Setting MEFI 3 base timing

[britandy]

I am hoping someone who has first hand knowledge of setting base timing on a MEFI 3, 7.4 MPI engine can answer a couple of questions. I know what the procedure is and I tried it last weekend, but suspect it did not work as it should.

1. When I shorted the A and B pins together I did not notice any change in engine RPM, and also no change when I disconnected them. From what I have found on line and on Club Sea Ray is when in service mode the ECU will control the engine rpm raising it to around 1000 rpm. What is meant to happen when shorting the pins?

2. If the ECU is truly in service mode I assume I should not have to move the throttle during the procedure, in fact the throttle should be fully closed?

I wonder if the pin in the diagnostic connecter that is meant to be connected to ground on my boat is not.

I plan on messing with it again this weekend but at least wanted to know what other people have experienced.

Thanks, Andy

 

[scoflaw]

My Mefi-3 does not alter rpm when in service mode. Put the rpm's at 1800 manually. Point and shoot

 

[britandy]

scoflaw, thanks, that is what I suspected, I need to open up the throttle. Setting is 8 degrees BTDC, correct? Or have you experimented with a slightly different setting?

 

[scoflaw]

I use 8, never tried 10

 

[370Dancer]

+1 on 1999 GenVI Mag MPI Horizon inboards
No auto increase in throttle.

 

[Kevinkan89]

I’m doing the same process on my 5.7 mpi but I have not see any video how to set the base timing I did TDC on the compression stroke of number 1 cylinder and reinstall the distributor with the rotor pointing at no.1. I not sure if I need to jump A and b with the paper clip any one have a pict how the connection looks like

 

[scoflaw]

What year engine? Is it a Mefi?

 

[Kevinkan89]

07 5.7 mpi mag on a new rebuild motor

 

[scoflaw]

You have the 555 ecm. No A,B on that one. What your doing is correct and the computer will handle the timing from there.

 

[Kevinkan89]

Somebody else tell me that I still need to get a scan to to make sure everything is on the right way I’m gonna get a time light to check how is the timing

I know they computer adjust the timing and there is no way to do adjust the timing only with the computer software thanks for your help