Help, where do I start?

[KonaKing]

try this and see if its what youre looking for

https://www.planetnautique.com/Corre...MEFIManual.pdf

[sebenfitty]

Yes there is but you will need a MEFI 4 scan tool like something from DIACOM but they are pricey. Best bet find a shop close that scan it for you but even that is going to cost an hour of labor.

Check out Rinda.com there may be some cheaper ones out now but i havent checked in a while


What about crank sensor ? No crank sensor no spark

I had one go bad on my 2004 PCM ZR6

I’ve got fire at the coil wire and plug wires. Still acting like it has no fire though. I thought about crank sensor also.

[IDBoating]

I can't think of many reasons a broken belt would cause rough idle problems. No belt = no cooling water and no alternator. Engine likely shut down due to overheat, long before the battery would have run down. But unless you REALLY overheated the engine, I wouldn't think any serious damage would have occurred before the engine protected itself.

Then you pulled it out of storage, and it ran fine for 30 minutes? And only had problems after you changed the oil? Those are some strange symptoms.

Are you certain the oil pan is sealed? Have you reconfirmed the proper oil level? These engines try to protect themselves when they think they don't have sufficient oil. Maybe all the oil you think is in there really isn't?

Any chance you knocked loose a connector while changing the oil? If everything was running OK before you changed the oil, and then you had weird engine problems AND electrical problems (on the display),etc., that really sounds like you may have just bumped something accidentally.

Pretty amazing coincidence if things ran fine before the oil change, and then suddenly you had all these multiple symptoms immediately afterward. I'd look for a single, simple solution like a bumped connector.

EDIT: Please also check the engine kill switch at the helm. We've had a few of those go intermittent on this forum, and nobody thinks of it at first (including me). It will kill the spark and it's possible to waste all sorts of time chasing down "bugs" when the kill switch is (accidentally) doing exactly what it's supposed to do!

[sebenfitty]

@ID
Yeah, definitely checked the kill switch multiple times. Just ruled out the crank sensor also. I’ve been all over the engine bay looking for anything I may have knocked off. The first time I started after the oil change, the tach alarm also started alarming and quit working along with the rough idle. Thought maybe they had something to do with each other.

[sebenfitty]

try this and see if its what youre looking for

https://www.planetnautique.com/Corre...MEFIManual.pdf

This is perfect. Thanks.
I found a scan tool kit. But it says OBD II connection. Sure looks like the 10-pin on my harness though.

https://store.custombuiltmotors.com/...ntrollers.html

[lee]

This what most techs use.

https://www.rinda.com/marine/diacommarine.htm

[sebenfitty]

Dropped it off at a shop to have them check it out. Just got the call. Anybody selling an engine?

[BrentP]

Froze??


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[sebenfitty]

Shop called and said no compression. Didn’t even think to check before I took it to them. Didnt think to ask if they checked all cylinders. I was a little flustered. Thought for sure this was gonna be a computer issue.
Hopefully get it pulled and back together quickly.

Just gotta figure out the easiest/cheapest way to get this done. I was about to drop a lot of $ on new interior.

[IDBoating]

I'm still baffled by how we went from this:

ran it for 30 minutes or so to warm the oil up, then changed the oil. Seemed to be running fine.

...to "no compression" and "need a new engine".

Before dropping the coin on a whole new engine, I think I'd drop by the shop with my own compression meter and confirm no compression in all eight cylinders. Something just doesn't make sense here.

[sebenfitty]

Definitely going to confirm the compression loss myself before i start stripping it. I’m pretty baffled as well.

If it has to be rebuilt I’ll be doing it myself.

[chpthril]

No compression on ALL cylinders, is like impossible, short of the crank breaking at the last main, and none of the pistons are moving.

[LourdesNaples]

I think you will find help faster if you use google. When I need help with my homework, I don't write on some forums, I just use free precalculus homework help from professional writers, who will make your study easier.

[sebenfitty]

Got the shop’s write up. #3 is 0 compression. #6 is low. Best case scenario is head gasket failure due to the overheating. Heads after that. Fingers crossed for the gasket(s). Hopefully start pulling her down today.
Be able to see if any further issues when the heads come off.

[boatwakes]

Its most likely stuck exhaust valves from failed riser gaskets. Both those cylinders are directly below the center rise exhaust and susceptible to the following:

Overheat compromised the gaskets, next time you ran water through it, gaskets allowed some water into the exhaust ports, motor sits, water does its magic and bam, stuck exhaust valves cause major headache. YOU WILL NOT NEED A NEW ENGINE, just plan on a valve job for both heads and new exhaust manifolds and risers (use nothing but OEM manifolds and risers or you will have immediate problems once recommissioned). We do these all the time and somewhere on here I did a write up on it. If you can't find it, I'll do another for everyone including gasket part numbers, tools, lubricants and sealants. Super easy job, just takes time and some specific tools most particularly a torque wrench capable of doing angles (Snap on is the best but that's another $1000). Fel pro makes the intake gasket kit and marine head gaskets and you'll need new head bolts, cheap insurance.