mercruiser mx6.2 mpi

[goingindebt]

i just purchased a donzi z32. this boat has twin mx 6.2 mpi,s with 200 hours and is in new condition. its been sitting for a year now. after installing new batteries I tried to fire it up and found when turning the key on nothing happens, fuel pumps don't kick on or I don't hear anything. both motors crank over fine but there is no spark to plugs or coils. both engines do the same thing so I figured its the lanyard switch but it tests ok. any ideas where to start? thanks

 

[Scott Danforth]

welcome aboard.

Not sure, however it sounds like you may have a connection issue.

 

[alldodge]

Howdy

Start by check for power at the stop switch, then go to the coil and check for power at the key switch the "I" terminal. Then pull the engine connecter and check for 12V at terminal 5. If that checks out there will be 2 relays and 3 fuses on the motor, check the fuses and swap the two relays (they are both the same. Small square shape

 

[alldodge]

Just thought of something, your not going to be able to read 12V at pin 5 with the connector removed. Check for 12V at the coil connector

 

[thumpar]

Do your gauges work?

 

[goingindebt]

thanks for your help guys. I had 2 different marine mechanics there today and both said that both ecm's are bad. how this could happen at once is beyond me. im finding new is 1800. ive spoke to 2 different shops which state they can repair them as most of the time is a ground problem. I also see used ones on ebay but there are variations on part numbers. I found a used one with the same part number but for a 350. I can only assume it might work but have timing and other issues. does anyone have any advice weather to buy new or are the repair shops for ecm's reliable.

 

[thumpar]

I doubt both went bad at the same time. If you want to try it I would try one first. Buy it from the mechanic and make them guarantee the fix or full refund. If that fixes one then do the other. ECMs don't go bad that often, not that is doesn't happen but it is rare.

 

[alldodge]

I had 2 different marine mechanics there today and both said that both ecm's are bad

No way, you need to run away from those guys. If ou can do some checking we can help. Before just buying another ECM have it checked out. FUNTIMES knows the company you should send it to. I think it's mefiburn, he should show up soon

Agree with thumpar, are your gauges coming on when the key is turned on?

 

[Fun Times]

FUNTIMES knows the company you should send it to. I think it's mefiburn, he should show up soon.

I didn't receive any notifications then I realized the spelling wasn't the same. Seems there was a similar user name but with all capital letters and run together while my username is spaced between FT. Then watch out for a many time recurring past forum member that possesses a sense of humor by adding SR to the end of FT after I found him.

goingindebt, Did they by chance inform you as to what tests were performed to determine both ECM's were bad?

What year is the boat/engine? Engine serial number handy?
Any signs of damage that may indicate the boat being hit by lightning? Lightning could damage the ECM's.
Accidently connecting up a battery in reverse could cause some ECM damage too.

In your diagnosing of the 12 volt electrical systems, Using the diagram above in post 3 and this video, try bypassing the boats wiring harness to see if the engine will prime the fuel pump and spark at the coil while cranking.
https://www.youtube.com/watch?v=NUoXFIo2Ab8

What two ECM repair companies did you call?

 

[goingindebt]

thanks for your responses once again. my last mechanic saw a burnt hole in the bottom of the hull and is convinced that the boat was struck by lightning. neither tach gauges move when you turn the key on. the mechanic put on a ecm which was not an exact match for for serial number but the fuel pump did come on but it still didn't have spark. he says chances are it will need more than ecm's. nice video Funtimes, should I be able to start this 6.2 the same way? It looked liked that motor's electronics were a little older. also I saw a few places online that claim they repair emc's, would anyone have any thoughts on this type of repair?
one of the companies that claim they repair these are Wipple Superchargers. the other was just a random google search.
these motors are 2003 with less than 200 hours.

 

[Fun Times]

Yes if ever needed you could start your engine like that as the wiring plug connector will be the same right up until 2005. Staring the engine that way is a good test to help eliminate the helm electrical components or connections as being part of the no start issue. Since another ECM powered up the fuel pump by turning the ignition key on, you shouldn't have to jump connections like that at this point.

Also since you had no spark while cranking with the other ECM, lightning strikes typically tend to damage the Crankshaft sensor which would not allow any signs of spark by not sending any reference signals. Your RPM gauge should be moving to around 350 RPM while cranking....The RPM signal basically starts at the crank sensor.

Search online images, 'boats hit by lightning damage' to see if your boat appears to have close to the same type of damage...http://www.bing.com/images/search?q=...mage&FORM=AWIR

Your engine serial number is not visible on the flame arrestor cover so you may want to try looking for them just above the engine starters on the starboard side. The tag should look like this,

Your boat, engine year models/serial numbers were pretty close to a transition time frame for parts changes so in order to find the proper part numbers without guessing, you'll want to find the serial numbers if possible.

Being that you have the 555 ECM's, there's only one company that I can recall that offers testing and some repairs only if possible for this design ECM and that is Wipple Superchargers. Other companies are setup to repair the older MEFI style ECM's which won't be of much help to you. You may want to try calling them back to see if they've been successful with repairing lightning strikes but they may need to open the ECM up to see the damage though.

Another option would be your boat insurance may cover all the repairs.

Keep us updated and good luck.