Mercru 350 mag mpi ski

[hondon]

Re: Mercru 350 mag mpi ski

Well it is not.This engine is installed in a Ski Centurion Elite V Drive as a single .Believe me ,if I had the parts to experiment with I'dd be doing it.

 

[Don S]

Re: Mercru 350 mag mpi ski

I believe you, I ran the serial number to check for previous problems and service bulletins and anything else that might help in tracking down the problem and seen it in the Chris and just assumed..........

 

[hondon]

Re: Mercru 350 mag mpi ski

I,ll give you the history of this engine as we sold it new and have done all maint since.It do'es however live at the lake that is 3 hours away during the season largely being looked after and used by this very nice gentlemans kids.Boost pump installed before the boat sold.Belt spacers installed per that bulletin after the first season.Last summer the unit was brought to us complaining of sluggishness and surging .Troubleshot down to the in line filter for the boost pump.Flawless and happy all summer.This unit has 320 hours on it so it certainly is not ignored and do'es not appear to be treated in an undignified manner.I recited that serial # from memory after several conversations with Merc.At 45 that memory is not always flawless but we are on the same page and I think that is right.Thanks and keep em coming.

 

[newport dave]

Re: Mercru 350 mag mpi ski

With the key on, you have 12v on the Coil driver/injector/coil (pink/white wires) power circuit and 5v on the sensor power circuit (gray wires), right? I am sure you verified this already but just double checking.<br /><br />Also, wondering if you are able to tell if the engine dieing after release of the key is due to reaching a certain RPM or does it happen at the exact moment of key release? What happens if you hold the key in the crank position (realize it will be grinding) for just a second after if starts, does it continue to run until you release the key?<br /><br />It seems to me that energizing/deenergizing the circuit to the slave solinoid (intiating cranking) is not the critical factor here, but the RPM may be.<br /><br />Is there a change of modes in the ECM that occurs when a predetermined RPM is reached? For example, a change from module mode to run mode or a change from closed loop to open loop?<br /><br />Dave

 

[Doug Durako]

Re: Mercru 350 mag mpi ski

Hondon---in your first post, you said it was partially "trailer sunk." These folks sound like experienced boaters---what happened? Did they turn in an insurance claim?---might be some coverage here.

 

[Richard Petersen]

Re: Mercru 350 mag mpi ski

I still like MUC's answer best, because I had the same problem on the water and all it was, was the safety tether switch was not holding closed - open what ever. It took 5 tries to get it to hold. If the engine starts and runs as long as the key is in the starter position, GO after the TETHER switch without mercy. Or the tether wiring. Could be tether circuit on computer as a last resort. STAY WITH THE TETHER, MUC is hot. I figured it out when I held the tether switch up by hand and it ran fine. You need some good luck about now.

 

[Don S]

Re: Mercru 350 mag mpi ski

If you also notice in his first post, he bypassed the boat wiring harness completely. That would eliminate the kill switch. He also said it would start, but die........The system you speak of was with points and had a hot start lead off the starter that would bypass the tether switch. But the MPI computer controlled engine is years past that technology.

 

[Don S]

Re: Mercru 350 mag mpi ski

When the engine starts, is should run at about 12 to 1500 rpm for a few seconds then slow to the 600rpm range. Is it running ok at the higher rpm, then dieing when it drops to normal?<br />

Hondon, I ask this earlier and never got a reply. Could you describe in some detail how and when, and for how long it runs before it dies?

 

[MGallik]

Re: Mercru 350 mag mpi ski

Did bypassing the boat wiring harness include the oil pressure switch? Any others not included like drive temp, etc?<br /><br />Just asking, I don't know boats like you folks do.

 

[hondon]

Re: Mercru 350 mag mpi ski

This unit will fire off as expected and if I continue to crank will lope and bounce off the starter.As soon as the key is released to the run postion, nothing but I continue to have communication with the ECM through the scan tool.Here is another little nugget .If I pull the lanyard and crank a few times this thing will give me a couple little farts after the key is released when the lanyard is put back in.It wo,nt fire off but we got something going on.This boat comes with Perfect Pass that taps into the tach signal at the back of the tach.Merc has been interested in that but I would think that ruled out with the boat harness.Jumping that harness only isolates the engine from the boat. All engine harness and sensors will operate the same with that harness out of the picture.It would be interesting to know if that pressure switch could have this effect .Merc says no as the cranking and ignition sides of this engine are entirely independant.

 

[hondon]

Re: Mercru 350 mag mpi ski

Oh ,that serial # is OM311333.Sorry off by 11.Will be stocking up on ginko biloba this weekend.Thanks for the help and keep em coming.

 

[Don S]

Re: Mercru 350 mag mpi ski

As soon as the key is released to the run postion, nothing but I continue to have communication with the ECM through the scan tool

That's normal, as long as the key is in the run position, the Scan tool reads the ECM, not just when the engine is running.<br /><br /><br />

If I pull the lanyard and crank a few times this thing will give me a couple little farts after the key is released when the lanyard is put back in.

Say What?????<br />In your original post you said it started and died, even with the boat harness bypassed.<br />Now you say it farts when you release the key and put the lanyard back in......Do you do that at the same time, and if so, WHY??<br /><br />

This boat comes with Perfect Pass

What is Perfect Pass. Does it hook into the engine anywere also, perhaps a seperate wire for power or something???? Sorry, just never heard of it before.<br /><br />If the oil pressure switch was showing a problem, you would see an oil pressure or engine temp problem on the scan tool. It's first reaction would be to run in safe mode. Was they any oil pressure hits shown on the scan tool?

 

[newport dave]

Re: Mercru 350 mag mpi ski

I'll throw another crazy idea out there.<br /><br />After looking at a parts diagram, I noticed that the crank sensor on this engine is mounted on the lower part of the timing chain cover. It sounds like from the amount of water that was in the boat it may have been totally submerged for who knows how long. Have you unplugged it and dried out the connector and tested the sensor?<br /><br />Dave

 

[hondon]

Re: Mercru 350 mag mpi ski

Item # 1,I know that is normal and it also tells us that we do not have an interuption of communication between the ECM and the engine harness and that we are reading NO faults.# 2,This engine will fire off as normal while you are CRANCKING.As soon as the key is released to the run position we get nothing.In my observations I noticed that if I pulled the lanyard ,cranked the engine over a few times with no ignition,then reinstalled the lanyard and cranked I MIGHT get a couple of little extra farts out of this thing.Oil pressure switch was a response to another post and I thought that would show up on the scan.Perfect Pass is a little like cruise control but it is receiving it's signal from the tach lead which on this unit is controled by the ECM.I have spoken with Perfect Pass about this unit and they insist it could,nt be related.Merc sure seems curious though. Thanks again.

 

[hondon]

Re: Mercru 350 mag mpi ski

Thanks Dave .I keep coming back to that CPS in my mind for exactly that reason and also this engine acts like one that has jumped a couple teeth on the timing chain, do,nt we all think?

 

[muc]

Re: Mercru 350 mag mpi ski

Hi Hondon,<br /> MCM gives test for CPS, disconnect the sensor and measure between A+B = 23.2 mohms, between B+C=23.21 mohms. You might want to do this test and then reconnect the CPS and then disconnect the ECM and repeat test at the ECM connector B pin21+pin1 and pin1+pin10 to rule out a bad wire or splice between the two.<br />Does the Perfect Pass get its tach signal from the dash or does it come off of the gray wire with the bullet connector on the engine? If it’s getting it at the bullet connector on the engine pulling the 10 pin won’t isolate it.<br />One thing that comes to mind is the shift interrupt circuit, some Bravo and MIE ECM’s have this function still active in the ECM and require a bypass plug be installed in the engine harness. Not sure if yours has this, when I look at the wiring diagram Don S posted ( oh and by the way that is one nice scanner you got Don S—very clear--- I’m impressed ) I don’t see a yellow/purple wire coming out of pin 19 of the B ECM connector. If you do have that wire it would be good to check for continuity between pins 1 and 19 at ECM B plug. Maybe this engine is in shift interrupt?<br />Good luck on this problem----- it’s jobs like this that mechanics love and shop owners hate!!!!!

 

[Richard Petersen]

Re: Mercru 350 mag mpi ski

Back to what I said earlyer. When you first time try to start it you get a normal firing in the start position and then instant stop when the key is released to the RUN position right? If you do not turn to OFF, but go back to STARTER position, is that ( second time )when you get the farty or no farts? If yes- my boat does the same. I have to go to OFF for about 5 to 10 seconds. Then I can go thru the whole procedure again. Someone- please loan him a computer. The manufacturer will not or can not help. Down with computers in a toy we like to run now. My boat is stored. Somebody go thru the same sequence I gave, see if you get the same results. Let us know. ASAP. Thanks for the help.

 

[Don S]

Re: Mercru 350 mag mpi ski

I'm becoming very inclined to believe you have a water intrusion problem in the harness at the CPS since it could very well have been under water when the boat trailer sank. With the water up to the stringers, it may very well have been under water.<br />Did you pull the connector and blow out any water and check for corrosion? Not only on the sensor itself, but the plug. Since it's a 3 wire sensor, it works on differences of voltage. While cranking, due to the voltage drop of the engine cranking, and the possible different voltages the ECM is receiving from the CPS you may be getting closer to normal voltages than when not cranking which are totally out of range.

 

[newport dave]

Re: Mercru 350 mag mpi ski

A few more thoughts about the crank sensor;<br /><br />Don, correct me if I'm wrong, but I believe that the cam and crank sensor fault codes can only be set while cranking. If the ECM is not finding a problem while cranking a fault code may not be set, but a fault may still exist. <br /><br />Also, were you just looking at the active fault codes with your scan tool or were you able to retreive the fault history as well?<br /><br />Dave

 

[hondon]

Re: Mercru 350 mag mpi ski

Thanks Muc.I hav'nt seen those specs in any Merc publication but I will certainly check those values out and post results as well as pass them on to Merc.Perfect Pass picks up it's signal at the guage so is out of the loop with the ten pin unplugged .I am not seeing a cam sensor for this unit in any of my diagrams.Working from Mercru manual #36 ECM 555.I plan on mobbing this little problem child tomorrow armed with all the advice I've gotten here.By the way Muc.How's the weather back there?Grew up in Truman between Mankato and Fairmont.