Does anybody have any information as to the degrees of advance and at what RPM's the distributor module operates at? I have looked in all of the obvious places with no luck.Engine is 2002 500EFI. Thanks for any help. Stealth

Its a 3D table for the EFI motors and not a traditional 'curve' or line you might expect. I haven't seen the 500 EFI tables but have seen many others and in general the Merc ignitions curves have relatively high advance in the midrange and tapers off a little at higher rpm / MAP points. Base timing is usually 8 to 10 degrees. High vacuum (think snap idle decel) typically has very high advance to catch the motor at idle and prevent stalling on transition.

Unfortunately its not a cut and dry answer you seek.

Trash Thanks for the reply. Sounds like a whole different ignition system will solve the question.

The timing curve is controlled by the ECM. The ECM would need to be reprogrammed to change the curve.

What are you trying to achieve?

Here's a sample of the 500 EFI Stock Ignition table


RPM* MAP
30 40 50 60 70 80 90 100
5000 28.8 28.8 28.8 28.8 28.8 28.8 28.8 28.8
4800 28.1 28.1 28.1 28.1 28.1 28.1 28.1 28.1
4600 28.1 28.1 28.1 28.1 28.1 28.1 28.1 28.1
4400 28.1 28.1 28.1 28.1 28.1 28.1 28.1 28.1

Tuner Trying to determine if my distributor can be used in a carb. application. Or what is needed to drive the distributor? Thanks

what distributor is it ?? 500 EFI one wont work with a carb ...........not sure what you mean ^^^

F-2 I was asking the question to see if my EFI dist. could be utilized with the elimination of the ECM or what changes would need to be made for a carb. application. Sounds like the whole system would need to be replaced?

Griff Thanks for reply. I do have the factory engine and drive manuals, but it seems a lot of the tech. stuff is not provided in the engine manual.

If the dist in the pic is your distributor - which it should be - you can use it for carb. May need a module (#9) change for this, maybe not. You'll have to see if your module # (GM# will be on the module) has advance built in or not. Some do. Can always hook a Daytona Sensors Marine box (fully programmable curve / revlimiter / idle stabilazation and more) to it too.