection......
Bring your DVM with you so if it happens, you can at least test it.....
It does sxck when you can't trust your boat off-shore.....
Try to recreate it when out with a buddy boater following you on a relatively nice day, not too far out.......

 

[DHPMARINE]

Re: Mercrusier Ignition Problem

UMM if you bought it new in October,Don't you have a warranty ? We might have ideas,but let Mercruiser have at it first.Then we learn a bit more.

DHP

 

[Bondo]

Re: Mercrusier Ignition Problem

Is there Any Pattern to it,..??..??...

Only when it's run at What rpms, for How Long, at What Temps, Etc......

 

[FB Coach]

Re: Mercrusier Ignition Problem

No pattern what-so-ever. Once coming off idle. Twice at 3500-4000 rpm, once trolling speed 1500rpm? When it happens its not even the same. Last trip out it did it three times right in a row, bam,bam,bam. The next time it did it just one very qick time. The blink of and eye thing, and one time it happened twice in a row with about a thee or four second delay.

 

[tommays]

Re: Mercrusier Ignition Problem

So this is blip that does NOT require a restart of the motor ?

kinda of like a mis-adjusted shift switch

Tommays

 

[FB Coach]

Re: Mercrusier Ignition Problem

Thats the first thing I'm going to look at. Yes, I never need to restart. Its a total lose of spark for just a second or two. I'm going to start with following the purple ignition wire, and looking for loose connections and if that's not it the shift interupt switch is next. From there I don't know where to go.

 

[Bondo]

Re: Mercrusier Ignition Problem

Ayuh,.........

Time for the Old Shake, Wiggle,+ Tug at it Test............

And, Ya Know,.....
The Dealers don't like doing that,"Keep throwing Parts at it" thing,......
Unless of course,.... It's on Your Nickle................

Good Luck............

 

[sailsmanship]

Re: Mercrusier Ignition Problem

I totally agree it sounds like an electrical problem, but you might not want to rule out a fuel problem. I had the same problem a while back, and since it happened so fast and recovered so fast, I went through everything to try to find a loose or bad connection. It wasn't until a friend of mine insisted in checking the sock at the end of the fuel pickup in the tank that I found the problem. It didn't act like fuel starvation. Mine was sediment, but with yours being so new, if it was something, it would have to be something foreign. Just a grab at a straw.......

 

[Don S]

Re: Mercrusier Ignition Problem

The Thunderbolt ignition has been used for years and is very reliable. But connections do get bent, corroded, and loose. Pull all the connections and look at them and check for bent pins and corroded parts. Trust me, corrosion on an 06 engine near saltwater is not unheard of.
One thing I will suggest you check and to be careful how you check it, is the shift interrupt switch. Merc has been using the plunger type switches and it seems lately they have been the cause of all kinds of wierd problems. But Merc knows of no problems what-so-ever
Anyway, once you get out in the clear and do not have to go to neutral for anything, disconnect the shift interrupt switch. Then go for a run and see what happens. If the engine runs fine all the time plug it back in and try some more.

NOTE: With the shift interrupt switch disconnected it will be very hard to get the drive out of forward or reverse and into neutral. You could also damgage something trying to get it out of gear. If you MUST get it to neutral with the shift interrupt switch disconnected, SHUT THE ENGINE OFF. move the lever to neutral, then restart.

If you take someone with you for these tests and let them run the boat at idle while you hook and unhook the shift interrupt switch and use some common sense, then everything should be fine. Just be careful.

 

[uaw9fan]

Re: Mercrusier Ignition Problem

Just a couple suggestions. First take a look at the gang plug at the back of the motor. Make sure it is pushed on all the way. It should be maybe a 1/4 inch from the steel bracket. It is located just aft and left of the distributor while looking at the motor from thr front. Second, check to make sure the ground wires at the back of the motor are tight. Mercruiser moved the ground stud to the upper bell housing bolts recently. I've seen where the factory put the ground cable from the battery to the old spot and never tightened the nut on the upper stud with the ignition module ground. It caused the same type problem you describe.
What brand of boat is it ?

 

[FB Coach]

Re: Mercrusier Ignition Problem

Last night I looked at some of the wiring. I found a bus bar located on the stren of the boat that was for the grounds and two of them were very loose. I also could wiggle the purple wire at the ignition switch a little so I tightened up these items. I don't think any of them were really lose enough to lose contact. The cut off switch looks suspicious. I have the plunger type and from the point where the plunger gets pushed in to allow for the gears to engage, and the open throttle position it dosen't seem to change. In other words the plunger is pretty much in the same spot whether it is killing the motor for shifting or 3/4 throtlle. I expected to see the switch return to the idle neutral postiion or fully extended. I have never seen one of these switches before so I am only speculating. i need to get it out on the water and experiment[colour=null][/colour]

 

[Bondo]

Re: Mercrusier Ignition Problem

i need to get it out on the water and experiment

If everything is working Right,.......

That Switch will Never Move,...... Unless there's a Load on the Prop,ei. In the Water...........

 

[FB Coach]

Re: Mercrusier Ignition Problem

Well I spent a couple of hours doing the tug and wiggle test in the drive way. Nothing showed up. Wednesday I'm taking it out and will try the shift cut off switch. After that its time to put lots of pressure on the dealer to find it. Just when the fishing is starting to get going. I'm sure they will take weeks to find the problem if they can.

 

[Coors]

Re: Mercrusier Ignition Problem

bad connection

 

[bigbrownbuku]

Re: Mercrusier Ignition Problem

had a similar problem cross my path. 1 of the main breaker terminals was installed by a sumo and broke almost completely then was painted with neoprene. only the neoprene was keeping it contacted...most of the time. pull and tug not just complete looms but all the terminals, there arent many.