1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

[roozter2550]

Ran 30 miles out and the motor ran fine.
We anchored on a fishing spot for about 30 mins and then decided to move to a diff location.

I cranked her up and she was idling normal for a few mins while we pulled up anchor then suddenly died.

I tried to crank her back up and it was like she was locked up.
Took the cowling off and noticed the starter drive gear was still engaged but nothing else out of the ordinary.
Tried cranking again and still locked up.
Checked all power connections and still nothing.

At this point, I took the starter rope out from under the cowl, wrapped it on the flywheel, and tried to turn the motor over to see if it was siezed.

It was difficult to turn but it wasn't locked solid. Also, the starter gear dropped back down out of engagement.
Tried the key again and she cranked normally, and fired up but def not running normally.

The exhaust sounded different, and slight vibration.
We decided to head for port and not risk getting stuck 30+miles out.

Way down on power. Took some creativity just to get on plane but she made it the whole way in.


Got her home, and ran on the muffs.
Sounds likes it's not hitting on all cyls.

Changed out the plugs and did a compression test.
103-105psi on all six holes.
Fired her back up, (still sounding like crap and running rough), and used an inductive timing light to check the coil packs for output...all 6 firing.

It's at this point that I'm at a loss.
Motor has 450hrs and has run great up until now other than a dead hi-press fuel pump 2 yrs back.

Any help is appreciated.

 

[bighood]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Did you get your engine going? I have a 1997 225 EFI Mariner sounds a lot like the same symptoms. Some times idles okay but rough-ish and won't go up on plane, but if it gets up on plane runs fairly good, but much more rpms than normal for speed. Any help would be great.

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

I swapped out the plugs for a set of new Champion QL77C

Used a borescope to look at the cylinder walls, no damage and crosshatch pattern is still visible


I haven't done anything else due to work and other issues at home but I did order new plug wires yesterday for it and should have those next week.

I am going to try to troubleshoot a little more this weekend...

the plugs on cyls 5 + 6 come out soaking wet and I think they're not firing.
I'm going to swap the ign coil from cyls 5 and 3 and see if the misfire "moves around" and smooths out

even though I did verify spark output by using a timing light on each plug wire but those 2 plugs coming out wet have me thinking either weak coils, wires, or a ground issue and those cyls are not lighting off

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Haven't touched the boat for almost a month...
...work has been crazy


today's report...

check all grounds and coil connections

used a spark tester, (the one that looks like a spark plug with no ground strap)
hard to tell in the bright sunlight but looks like all coils are firing although I think some are weaker

found 1 plug wire boot showing signs of age/cracking from all the messing around with them, (ordered a new set should be here this week)

removed the coils and tried to test them with a digital volt meter, (got the service manual), but I don't think I'm doing it right. when I shold have continuity, I don't and when I shouldn't, I do
first one I tested I thought I hit the jackpot picking the right one but then they all tested the same

reinstalled the coils in their original locations except for swapping #3 and #5

the bottom 2 spark plugs, #5 and #6, are soaking wet with fuel, hence the swapping of the coils to see if the miss smooths out. I was thinking that maybe 5+6 are dead and moving the coil from 5 to 3 would spread the miss and smooth out a little
no change

with the engine running, I used a pair of insulated clamps to remove and reinstall plug wires 1 at a time
no change in the sound of the engine until I pulled #5. sputtered, died and I had to restart
pulled #6 and same thing happened...sputtered, died and had to restart


this thing is killing me!

plugs 5+6 are wet
plugs 1,2,3+4 look good
I'm thinking 5+6 not firing but when I remove the wires, engine dies


weather looks like it's starting to turn so I packed it in for today
going to try to remove the injector plenum tomorrow and get a peak in there, (harness, connections)

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

also, there's a crap-load of thick sludge coming out at the prop

 

[Faztbullet]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Sounds like the injectors are stuck open on 5 and 6 or the have something in the reeds holding them open...

 

[bighood]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Sounds like the injectors are stuck open on 5 and 6 or the have something in the reeds holding them open...

I have my 225 Mariner at the shop. Got updated and only running on 2 cyl out of the 6. Mechanic has tried everything easy. Fuel pump has 45 psi fuel pressure. 95 to 100 all cyl's. He thinks the reeds may be messed up. He said he has to take the EFI stuff off to get to it.

 

[bighood]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Sounds like the injectors are stuck open on 5 and 6 or the have something in the reeds holding them open...

I have my 225 Mariner at the shop. Got updated and only running on 2 cyl out of the 6. Mechanic has tried everything easy. Fuel pump has 45 psi fuel pressure. 95 to 100 all cyl's. He thinks the reeds may be messed up. He said he has to take the EFI stuff off to get to it.

Please keep posting anything you find....and ultimately the culprit causing the problems. I will post whatever ends up fixing mine. Maybe the same thing causing the issues. Your initial probem sounds like what mine was doing.

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

if the reeds are stuck open, then compression would be down

the air/fuel charge would get pumped back thru the reeds instead of into the transfer ports up to the cylinder


I'm going to pull the injectors and send them out for service

 

[Faztbullet]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

if the reeds are stuck open, then compression would be down

Not necessarily , if you was missing a pedal or a tip of one compression would still be fine but cylinder would flood as charge would not be sucked in due to crankcase equalization....

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

I'll be pulling the injectors this week to send them out for service...

...hopefully, I'll be able to see the reeds without to much further disassembly...?

 

[roozter2550]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

update

it turned out to be a broken reed petal on #4 cyl and reversion back thru it was being taken in by cyls 5&6 causing the whole mess

many thanx to Chris Carson Marine who not only helped me out with the diagnosis, but has great pricing on new reeds

she's running like a champ again

 

[Faztbullet]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

Not necessarily , if you was missing a pedal or a tip of one compression would still be fine but cylinder would flood as charge would not be sucked in due to crankcase equalization....

See I told ya!!!!

 

[bighood]

Re: 1998 Mariner 225HP 3.0 EFI running rough and sounds like crap

See I told ya!!!!

That is great. Glad to hear someone got there boat going. My mechanic found bad reeds (2 missing) and replaced them with carbon fiber reeds. $400! Got to the lake and within 3 or 4 minutes the engine made a real bad noise and shut down. I pulled the throttle from about 3/4 to zero as soon as I heard the noise so not sure if the engine seized or not but she died. Then wouldn't start, when I bumped the started it was as if it was locked up. After about an hour the engine would crank over but I didn't do anymore than that. Took back and found that #6 cyl piston was all kinds of messed up. The mechanic said the crank was bad and it was actually a good thing the cyl went first. I ended up having to purchase a new crank, all new pistons, and had the block bored. It is supposed to be done this next Wednesday 10-10-12. estimated cost is to be a little over $3000! ouch-but that is the cost of playing

Here is my question(sorry so long):
While looking for a used crank I found one that was out of a newly rebuilt engine that the seller stated the mechanic had installed the reeds incorrectly. That is just what I had replaced before my engine laid down. Is this seriously a possibility? I am investing $3000 more and really don't want her to fail again and find it is due to the reeds that were just replaced. Any advise would be most appreciated. -Jr