Where does this plug go?

newtonx1

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This is an 85 GMC Jimmy with a 96 vortex, carbureted and a 700R4 trans. I have 2 questions. First, this wire harness comes down behind the block, splits off and one plug goes into the transmission. Where does the other go? I've felt up and around and can't find the inlet for it. Any ideas?

Second, the original motor had a mechanical fuel pump, this one's doesn't. The previous owner put an inline pump on it. I can't tell if it's getting enough fuel. The inline pump is an Edelbrock 17303 indicating 30gph. This truck requires 4-7gpm so I don't know if this will work for the application. Thoughts?
 

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PrairieDrifter

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That red connector went to a vacuum switch thing on the passenger side rear of the intake, I believe it had two vacuum hoses connected to it. Beyond that I don't know what it does. I stripped all that stuff.

Not sure on the fuel pump.
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78C10BigTen

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Appears the fuel pump is only good up to 3.5 psi, most carbs need around 6-7 psi if i remember right.
 

bucket

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That 3.5 psi is just where they rate the GPH. It probably has less output at higher PSI, so they don't advertise it. It should make enough PSI to run a carb on a very mild engine, since that's what it is sold for.
 

PrairieDrifter

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I looked back in my build thread as I had this question. It has to do with the torque converter lock up solenoid. That red connector goes to a vacuum switch on the intake as I pictured, then i believe the vacuum lines ran to the vacuum tree on the thermostat housing, this would only let lockup activate once the engine was at a certain temp.
 

newtonx1

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I appreciate the replies. I'm going to get a 5-9psi fuel pump and try again. Seems that little pump doesn't have the pressure needed to keep the truck running.

As for the plug...PrairieDrifter, I appreciate the photo but there's so much going on there I can't tell what I'm supposed to see. This plug splits from a wire harness on the driver side, behind the block. I doubt it has the length to make it back up and over to the passenger side. I'll keep digging. Thanks for the assist.
 

PrairieDrifter

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350, 350, 350, 350, 350
I appreciate the replies. I'm going to get a 5-9psi fuel pump and try again. Seems that little pump doesn't have the pressure needed to keep the truck running.

As for the plug...PrairieDrifter, I appreciate the photo but there's so much going on there I can't tell what I'm supposed to see. This plug splits from a wire harness on the driver side, behind the block. I doubt it has the length to make it back up and over to the passenger side. I'll keep digging. Thanks for the assist.
I circled in green on the left side. You can see a little bit of red at the back of the intake. That is where that plug sits.
 

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