454 MAG EFI MEFI 3 wire harness needed !!
 

I’m almost done with my project and I’m having issues with the engine not intermittently is not allowing full power. I’m going to replace the harness now.

Im in need of Mercruiser shows PN: 861162T1 . It is for a year 2000 454 MAG MPI/EFI with MEFI 3 . ( I believe any of the Mercruiser BBC family from 1998 1/2 - 2000 are all the same)

I can’t receive direct messages, so if anybody has one, please put information below in the thread

did you test your TPS switch , ??

It’s funny you mention that I was going to test that this weekend.

I went ahead and open up the whole wiring harness and found there was about nine wires that were almost disconnected or disconnected. I went ahead and remade most of the wiring harness. The engine runs great however, at 3/4 throttle it doesn’t go any farther the butterfly open so my next thought is to test the sensor. I’ll try to do that this week.

Everything else seems to be in working order and I tested the continuity and all the wires. Everything is good. I have the injectors Flow tested everything is good there.

The motor is fully rebuilt with full compression 8° advance, timing, now error codes.

I’ll find out this week. I’m glad to see someone else thinking the same thing I am.

Can you explain this more clearly ?

Everything seems to run perfect however, the engine doesn’t to go to full power and it goes up from 2800-3400rpm slow.

when I’m at 3/4 of a throttle or full throttle it stays the same RPM. It doesn’t go any faster I don’t hear any difference in the engine it doesn’t bog down just doesn’t go any faster so I’m assuming you’re right that is the throttle position sensor issue or wiring around that section.

Plenty of times the at 3/4ish throttle mark on the stick, the throttle body is actually at WOT. You need to see if the throttle body butterflies are fully opening.