misfiring/running rough

[lucky7's]

I have a 2002 mercrusier 6.2 mpi. Was out running about 4500 rpms and heard some poping and clinging noises all of a sudden in the engine compartment. Then i notice a loss of power. I brought it down to idle and it would barely run and it was misfiring. No audio warning alarm went off or anything. I assume it is either the distributer cap is corroded or the fuel pump is going out. Whats the best way to diagnose this problem.

 

[Bondo]

Re: misfiring/running rough

I assume it is either the distributer cap is corroded or the fuel pump is going out.
Whats the best way to diagnose this problem.

Ayuh,... To diagnose the corroded distributer,...
You just gotta Look....

Start it up,+ chase the Noise.... Maybe it's a catastrophic failure of hard parts...
Maybe a compression test,..??

 

[lucky7's]

Re: misfiring/running rough

Yea hope its not internal. The last thing i want to do is pull a head or something. It was only making noise when you try to give it gas. I had a similar problem at 300 hrs. when the fuel pump went out. Heh it sounded like it was striping its gears when it primed so thats how i figured that one out. I got 700 hrs. on it now so maybe the fuel pump is due again... Seems really rediculous if it is.. I cant believe I only got 300 out of the first one.

 

[lucky7's]

Re: misfiring/running rough

Ok guys got it fixed!! The distributor cap and rotor was corroded up. Pulled it apart and cleaned all the electrodes with some fine sandpaper and put it back together and no more misfire.. Saved myself 50 bucks instead of buying a new one. That would of been the third one replaced because of corrosion. Must be an inherent problem with these engines. Well I think I deserve a promotion, 700 hrs., done all the maintenance myself , and still running.

 

[Bondo]

Re: misfiring/running rough

Ayuh,.... Cool,... Glad it worked out....

You probably otta figure out Why it's happening,...
Alotta water in the motor room or What,..??

 

[lucky7's]

Re: misfiring/running rough

Well I know it gets wet back there when I have alot of people swimming in out of the back of the boat. When they get in and out the water drips through the engine cover lid between the lid and the transom. There is a gutter back there but it does not work very well. The distributor is right under there. Its also claimed my trim pump bracket.. I run in brackish water half of the time so its to be expected. But all in all Ive kept the corrosion down to a minimum. Well as always thank you for the help! Its always good to have people to talk to and get advise from before you jump in to something.

 

[lucky7's]

Re: misfiring/running rough

Burned intake valves was the problem. So it was running rough!!!