2004 225 HO #6 Intermitten Firing????

[Rude520]

2004 225 HO FHLSRM

Quick rundown. Boat was running about 4 mph slower than normal. And wasn't producing normal bow lift. On a Ranger so not alot of lift anyway but it's not what it was. Pulled plugs and #6 doesn't look like its fired a lick. Compression is great in all 6. This was back last winter. I can fire all 6 spark plugs with the software. All sound and look the same. No codes stored.

Here's what I've done so far.

Brand new 1100cca battery
Fuel injectors cleaned and tested. All good.
New ignition coils and spark plug wires. Have resistance tested coils and wires. All good. Has brand new plugs. Still 5 look like the normal dfi plug. #6 is clean.
Rpms would seem normal. Running around 5800 wide open. Changed hub kit and prop as well. Engine seems to be running good. Has an in gear idle miss. Its slight but there. Doesn't do it out of gear and idling.

Championman has helped me greatly over the past several months. But I know it's extremely hard to troubleshoot an issue hundreds of miles away. I pulled the plugs tonight to check and low and behold still a clean #6. Ohm testing from plug to emm shows continuity so I assume no wiring issue.

Let you in also on an intermittent problem that may or may not be related. Sometimes after starting the check gauges system may not immediately go through its checks. May be 30 seconds down the lake and it will do its thing. Next time may be fine. This past weekend it did its thing like it should. No delays on foing through the checks.

I have not had a chance to check the 40v system yet. I've got the manual and have been looking at doing that next.

I'll take any help/advice anyone can offer.

Thanks

[JoePA]

Move the plug to see if it follows or just replace the plug? Also, When the engine is running make sure #6 cylinder is sucking air in and not blowing air out. Could be a reed or reed gasket issue.

[Rude520]

Move the plug to see if it follows or just replace the plug? Also, When the engine is running make sure #6 cylinder is sucking air in and not blowing air out. Could be a reed or reed gasket issue.

It's the third plug in that hole. By that I mean I've changed that plug 3 times.

I've not checked the air sucking/blowing. I will check that tho!!!

Thanks Joe

[mactlman]

plug is wet and clean like dead hole? or clean and dry like no fuel?

[Rude520]

Its damp and super clean!!!! I called a local tech and his first thought without looking at it is a leaky head gasket or base gasket. Said its steam cleaning the plug. Seen it before. Got one on the way. I'll give it a whirl!!

I should say I may have been premature in saying its firing intermittently.

[Bassmeister]

Check that 40v system....somehow I think it will lead to the pdp.....that is in my mind the ONLY weak link to the DFI engines.....I've replaced one on my 03 225 HO and on my 03 250.....

[Bassmeister]

Chris, is it getting out of the hole ok?? Another thing that I ran into was struggling to get out of the hole. Pulled the cover and let my son get it on plane......it struggled but got on plane but you could tell it didn't have full power. I noticed the bottom right throttle body wasn't opening up. Found a broken throttle body shaft. The bottom two throttle shafts are connected by a rubber hose....you could try to pull the cover at home and see if one of t bottom butterflies will open while holding the top ones closed.Just a thought....

[Rude520]

Chris, is it getting out of the hole ok?? Another thing that I ran into was struggling to get out of the hole. Pulled the cover and let my son get it on plane......it struggled but got on plane but you could tell it didn't have full power. I noticed the bottom right throttle body wasn't opening up. Found a broken throttle body shaft. The bottom two throttle shafts are connected by a rubber hose....you could try to pull the cover at home and see if one of t bottom butterflies will open while holding the top ones closed.Just a thought....

Yessir comes out of hole good. Runs out pretty well. It has lost about 4 mph. And just doesn't bow lift like it used to. And has that in gear miss at idle. It's not noticable that I can tell missing wfo. But you can tell it's down a shade of power. Prop new and set up is the same.

On a side note I have had the rubber hose on 5 vibrate shut due to rubber getting hard and vibrating shut. Lol. Show stopper.

I've witnessed the engine basically be down a cylinder. And it's nowhere near that. Which to me , and I'm jaded cause I want it fixed lol, that possible water intrusion is causing slight improper combustion so it's not up to its potential. Well something is causing it. Lol.

I trouble shoot communication and scada equipment for a living so I'm all about the tough ones in troubleshooting. This one tho is wanting to give me a run for my money. About to a point of coming to Florida with a keg and Fred, you, and myself will get drunk and fix it or use it to start the bon fire!!!!

[Bassmeister]

I'M IN !! Hang in there bro....I fit tha good fight on mine this spring after a thermos cover broke and flooded the engine....pdp replacement did it for me..... total different circumstances here I know. Have done a compression test?

[Rude520]

I just checked it again last night. 115 in every cylinder except 6. It was around 112.

I'll get it figured out. I appreciate all of your alls help!!!

Is the pdp swappable? Buddy has the same engine. I'll go grab his and swap it and see if it fixes it.

[mactlman]

I just checked it again last night. 115 in every cylinder except 6. It was around 112.

I'll get it figured out. I appreciate all of your alls help!!!

Is the pdp swappable? Buddy has the same engine. I'll go grab his and swap it and see if it fixes it.

all good reading- not a compression issue

[Danrude]

You can swap the PDP's. I think your local tech is right sounds as if it may be a head gasket leaking.

I just checked it again last night. 115 in every cylinder except 6. It was around 112.

I'll get it figured out. I appreciate all of your alls help!!!

Is the pdp swappable? Buddy has the same engine. I'll go grab his and swap it and see if it fixes it.

[Bassmeister]

You can swap the PDP's. I think your local tech is right sounds as if it may be a head gasket leaking.

What Dan said...I put the pdp off my 225HO on the 250....they're the same....

[Rude520]

I changed the head gasket this evening. Gonna start it on the muffs in the morning and make sure all is good. Old head gasket isn't terrible but its worse shape then I thought it would be. Power head was replaced in 2012 and it has just a little over 100 hours on it. Again nothing stood out but I'm still hopeful this is the fix. Will update in the morning.

[Rude520]

On the muffs she started right up and sounded good. No leaks that I could see. Put it in gear and no miss. Then I realized there wasn't any load just spinning out of the water. Lol. We fish a tournament tomorrow so I'll get a full check then.

[Bassmeister]

Just remember.....after a couple heat cycles....retorque the head....

[Rude520]

The head gasket did not do the trick. Some have ask about the plugs. Hopefully they load up.

My next course of action is to put the boat on muffs and do a cylinder drop test with the software. Its gonna screw up and show me the problem eventually. Lol.

[ChampioNman]

Chris, try this. Take the air box off and check the throttle plates, make sure they are fully closed with the motor off. Next manually move the throttle linkage on top of the throttle bodies while putting slight pressure on each of the bottom two butterflies, the coupling from the upper to the lower may have come loose and not allowing the plate to fully open. Once you check that start the motor on muffs and use either your hand or a piece of paper and hold it over each throttle body and see if the paper gets sucked in or you can feel vacuum with your hand.

[Rude520]

Got off work early. Here are my dynamic test findings:

Fred the throttle bodies all open together and the bottom 2 are good. I changed those hoses a couple of years ago due to that very problem

On the software with the engine running I disabled all the injectors. This made a difference with each one. So all 6 responded to being disabled. Did the same thing with spark. Pulled boots one at a time and again the engine changed. (Did it with insulated pliers and my 29Kv gloves.)

Now using the palm of my hand I felt all 6 throttle bodies. # 5 is puffing air out. Not pulling or feeling a vaccum. (Clean plug is not in this hole). So looks like I have some work to do here.

Other observations. Was pretty amazed at how little a difference there was disabling an injector at idle. It makes sense a little I guess but I was expecting more of noticable difference.

Still no grand explanation of my clean plug (unless the power head base gasket is leaking) but I may have found the miss and lower rpm issue with the number 5 blowing air back out the throttle body.

[Bassmeister]

Ok, you got to remember that #5 cylinder and #5 throttle body are on different sides.....IE: # 5 cylinder looking from the back of the engine is the bottom right......from the front of the engine the #5 throttle body is the bottom right.... The emm will correct idle to around 650 rpms.....even if you have a dead hole.....