Engine alarm couple times today

[oldjeep]

And last night the alarm came back, but with a difference.  Same cylinder 3 misfire code, but this time it was actually misfiring.  Shut the engine off and restarted and then it ran fine for another hour or so of runtime.  I think this just told me that it is either the injector, injector connector or wiring to the injector.  That is the only thing I can think of that would impact a single cylinder randomly that would go away on a restart.

So, I guess after I pull the data tonight I'll pull the connector, clean it up with some contact cleaner and then put some dielectric grease on it.  Not sure how much more if any use we will get out of the boat this year, but when I winterize it I may either pull injector 3 and send it in for reconditioning or just swap 1 & 3 and see if the issue pops up on cylinder 1 next year.

 

Nothing interesting here:

Active Trouble Code List: 1

       

      1. SPN: 65593  Cylinder 3 Misfire

         FMI: 7  Mechanical system not responding or out of adjustment

         Occurrences: 3

         Freeze Frame Data for SPN: 65593, FMI: 7

            Boost (MAP)......................... = 25.96 inHg

            Engine Speed........................ = 4551 RPM

            Coolant Temperature................. = 165.20 °F

            Vessel Speed........................ = 38.31 MPH

            DTC Fail Hour Meter................. = 226.90 hrs

            Engine Run Time..................... = 0.14 hrs

            Throttle Position................... = 55.1 %

            Raw PPS1 Sensor..................... = 2.12 %

            Raw PPS2 Sensor..................... = 2.12 %

            Startup Coolant Temperature......... = 149.00 °F

            Barometer........................... = 28.91 inHg

            Ignition Voltage.................... = 13.44 VDC

            Powertrain Relay Voltage............ = 14.21 VDC

            Oil Pressure........................ = 67.9 PSI

Edited October 11, 2016 by oldjeep

[oldjeep]

Another year and more misfire codes.  Had a cylinder 3 misfire the first time we took the boat out this season after some heavy acceleration, reset the code and it went away for the next couple times out.  Last Sunday the code was back again (or so I thought) so today I swapped the 1 and 3 injectors to see if the code would follow.  Went to clear the previous code and it was a cylinder 1 misfire - crap, guess I wasted time swapping the injectors.  This is the first time it has been anything other than cylinder 3.  Since I had the plenum off I also swapped a brass cap and rotor on, since the last time I changed it all I could get locally was aluminum.  The cap and rotor didn't look too bad but it was a lot more wear than I would have expected from 51 hours.

Guess we'll see what happens next.  Won't get the boat in the water for another week at least with the weather the way it has been.

[skurfer]

Check where the cap screws go into the distributor. IIRC it's plastic, sometimes people use the wrong screws and it cracks the female base on the distributor. You need to be able to inspect both sides, look for a crack, if there is this, the screws might not keep the cap tight, causing misfires and the need for a new distributor. 

[skurfer]

While you're at it and you have diacomm, get on the horn with Indmar (have your serial # handy) when you're running the boat and make sure your timing is set properly. Very easy to check, Indmar can walk you through it over the phone. Cam angle needs to be a certain # over 1,200 RPM's..

[MadMan]

Intake manifold vacuum leak @cylinder #3?

[oldjeep]

8 hours ago, skurfer said:

Check where the cap screws go into the distributor. IIRC it's plastic, sometimes people use the wrong screws and it cracks the female base on the distributor. You need to be able to inspect both sides, look for a crack, if there is this, the screws might not keep the cap tight, causing misfires and the need for a new distributor. 

up until last season it had the factory cap on it, so I'm confident that the screws were right size.  The new caps came with oversized screws that could be used if the originals had stripped, but I used the originals.  Hopefully I have not cracked anything while replacing the cap as that would be awful hard to see in a vtx without removing the plenum.

Edited April 30, 2017 by oldjeep

[oldjeep]

1 minute ago, MadMan said:

Intake manifold vacuum leak @cylinder #3?

seems unlikely due to the design of the intake/plenum but I guess I could eliminate that possibility easily enough with an unlit propane torch.

[oldjeep]

8 hours ago, skurfer said:

While you're at it and you have diacomm, get on the horn with Indmar (have your serial # handy) when you're running the boat and make sure your timing is set properly. Very easy to check, Indmar can walk you through it over the phone. Cam angle needs to be a certain # over 1,200 RPM's..

ill check into that.  Pretty sure I've got the full indmar manual and some logged data that I could already check the cam angle on at a variety of rpms.

[oldjeep]

Found the manual and the cam angle spec is interesting.  705 degrees +- 5 degrees.  I guess since the cam spins at half the rate of the crank it makes sense that you can be over 360 degrees, but still seems weird.  Need to track down those data files now.

[oldjeep]

I only had a couple minutes of logged data above 1200 RPM, CAM angle and W Cam angle was 706-708.  Looks like I'll need to just let it log for a long time the next time we are out and see if it gets up above 710 at some point

[Malibuguru0515]

Ive seen bad caps right out of the box, sorry its a pain.  whats fuel pressure?  should be 60psi for 2012 pump in tank, at all throttle positions even under load.  i like MSD 8017 cap, its got brass contacts!  better than corrosion sucking aluminum... the cap does not have to be Marine. the stock caps are just stock GM caps... the distributor assy is what has to be Marine rated.  try to dig into the Indmar manual. I think they even say a dinged prop can cause a misfire fault! vibration carried all the way to motor and knock sensors detecting a false knock and mis fire!  try swapping your knock sensors from side to side. I'm just spit balling here...  I've never seen a bad prop cause a mis fire. but i believe its in the manual.

[z3cta]

On 9/22/2016 at 8:01 PM, oldjeep said:

Probably not, the real time value (engine off) is also -40F. I'd think it would be throwing a separate code if it thought that was invalid.

Won't have time to actually run the motor until next week and do some data logging.

Hello, have you ever figured out the -40 on your manifold air temp? I am having the same temperature reading along with a misfire on cyl 2

[oldjeep]

3 minutes ago, z3cta said:

Hello, have you ever figured out the -40 on your manifold air temp? I am having the same temperature reading along with a misfire on cyl 2

There just isn't a sensor for manifold air temp (not supposed to be).

[oldjeep]

I should also say that my intermittent misfires have never gone away.  It is pretty consistent about the conditions when it will happen.  Only happens over or around 40 mph, and even then it only happens a couple times a year.

Cap, wires, plugs have been swapped.  Injectors have been switched around. 

I gave up trying to track it down, always wondered if there was a software update for the MEFI since mine was an early build 2012 but have never really looked into it.  Should have asked @Engine Nut when he was around the forum a lot.

[UWSkier]

You can still email Larry and he'll typically respond same day if it's a business day. Helped me out last month with a fuel regulator config question. 

[oldjeep]

23 minutes ago, UWSkier said:

You can still email Larry and he'll typically respond same day if it's a business day. Helped me out last month with a fuel regulator config question. 

Maybe I'll do that.  It isn't something I think of too often, the little laptop and Diacomm cable is in the boat so when it has happened I just stop for 5 minutes and reset it.

[oldjeep]

So today I took the boat to the dealer, for the 2nd time ever.  I emailed back and forth with Larry this winter and found out there was a new program for the ecu in 2015 to take care of the overly sensitive misfire alarms.  It reinforced why I hate having anyone service anything, but I hope it fixed the problem for good.

[oldjeep]

Finally got the boat on the water today.  40+ mph for a couple miles, no alarms.  It is about time.  

[oldjeep]

Definitely fixed.  We were out for a few hours yesterday in conditions that would have caused the alarm.

So - for anyone who gets random misfire alarms in a 2012 - 2013 5.7L - might check into getting the ECU firmware updated.

 

There was a "misfire" calibration developed for 2012/2013 model engines with MEFI 6 ECM's like yours. Your dealer has access to those calibrations from our website. 

Edited June 7, 2021 by oldjeep

[justgary]

1 hour ago, oldjeep said:

Definitely fixed.  We were out for a few hours yesterday in conditions that would have caused the alarm.

So - for anyone who gets random misfire alarms in a 2012 - 2013 5.7L - might check into getting the ECU firmware updated.

 

There was a "misfire" calibration developed for 2012/2013 model engines with MEFI 6 ECM's like yours. Your dealer has access to those calibrations from our website. 

Who knew that occasional visits to your dealer could actually provide a useful outcome?  

[oldjeep]

18 minutes ago, justgary said:

Who knew that occasional visits to your dealer could actually provide a useful outcome?  

I'd buy a canoe if I had to go in to the dealer very often.  Thing that bugs me is that this should be a TSB that you get notified about.

Edited June 7, 2021 by oldjeep

[formulaben]

1 hour ago, oldjeep said:

Thing that bugs me is that this should be a TSB that you get notified about.

Agreed.

[JWK]

oldjeep I am having the same issue are you 100% the update will fix this issue? I’ve done everything smh 

[oldjeep]

19 minutes ago, JWK said:

oldjeep I am having the same issue are you 100% the update will fix this issue? I’ve done everything smh 

For my 2012 it 100 percent fixed the issue.  No alarms in 2 years 

Edited June 18, 2023 by oldjeep