Please, need an EFI wiring harness to fit a 454 Mag (1997)....
got problems in mine with spark/timing control codes showing up & causing idle/dieing problems.
Pls email/msg/call
[email protected]
918-760-1080

Thanks!

Try www.mercrusierparts.com

I did trty them... $1100.00 & I am not SURE thats the problem!! I was looking for good used to troubleshoot it before spending that kind of money.

You gotta find somone converting to a carb set up. keep asking around. Good luck.

I have a couple of harness off 1995 502 efi and also 1999 502 efi,which controller do you have,the mefi ecm have delphi numbers on back of box,from that number i can determine what mefi ecm(1-4) you have,I think that is the only difference in the harness,give me a call Dave 410-956-5381

According to Mercruiserparts.com, all 454 & 502 MPI engines used p/n 84-860226A2 efi harness. No change for any ecm change noted
My ecm is a MEFI 1 per Arizona Speed that did my mapping.
I'll call tomorrow!
Thanks.

The MEFI1 and MEFI3 (MEFI2 was never used in the 502) wire harness's are different. The MEFI1 had a seperate knock module and different ECM pinouts.

Interesting... what years were the MEFI 3 used??

MDGPerformance- Dave, I called that # & a woman did not want me to talk to you, so I left a call back message.
George 918-484-2715

860226A2 is the correct number for a MEFI1 equipped 454 and 502 Mag.

861162T1 is for the MEFI3 ('98 1/2 model year, serial # 0L086001 and above) 454 and 502 Mag.