86 Mariner 3297 Electrical/Engine Issue

I

imspacemancraig

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Joined
May 24, 2009
RO Number
31301
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543
OK, this may be better posted on the engine forum, but thought I would start here first as this is happening on my Carver... The engines are Crusaders 270's.

So, I have posted many times last year about my starboard engine problems and its issue with stuttering after about 45 minutes underway. With a different mechanic last season, we went through all sorts of different things to try and resolve this (and a lot of money). List: new distributor, cap, plugs, wires, new electronic ignition kit, coil, resistor, then fuel pump, fule filter, fuel lines, rebuilt carb. We thought we got it at the end of the season only to have the problem come back up again this year.

So, got myself a new mechanic, ran through what we have done to date. He believes that the problem is not fuel and definitely electrical somewhere in the ignition system. He found a wire that he said was connected wrong and changed that and he also replaced the fuse on the engine (right next to distributor). Didn't fix things on the last ride.

He still believes that something is heating up and then causing a breakdown of the spark to the ignition system. It is only happening on one engine, the other runs great. When the issues rears its head, my current work around is shut it off for about 15 minutes, run on one engine, then fire it back up and she runs fine again, only to do it again later.

So, my question to you all, how/where does the power run up to the helm? He was thinking the ignition switch, but has decided that we should take it out this weekend with him on board, go make the problem happen and then start doing voltage checks and heat checks to see what we can find. So, with my basic knowledge of how this all works, there has to be a source of power that runs up to the helm where the ignition switch and everything else connects to. Does it all connect to the same source or does each ignition switch up there have a separate source?

Something that has also been in the back of my mind, not sure it is related, but could be. I have a GPS unit mounted up top that consistently turns off when we are under way, like it loses power or heats up. My VHF also throws a low voltage warning every so often. I am almost thinking that something going up there could be contributing to this. Although I would expect both engines to act up, but not sure.

The mechanic is almost 100% sure it isn't fuel related and mechanically the engines are very sound. So that just leaves the spark in the equation. Any thoughts?

cmariner, hoping you see this, maybe you have some insight...
 
I agree it is probably electrical. Clean and tighten all connections including battery cables, ground buss under dash and any multi pin connectors.
 
Also make sure that the distributors are advancing properly. I've seen weight springs break/go weak and cause running issues.
 
Sounds like the alternator may not be putting out enough to keep that battery charged. If the engine runs just on the battery when the battery gets weak the gremlins come out. This could also cause the other electrical issues.
 
pdecat - good suggestion, will go through them, probably should pick up some sort of wire brush or something before I head up. It seems like when the issue occurs, it feels like losing gas, but I think its losing spark actually.

RamSport47 - we went through that all too. The advanced is all good. We even swapped with the other engine to see if the problem would move and it didn't. We replaced one of the distributors, the weights an springs as well as the innards were all rusted up.

dancerscap - that was one of my thoughts too, but the volt meter say ~14 the whole time the engine is running even when the issue starts. The new mechanic said all the readouts on it are OK so thinking somewhere else down the line...

Heck, wondering if the battery switch in the cabin could be an issue. Doesn't seem to matter which battery bank its on though, the problem still happens.
 
check engine ground cable connection too
 
Dumb question, but where would I find the engine ground connection? It is in an obvious place or even in the engine compartment?
 
Ground connection is from block to battery negative post, lots of possibilities, trace backwards from battery. If guage says good check wire feeding ignition. Maybe it's breaking down when it gets hot.

Could still be fuel, too. If fuel pump gets hot it could be an old fashioned vapor lock.
 
Craig, heres something you might try if its possible. Since both engines run on basicly the same electrical type system, I believe, nad if Im wrong someone speak up, That maybe you could switch wiring harness plugs between them. There is one main plug just above the trans shift lever that runs that engines electrial. If you were to switch them and the problem follows, then you know its in the electral system. If it stays on the same engine, then it's within that engines electrical system. Not sure if the leads are long enough to cross over but if not then it wouldnt be hard to get a couple sets of that type plug and build a patch cable.

Just a thought!
 
The fact that you are getting a low battery reading on your electronics, that suggests to me that the problem may indeed be electrical. Other than a bad ignition switch or a bad wire or ground, I don't have any other suggestions. I thought I was the only one that had the really off-the-wall problems that mechanics or other technicians said this was the first time they had ever seen this.
 
Well I have to ask what size wires both positive and negative run to the helm? I assume your boat only has an upper helm? Also what is the distance from the main panel to the upper helm?
If you have a lower helm does the same problem happen there?
What I found on my boat was the following there were 2 positive power feeds and a single ground.
1) a #6 that feed the ignition, running lights, horn and half the assy rocker switches.
2) a #8 that feed the VHF radios and plotters and the other 1/2 of the assy switches.
3) a single #6 for the ground on both of the above power feeds.
I like you had the electronics low voltage problems but I had no engine issues.
I ended up replacing the feeds with the following, (2) #1/0 leads for the positive power distribution and and 2 #1/0's for the ground busses I installed a 2nd ground buss.
I replaced the feeds with high current 4 position battery switches so I could select power from almost any battery bank in the boat. I may end up putting a single or pair of 31 series batteries in a cabinet pedestal that the hinged dash/helm sits on.
I no longer have any power issues, in addition the windlass switch on the dash is now only a low voltage current up/center hold/down switch. The windlass and bow thruster get their primary power from (3) 31 series AGM's under the front berth.
Here is what I found, the connections were in terrible shape under the dash and required replacing numerous splices the previous RO had installed for GPS, LORAN and other electronics. The OEM blowers actually got their power from the upper helm switch that switch now controls a relay and the ER blowers get their voltage from which ever engine is selected or house battery bank selected. It appears over the years previous owners had added equipment and when they removed it all they took was the equipment and left the spliced wires in a ball under the dash. The fuse blocks were also glass fuses and they were both corroded, I removed and replaced the fuse blocks with ATC marine grade BlueSea fuse panels.
Good luck sometimes it's as simple as a loose or dirty power connection more then likely it's the mess other owner's left behind and no maintenance was ever performed on the wiring, switches and distribution fuses.
Bill
 
Hey cmariner... no you aren't the only one. I really have a pain in the rear one hear and have so far stumped 2 mechanics.

So, we took it out again the past weekend with the mechanic on board armed with voltage meters and other things. Problem happened and we made it continue to happen (instead of powering down) while he checked readings on the engine. He did not see any drop in voltage or spike on anything. He wants to "think about" it some more so in a holding pattern right now. But, I think he is now considering it could be fuel related. So waiting for a call this week.

We went through most of the electrical connections looking for potential issues and could not find anything. I think the one electronics device that is having an issue is due to a bad connection for it as everything else works fine. The GPS is the only thing losing a connection now and I just need to climb under everything to see its connections. The VHF was some bad wires which I fixed, easier to get to.

d r Young, I like that idea and will suggest to the mechanic, but after this weekend, I am not sold on electric problems. The ignition wasn't warm, coil was fine and all voltage readings were good. We have done a considerable amount of parts swapping between engines and unable to "move" the issue.

My gut still says this is fuel related personally. The vapor lock or maybe some sediment in the tanks/lines somewhere still seems like a possibility to me but I am really a fish out of water when it gets this deep into the engine mechanics of things.

cmariner - did you have a fuel water separator on yours? All mine has is a fuel filter on top of the engine somewhat near the distributor. I heard from another shop that they had redone a lot of older boats fuel tank pickups. They said the original rods going down in the tanks have a small screen on them to filter large sediment before traveling up the rod, through the check valve, then onto the tank to engine switches. They said what they have done is to pull those up, remove the screens on the end, put them back in and then add a fuel/water separator after the check valve before going to the tank switches. Thereby adding an easier to get to filter and able to see if there is anything inside of the tank. Would an extra filter cause any flow restriction problems by doing this?
 
Craig
My Crusaders had remote fuel filters located port of the distributors-sounds very similar to your description. They are a compbination fuel/water separator-screw on type. I used NAPA replacement filters on mine. Fuel tank issues could be a real possiblity as my new 89 Santego had a fuel pick up with a rubber hose and a mickey mouse screen on the bottom that was pretty well plugged. I replaced the tanks on my Mariner so I can't honestly say what the pick up situation is on that model. If you are using ethanol, I would definately look at the the tank pickups and change the filters.
 
Sounds like the exact filter I have and funny enough I get the replacements from NAPA as well. It has a metal tin on the outside and then a filter on the inside that you can replace one or both parts. My mechanic recommended that I put seafoam in there and run it again this weekend and see what happens. He is trying to be very methodical about this doing one thing at a time to narrow this down. I get the impression that he may be thinking fuel related too. I have already had new filters put on, new fuel lines from filter to pump and pump to carb put on, new fuel pump and the carb cleaned and rebuilt. So the only parts left are the lines going back from the filter to the tank feed switch and then from switch to the tanks. I replaced the check valves last season as well, so only part there is the tube going down into the tanks.

So, how expensive and painful was it to replace the tanks on the mariner? Going from memory, that doesn't look like an easy job. I would guess at a minimum the deck needs to be pulled off...
 
Oh, and currently all the places on the water by us sell non-ethanol gas, which we pay a lot extra for...
 
The port tank will require you to pull the engine. I had to have the yard replace that tank. The starboard tank I replaced myself. As I recall, I pulled the exhaust manifolds and replaced them at the time too and got some extra room. I was able to R&R the starboard tank with just me and my son at the dock. Your results may vary.
 
While I am not sure if this is the cause of my headaches yet, anyone know of a way or company that can pump out and clean a tank without removing it? Some way to vacuum things out etc.?

I am not convinced this is the issue yet, but with everything we have done to this engine and parts we have replaced, this is one of the last pieces to the puzzle that hasn't been looked at. This or the fuel lines leading from the tank to the switch over and then on to the filter.
 
Any company that offers diesel fuel polishing should be able to pump out and clean the tank. When I had the leak issues, I used 2 different companies for 2 different issues. They pull the fuel sender and go down with a wand to suck out the fuel. When the first leak leaked gas into the bilge, that company also sucked all the gas out of the bilge-that was a scary time for me.
 
Any chance that you engine control module is having problems when it gets warm?

I'm not familiar with Crusaders, but if they are like Mercruiser or Volvo multi-port injection engines the engine control module is easy to remove. Removing a couple of bolts and disconnecting a couple of connectors is all that is required. You might want to consider swapping the control modules from one engine to the other.

Mike
 
quote:
Originally posted by imspacemancraig
remove the screens on the end, put them back in and then add a fuel/water separator after the check valve before going to the tank

Click to expand...


Having lived through a problem similar there is a lot to be said in doing this. Next time you are out with the mechanic have him pull the anti siphon value and see if it is plugged. In my case if I got it pulled right away you could see the crud before it had a chance to get flushed clean

Good luck
Niles
 
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