Engine struggled after de-winterizing

[Michigan boarder]

Can't you use the bolt in the center of the crank pulley?  You can kind of see it in this picture.

[oldjeep]

4 minutes ago, jbower said:

dont forget to pull the plugs. It may make it a little easier

Pull the plugs to do a leakdown test

3 minutes ago, Michigan boarder said:

Can't you use the bolt in the center of the crank pulley?  You can kind of see it in this picture.

You can if you remove the raw water pump - which is what those 3 bolts are holding on when you have a non mercruiser engine

Edited March 3, 2016 by oldjeep

[jfw432]

53 minutes ago, jbower said:

dont forget to pull the plugs. It may make it a little easier

Sounds silly but I guess I've never had to bother with this so I it only vaguely crossed my mind. I always just pulled the one plug I was working on and then put it back in... Avoids the potential of mixing up plug wires.

I've also always worked on engines where the crank bolt was a 7/8" or 1" socket so it really didn't matter how much torque you apply to that thing....only that your wrench was big enough.

[jbower]

Just saying pull the plugs to make it easier to turn over 

[jfw432]

On 3/2/2016 at 6:38 PM, electricjohn said:

You test it with a ohm meter.  At room temperature you should measure 3500 ohms across the 2 pins.  At engine temp (160*) you should measure 500 ohms.  If the temp is really cold, like freezing, reading will be as high as 7500 ohms.  Do not unplug sensor while engine is running.  The sensor has a yellow and black wire plugged into it on the front of the intake manifold.

Ok results so far...

Leakdown test shows only 10-15% leak per cylinder.

Still can't read any codes for some reason. LED on terminal E and F and jumper between A and B. Turn the key to "on" and the LED just stays on. 

Resistance on the coolant sensor was showing 2300 ohms and it was about 55°F outside so that sounds a little off. I didn't want to wait until the engine warmed up to test again because of what happened next......

 

So I pulled the valve covers because it's usually easier to see what's going on during a leakdown test. I had to move the coil on the back of the drivers side as well as push a wire loom out of the way on the passenger side. All of my gauges quit working except perfect pass which continues to work normally including the rpm readings. Engine runs fine at the dock. The lights on the gauges work but all of the dials are stuck. Any idea what I screwed up? It's dark now and I didn't bother pulling the cover off the electronics behind the engine to see if a connection got pulled yet. 

[jbower]

Could have bumped the canon plug. Kind of what it sounds like to me anyways

[electricjohn]

Try turning key on first, then inserting jumper across A & B.  Also make sure + side of diode is in terminal F. If everything is normal, it should blink code 12.  My under dash beeper beeps in unison with the diode flashing.

[jfw432]

13 hours ago, jbower said:

Could have bumped the canon plug. Kind of what it sounds like to me anyways

Well I've unplugged and replugged all the connections I could find including the canon plug which was a huge PITA. The 3 fuses under the electronics cover are good as well. Still nothing. I have a breaker panel under the throttle and all of those are good.  I plan to create a new thread for this issue.

1 hour ago, electricjohn said:

Try turning key on first, then inserting jumper across A & B.  Also make sure + side of diode is in terminal F. If everything is normal, it should blink code 12.  My under dash beeper beeps in unison with the diode flashing.

Yeah I've tried every combination. I do remember something buzzing with every flash last time using this same setup but nothing this time. At least this code reading problem was present before I started having gauge issues above so I doubt they're related. 

[jbower]

Check grounds in your bell housing bolts to make sure they are tight and clean 

[jfw432]

MDC is dead. Probably was on the way out already since my hour meter died last weekend. Did all the checks per http://www.epicmarine.com/docs/MDCtrouble.PDF and everything points to a dead unit. Considering how expensive those things are, I may try to swap to a standard gauge setup. 

I did order a new coolant temp sensor. 

[jfw432]

Ok new gauges are installed (irrelevant for this issue) along with a fully functioning coolant temp sensor....still have the same problem.

 

I'm attaching a video of the problem showing the lag in throttle response and the "missing" when it gets to a high enough speed. This video was shot after 2-3 minutes of driving and most of the problems had already gone away. When the engine gets warmed up, both of those issues go away. The throttle lag is still kind of there when launching from idle but it's very minor. Any ideas what is causing this?

 

[Woodski]

@jfw32:  so are you saying that when the engine is warmed up, everything runs fine?  If that is the case, I would think it is sensor related restricting fuel flow.  Hard to tell, but another option might be some sort of odd electrical short or poor connection keeping the injectors from working properly and sporadically not working or perhaps some corrosion on the distributor cap/rotor.  BTW, nice looking dash setup.

[jfw432]

1 hour ago, Woodski said:

@jfw32:  so are you saying that when the engine is warmed up, everything runs fine?  If that is the case, I would think it is sensor related restricting fuel flow.  Hard to tell, but another option might be some sort of odd electrical short or poor connection keeping the injectors from working properly and sporadically not working or perhaps some corrosion on the distributor cap/rotor.  BTW, nice looking dash setup.

That's correct. Once the engine warms up, it runs fine. I know I've changed the MAP sensor, TPS sensor, knock sensor, and the cap and rotor when I was trying to diagnose what ended up being an exhaust leak last July. I've since changed the coolant temp sensor which was bad but didn't make any difference. Short of the oil pressure, is the only other thing the ECU? I would think if something like the intake manifold gasket had a leak, it would show up on one of the spark plugs/pistons but they all look the same. 

 

Thanks on the dash. Hoping to do the switch panels soon as well so I can actually identify what all those switches are. There are too many unlabeled switches and switches labeled "aux" which isn't helpful. 

[jfw432]

Ok so I forgot that I had to unplug the little oil pressure sender to get codes from the MEFI. I did get a code of 44 which means the knock sensor is inactive. I know I replaced the knock sensor last summer though but since it is a drain plug, could I have messed it up when I unscrewed it?

[Woodski]

The injector seals are all good and not leaking causing a potential lean mixture?

[jfw432]

3 hours ago, Woodski said:

The injector seals are all good and not leaking causing a potential lean mixture?

I haven't pulled the injectors to verify but I would think either fuel would be coming out or one of the spark plugs would be whiter than the others and I'm not getting any of that. 

 

I'm beginning to think this is a problem every time I start up the boat after sitting for a day or more. It's just that the longer it sat and possibly the less water is in the engine, the more noticeable it is. If I only let the boat sit for a week or less, I don't typically go full throttle for a few minutes anyway and that's where the problem is...above 37mph. If I drain the water and try to start it, the problem is more noticeable and creeps up at take off and then around 25mph. The longer I run it, the higher the speed it takes to produce the problem. 

[MadMan]

On ‎3‎/‎4‎/‎2016 at 6:44 PM, jfw432 said:

Still can't read any codes for some reason. LED on terminal E and F and jumper between A and B. Turn the key to "on" and the LED just stays on. 

 

Malibu/Indmar connects this LED output together with the low oil pressure sending unit.  This is done to sound a warning if there is an MEFI problem or low oil pressure.    Without the engine running the low oil pressure warning is on, keeping your LED on.  Just disconnect the wire going to the oil pressure sending unit to allow the LED flash codes.  It's the smaller of the 2 oil pressure sending units. 

[jbower]

Did you ever check the fuel pressure?  What motor is it and does anyone know the redline sounds like a rev limiter to me in the video but unsure about 4500rpm

It also may have a hesitation with a knock sensor code. Not positive but I would think it would retard the timing with that code present 

[jfw432]

13 hours ago, jbower said:

Did you ever check the fuel pressure?  What motor is it and does anyone know the redline sounds like a rev limiter to me in the video but unsure about 4500rpm

It also may have a hesitation with a knock sensor code. Not positive but I would think it would retard the timing with that code present 

It's the Monsoon 325 engine with MEFI. I've checked the fuel pressure several times over the last few months. I can't remember what the readings were at idle, full speed, and under heavy load but they all seem to be fine every time I've checked it.

It can't be the rev limiter because as the engine warms up, the point when the stumble happens progressively gets higher in the rpms until it eventually goes away. 

I do agree that the knock sensor seems to be the one issue that has never gone away on this boat. I have replaced the knock sensor with one from the auto parts store with no change but never forked over the $80 for an Indmar knock sensor. No telling if that would actually fix it or not though since it seems like some reputable online stores charge the $60-$80 for the same part number as the $15 one at the auto parts store. 

I do run 87 octane fuel in this boat instead of the recommended 89 octane but I've never heard of that giving people problems. 

[jbower]

My last guess would be to check the tps 

[jfw432]

3 hours ago, jbower said:

My last guess would be to check the tps 

Changed the TPS last fall....didn't make any difference. 

[oldjeep]

1 minute ago, jfw432 said:

Changed the TPS last fall....didn't make any difference. 

did you remember the new cover sheet?

[jfw432]

Just now, oldjeep said:

did you remember the new cover sheet?

Cover sheet?

[jbower]

Not sure if it is adjustable but typically they need set 

[oldjeep]

9 minutes ago, jfw432 said:

Cover sheet?

. sorry, sitting watching office space.