building a harness

FreeEMS topics that aren't specific to hardware development or firmware development.
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DeuceEFI
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Re: building a harness

Post by DeuceEFI »

Clarification on the Oil Pressure Switch (OPS) setup on the S10:

The Oil Pressure Switch is in series with the 12v positive supply to the fuel pump relay and the factory ECM is still in place in that circuit for the time being, which bypasses the OPS during key on, supplying 12v to the fuel pump relay. The firmware/Jaguar board supplies the connection to ground through the Fuel Pump FET (Low Side Driver) completing the electrical path to allow the fuel pump relay to be energized.

I need to finish the wiring harness modification to get rid of the factory ECM/Oil Pressure Switch as I don't see the truck leaving my possession any time soon. It is too much fun! :-)
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Fred
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Re: building a harness

Post by Fred »

andg wrote:So for my setup using the 3x signal I have a few things to determine. Do I need bigger injectors? Will I be using sequential injection or pairs? Will there be a different state at idle
Stock injectors are fine.
Pairs for now, but run all 6 wires all the way to the board if you're doing a new loom.
No special idle state, no.
I'll settle for a switch if I have to. I'll likely figure out something easy for the fuel.
It should be straight forward to gain control of the relay in some form or other :-)
I also have a test port that I have a flexible hose attached to that I can pull the plug out really easily so the engine can stay running at fast idle while I'm outside of it.
<snip>
I have a vacuum line that runs through my harness. It will have a plug and go to the test port. I can control it from inside the vehicle without too much trouble, thanks.
Or inside of it! Mine would hiss under boost if I forgot to close it :-)

Fred.
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Ronin7
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Re: building a harness

Post by Ronin7 »

Fred wrote:Hello and welcome, Nathan!

Sorry to be obtuse, but ask again end of next week and there will be more info on that subject :-)

Fred.

Fred/Andy,

It was mentioned there might be some movement on the Jaguar front by the end of this week- any news? Would love to get my hands on a PCB. Just scored this on craigs list for $50 so I have another tool for diagnosis/development:
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Saleae Logic 8.jpg
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Fred
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Re: building a harness

Post by Fred »

Good score! :-) I'll point Andy here and he can fill you in, or PM you, or whatever he chooses.
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DeuceEFI
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Re: building a harness

Post by DeuceEFI »

Nathan,

Nice score from craigslist, I have a Saleae Logic as well :-)

Before I sell anyone a Jaguar 0.4-alpha board or kit I would like to first test it on the FreeEMS S10, I have already found two small errors in the pad connections for the surface mount AAP and MAP sensors, but if you are going to use an external MAP sensor this isn't an issue.

I'll update my "Jaguar 0.4-alpha PCB Status (was Jaguar A4 PCB Status)" thread viewtopic.php?f=67&t=1810 soon with the testing progress and some photos. :-)
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Re: building a harness

Post by Ronin7 »

DeuceEFI wrote:Nathan,

Nice score from craigslist, I have a Saleae Logic as well :-)

Before I sell anyone a Jaguar 0.4-alpha board or kit I would like to first test it on the FreeEMS S10, I have already found two small errors in the pad connections for the surface mount AAP and MAP sensors, but if you are going to use an external MAP sensor this isn't an issue.

I'll update my "Jaguar 0.4-alpha PCB Status (was Jaguar A4 PCB Status)" thread viewtopic.php?f=67&t=1810 soon with the testing progress and some photos. :-)

Cool- I subscribed to that thread. I will most likely be using the stock GM MAP sensors unless there is a strong reason not to so the Pad errors are no big deal for me anyway.

Thanks,
Nathan
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