I'm currently planning out a MegaSquirt build for my 1985 Chevrolet Caprice with a 305 V8 using a TBI unit from a 305 Camaro. I want to use a MS3 system because of the USB compatibility and built in data logging. I'm also interested in switching to a crank trigger ignition system later on.
I'm interested in using one of the DIYautotune relay boards because while my car has an ECU, knock sensor and electronic distributor, it doesn't have an electric fuel pump and relays for this. However, all the wiring diagrams I'm finding for the relay board show no provisions for a knock sensor input. It also seems like I'd really be wasting the MS3's inputs and outputs since it doesn't look like the relay board supports any of it. Am I getting this right? If I want to keep my knock sensor, would I be better off building my own power relay box for the fuel pump and any other relays I need? I want to keep the knock sensor because this is primarily a street driven vehicle that I plan to run on 87, but I still want to extract as much power as I can out of it.
Relay Board and Knock Sensor?
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GeorgePatches
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chips60bug
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Re: Relay Board and Knock Sensor?
I have never used a relay board in any of the ms installs I've done. I just wire in the relays using the diagrams. I like to get relay sockets to make the wiring cleaner. My current install has a 3 fuse boxes, one with 14 circuits, and 2 with 6, and at least 7 or 8 relays in play. I have an MS3-pro, in an aircooled vw bug. I'd be shooting my self if I was trying to base everything around a relay board. I was in a similar boat back in my Ms3/3x days. Just go from scratch. Is a little tougher to start, but worth it in the end.
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jsmcortina
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Re: Relay Board and Knock Sensor?
Agreed. The relay board was designed for fuel-only installs that used a V2.2 mainboard.
James
James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk
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My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
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GeorgePatches
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Re: Relay Board and Knock Sensor?
Wow, that sounds like a lot more relays and things going on than I will have. Thanks for the advice, I will make the effort to build out my wiring harness. Do you guys have any advice on a generic fuse boxes or anything I should buy to use for the build? Pretty much everything in the stock ECU and wiring harness is an emissions control device so I'm planning to remove as much of that as I can.chips60bug wrote:I have never used a relay board in any of the ms installs I've done. I just wire in the relays using the diagrams. I like to get relay sockets to make the wiring cleaner. My current install has a 3 fuse boxes, one with 14 circuits, and 2 with 6, and at least 7 or 8 relays in play. I have an MS3-pro, in an aircooled vw bug. I'd be shooting my self if I was trying to base everything around a relay board. I was in a similar boat back in my Ms3/3x days. Just go from scratch. Is a little tougher to start, but worth it in the end.