Engine problem!! Help!

Michael T

Coils can be so hard to trouble shoot as they often fail to intermittent use not an outright fail.

212rowboat

yeah coils can be tricky.. .

I once had a discussion with an engineer-turned-marketer for MSD, and while they were pushing a new ignition set at a trade show.... what he shared made a lot of sense... he said those things are filled with an epoxy that resembled glass, and in effort to insulate and isolate the capacitor and all the juice store in them... all production was done by a machine, and very few were observed/inspected by human eyes, even though 'they' know it's the piece/process most likely to fail... if the 'pour' isn't perfect, there will be a fracture right where it folds over itself (the epoxy, that is) and that fracture won't manifest itself until it gets hot... and when it gets hot it will start to kick weak spark... when it cools off, and things contract it will spark properly again, just to repeat the issue over and over... only if you're lucky will it blow out to the point of no longer functioning, making t/s'ing it easy.  

all that said, it COULD be the coil in CTRC's case, but- I'm banking on cap at this point.  

NavyCTRC

MT, 212, Gener8,

I suspected the coil as well, and since they are so hard to troubleshoot and diagnose, I went ahead and put a new one on.  The problem remains.  I am waiting on the scan tool I ordered.  It should arrive today or tommorrow.  The cap remains an unknown.  Anyone out there had issues with a distributor cap on a 2005 or newer?

Michael T

I've had plenty of issues with d-caps over the years they can have microscopic faults that harbor carbon lines that cause intermittent ignition mayhem...Drew described it IMO very nicely.

NavyCTRC

MT,

Thanks!  I will still wait to get the scan tool, see if I have codes first.  If no codes, then at least I have another place to look.

NavyCTRC

Here's the latest on my port engine:

So last week we replaced the coil, spark plug wires and the crankshaft position sensor (CKPS).  We tried to start it up last week and no go, so I waited all week to get a code scanner, then Friday night while I was having trouble with the software that came with it the key was turned on for about 30 or 40 minutes.  It got dark and the biting bugs came out in force, so decided to come back Saturday.  On Saturday I got everything loaded up and it started right up, it sounded crappy for a few seconds but it eventually smoothed out and purred like a kitten.  I have had this happen before, so I was weary of it.  I shut it down after 5 minutes and checked for codes, nothing.  So I started the software again and cranked it up, thinking it wasn't going to start up again.  Long story short, it is running fine.  It started up repeatedly and I let it get all the way up to operating temp. 

Could it be that the ECM needed to learn the new CKPS?  I am thinking it didn't start last week because we didn't leave the key on long enough for the ECM to figure out there was a new part??  I haven't tested it under a load because Saturday I was busy with school work and Sunday too until the tide was dropping fast I wouldn't have been able to haul the boat out.  I have a limited window to get the boat in the water and back out as long as I am on the trailer.  I have to get the bottom re-painted and it didn't seem important if the engine wasn't running.  I am off most mornings this week, so I hope to get over there launch it in a day or two for a quick test run.

Liberty44140

I remember several years ago I replaced the IAC on a Mercruiser 5.0 and I had to do a specific start/stop/wait/start procedure for the new IAC to be learned or accepted in to the system. GREAT that its running well again! 

NavyCTRC

I had also replaced the IAC a while ago.  Since the idle was everywhere on the map last time it ran, maybe that was the problem after all.  I didn't know a new IAC would do that. 

Liberty44140

Interesting. That replacement IAC was OEM Merc part and it came with written instructions on that start/stop procedure I mentioned. I'm sure someone here will know more.

jme097

Wow. Hopefully that was your fix!

MarkB

Nice. Someone posted something similar a few years ago and there was definitely a procedure to clear the old memory and force it to relearn.

frenchship

Mark,
I am pretty sure it was 212 rowboat that mentioned that procedure.

NRath

NavyCTRC said:

New aftermarket starter....could any of the connections on the starter be causing this problem?  Starboard engine has new starter as well, it doesn't have any issues.

Thoroughly cleaned the flame arrestor as it was gunked up

Engine occasionally (random times) will run at "surge" idle (800-1400rpm) for a minute or two, then it dies and won't restart.

I've recently been chasing the circuits on my V-P.  The power for most everything actually comes from the starter post.  Those extra 2 wires on the positive post feed the ECU and ignition.  It doesn't really sound like you're problem, but it's worth checking.  I have no idea how it's wired on dual motor boats, but I figured it's worth mentioning.

Edit: OOOPPS! looks like I missed the last page & that you"ve got it going.  Good to hear!  Makes me leery of those dual motor monsters!

NavyCTRC

 that is really good info NRath, seeing how I just replaced the starters on BOTH motors, I wonder if that is where my problems originated???  Well, it starts up consistently, but it hasn't been ran with a load yet.  Keeping fingers crossed!

rasbury

@212rowboat lost me there at the end...pulling the wires off the swapped cap, if the swapped cap is good, what problem are you chasing? I assume what your saying if it still does not run, then your looking for a bad wire? If the wire is bad, it's grounding out somewhere and it's fireworks under the cap? AND, if that is so, does that ruin the cap? @NavyCTRC on the plus side, you have a lot on new parts you won't be chasing a future problem with! My worry about my boat, 2005, alittle over 200 hours, EVERYTHING is going to go bad at once! I don't touch anything I don't have too, although doing a starter once and raw water like 3x, no pokin around to cause trouble unless I need to!

NavyCTRC

Ras,

I think that has been part of my problem, some of these parts should just be automatically changed out at a certain age.  Our boats are 11 years old, some things should have been replaced every 5 years, regardless.  I think it's running now.  Haven't tested it in the water yet.

NavyCTRC

Was over at the boat last nite, tried to test it in the water.  My problem is not completely fixed.  There is some sort of electrical short, somewhere, but I don't know how to find it.  The engine was running and I wanted to bend over and look behind it, so I briefly put my hand on top of the fuse box that sits on top of the motor, as soon as my hand touched the box the engine stumbled and died.  I turned the key off and back on, only a single beep from the self test, tapped the fuse box and it beeped twice and was able to restart.  Checked all the connections on fuse box, all looks good, checked fuses and relays inside fuse box, swapped out relays with the spare one by one, the problem persists.  Something is grounding out and making the engine stall, after much wiggling and fiddling, it will restart but anytime throttle is applied it will stall again.  Does anyone know where I should start looking?

212rowboat

consider taking pics with your phone, then disassembling the wiring from the box and breaker- and clean everything with brush, if needed, contact cleaner, and then reassemble.  a shot of silicone spray on those connections will ward off future corrosion- and is something I do when I store the boat... the entire engine room gets is... when you put it back together use the pic for ref if you need. 

it sounds like you have a bad connection.  or a faulty breaker.  most likely you just need to clean and tighten everything up.  other than the juice that runs through to the starter straight off the batt, your vitals are wired through that breaker.  

212rowboat

ras- 

if you have an ignition wire that is grounding to something such as an exhaust manifold, it stands a chance of spraying your spark indiscriminately inside your cap... I would not have believed this either, but it was proven beyond doubt to me... my engine actually ran better with the entire offending plug wire removed than it did with it on- I had only the one dead cylinder with it off, but with it on?  no go... 

we know that juice looks for ground... we know it'll take the path of least resistance.. but I didn't realize that once a ground is established that it will 'hold' that or at least try to hold it even when it is no longer the shortest path or one of least resistance- or at least where ignitions are concerned... who knew, right?  I sure didn't... but as I said, this was proven to me beyond the shadow of doubt... just one bad wire that was punching through the sheathing and grounding on a manifold it was touching... 

NavyCTRC

212,

Thanks for the reply, cleaned up some connections today, found one pin in one connector that had some greenish corrosion inside it.  Two pins on another one looked a little darker than the rest, cleaned everything up, put it back together, started up and ran good, previous symptoms not there anymore but it was too late to launch as the tide was dropping fast.  Will attempt another in the water test tomorrow.  This has been a saga!  BTW: Brand new plug wires all around, so I wouldn't expect a crack in one, but I will check anyway.

aero3113

That's great news! Hope that was your issue.

NavyCTRC

FINALLY FIXED!! A thousand thank you's to all that posted! 

randy56

Navy, happy happy for you, load and go boatin ! I've have been following this sence begaining. Hope you do not have anymore trouble the rest of the season.

rasbury

Good news indeed! I bought my boat up around your area, looks like some nice boating around those parts...