99 250 EFI Dropping a Cylinder

[24gradyexp]

I've got a 99 250 EFI Merc with an intermitten ignition problem (Cylinder cuts out then comes back then will cut out again like someone flipped a switch. Could it be diagnosed by hooking up to test equipment at a dealer or should I just do the old process by elimination theory. With that should I disconnect and ground the sparkplug or the disconnect the plug from the ECU and Stator to the coil.<br /><br />Thanks

 

[Perfidiajoe]

Re: 99 250 EFI Dropping a Cylinder

Is it the always same cylinder? If so I would switch coils w/ another clyinder & see if the problem moves. If it does you probably have a bad coil. If the problem remains w/ the original cylinder, I would bet on the stator being bad. Good Luck, Joe

 

[24gradyexp]

Re: 99 250 EFI Dropping a Cylinder

I don't know what cylinder it is yet, Does not do it all the time. I was just wondering if the if the Mercury DDT would tell met that to save me time. I would just have the marina pay the marina to hook it up fee rather than spend the time trouble shooting it . It is a brand new stator as I previously had a bad stator coil on # 3. I suppose I could just put a new spark plug coil in one place and rotate it from there but was looking at saving some time using the DDT

 

[Perfidiajoe]

Re: 99 250 EFI Dropping a Cylinder

If you are willing to pay the diagnostic time bill, a good mechanic can pinpoint your problem. I was just trying to give a few sugestions on doing it yourself to hopefully save a few bucks. If you have a good mechanic that you do business with, & the time is worth more than the money to you, then by all means give him the job. Or maybe you'll watch him and pick up a few tricks, that can be worth more than the money. Good Luck, let us know how it turns out. Joe