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-   -   1998 Mercruiser 7.4 L EFI Timing (https://www.offshoreonly.com/forums/general-q/158360-1998-mercruiser-7-4-l-efi-timing.html)

JIM H 05-15-2007 10:33 PM
1998 Mercruiser 7.4 L EFI Timing
 
How do you adjust the timing on this engine. If you dont have the mercruiser scan tool ?

Thank you

lowfunds 05-16-2007 06:59 AM
you cannot do it without the timing tool or the ddt scan tool. i'm in amityville also if you want my job can get you the timing tool from mercury. stop in at Delmarine on ketchum avenue.

Dave_N 05-16-2007 10:14 AM
You can do it and it's easy. Assuming your '98 is MEFI 2 or 3, with the engine idling, you put a jumper (small paperclip works well) between terminals "A" and "B" on the DLC (Data Link Connector). That puts it in BaseTiming Mode. Then set timing with a timing light.

Just in case, if the engine does not rev up when you put the jumper in but instead dies, you may have a MEFI 1 system in which case you would need to run the engne up to about 1600RPM before you put the jumper in.

Dave

Elite Marine 05-16-2007 04:17 PM
Originally Posted by Dave_N (Post 2129584)
You can do it and it's easy. Assuming your '98 is MEFI 2 or 3, with the engine idling, you put a jumper (small paperclip works well) between terminals "A" and "B" on the DLC (Data Link Connector). That puts it in BaseTiming Mode. Then set timing with a timing light.

Just in case, if the engine does not rev up when you put the jumper in but instead dies, you may have a MEFI 1 system in which case you would need to run the engne up to about 1600RPM before you put the jumper in.

Dave
EXACTLY!!!

28Eliminator 05-16-2007 05:10 PM
Originally Posted by Dave_N (Post 2129584)
You can do it and it's easy. Assuming your '98 is MEFI 2 or 3, with the engine idling, you put a jumper (small paperclip works well) between terminals "A" and "B" on the DLC (Data Link Connector). That puts it in BaseTiming Mode. Then set timing with a timing light.

Just in case, if the engine does not rev up when you put the jumper in but instead dies, you may have a MEFI 1 system in which case you would need to run the engne up to about 1600RPM before you put the jumper in.

Dave
Dave is right on. I have a MEFI 1 and I have done it several times. Have fun!:

JIM H 05-16-2007 07:47 PM
Thank You Guy's

I'll let you know how i make out


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