Getting a little fancy... 1987 V10

[frotosride]

So I finnaly have felt good enough to run the fuel injector pins and swap the coil harnesses. Now I have plenty of length to mount the PCM in the cab. I will certainly have to shorten several but that will happen last. Now I will be consolidating grounds and all time hots. Then weld a run stand and pray the weather clears up enough to drop this thing in or at least work on the fuel system. It snowed for the better part of the day today so we will see.

[frotosride]

Going to do some measuring tonight to make sure I got plenty of room before I wrap anymore up with tape. I should be good but I want to prevent any hickups come install time BC I will likely be moving shortly after.

[frotosride]

I may just be over thinking but where is the oil pressure switch that completes the fuel pump circuit on the TBI, once the engine is running? It is separate from the gage sender right? I wanna keep this switch and adapt it to fit on the 6.0 to maintain the fuel system wiring. Thanks in advance...oh and pic would be nice.

[Captkaos]

Typically it is above the oil filter.

[frotosride]

Thanks Cap..now I'm a little confused on what the switch actually does.  Is it still controlling the fuel pump relay keeping it switched on? The diagrams that I find all suggest it supplies power straight to the pump as a simple pressure switch. But there's only one wire attached to the pressure switch. Is it grounding the relay?

[Irish_Alley]

the relay will supply power to the pump to prime it for the initial stat up for a couple seconds. then the oil pressure switch will take over once the engine starts

[Irish_Alley]

http://forum.73-87chevytrucks.com/smforum/index.php?topic=28815.msg240698#msg240698

[frotosride]

Irish I fully understand it's purpose in the system to all respects except how it does it speaking solely of how it makes a complete circuit to power the pump.
This is what I've come up with. Normal (+) 12vdc is supplied from the dual tank switch and the relay provides a ground. On key on the pump primes for 2 seconds by way of the relay receiving ground from the ECU. Once running the pressure switch completes the circuit by grounding the pump to the block.this is the only thing that makes sense with a single wire pressure switch and a (-) body system..anything that can show me another way would be greatly appreciated. I'm gonna fluke it ASAP just to see.

[Irish_Alley]

click the picture for the manual if you need to

[Irish_Alley]

this is the oil pressure switch that is for the fuel pump
it is isolated from ground and is like an oil pressure controlled toggle switch; one terminal "in" and the other terminal "out."
the single terminal ones are for the gauges and light.

[frotosride]

Thank you very much! It makes more sense that way. Glad you picked up on me mixing up the sensor with the switch. Also if I'm not mistaken the one on the lab is in the same location.  I may be wrong with that but either way I'm likely going to run both from the same area. Once again thanks.
Temps here are getting and staying in double digits so more progress will come soon.

[Irish_Alley]

no problem, it took me a couple post for it to hit me as to why you mentioned the switch only having one post.

[frotosride]

Yeah and neither of them screw directly into the block. They both have an adapter. It's funny now that I'm asking these questions I remember explaining them to someone else. What gives. Guess my grey hair just hasn't arrived.everything else in here from joint pain to memory loss!

[frotosride]

 Harness is ready now I stripped the engine down by removing the FED system. I color coded the bolts and took pics so I don't mix them up.



I planned on pulling the trigger and start pulling the 350 TBI  and make the bike my DR but this happens last night.
hopefully it will clear up and spring will take effect up here soon.

[frotosride]

Harness question? I am trying to figure out if I need the engine run wire from the alternator and if so then what do I do with it. anyone out there have anything for me?