New electric fuel pump install

[nola mike]

I'm installing an electric fuel pump on my new '01 4.3L block. Getting a bit confused.

Plumbing:
1. I know I can use A1 fuel line after the pump to the carb. The pump uses 1/4" NPT fittings on both sides, and the carb uses a 3/8" inverted flare. Hopefully that's something I can get locally. I need to find a place to mount the pump. In a perfect world I'll be able to use the line from the 2bbl carb and mechanical fuel pump, and mount in a similar location. I don't have the '89 4.3L with me atm to look at...
2. What size fuel line? 3/8"?
3. Do I need a filter after the pump? I have a fuel/water separator before it. Edelbrock recommends a post pump filter, but it doesn't look like any of the V6 carbs even have the inlet filter (unless I'm missing it?)

Wiring:
I'm using achris diagram from this thread as my reference, as well as a few of Rick Stephens posts. The starter wiring on the v6 is different than on my 470, so not familiar with it yet. Also, that diagram looks like for a 2 terminal pressure switch? Mine is 3 terminal.

1. the plan is to go from coil (+) --> new electric choke --> oil pressure switch. Not sure about terminal 2 on the switch. Looks like it could either come from the yellow/red off the slave or the purple/yellow off the starter (that's the "I" terminal, right? Not sure why that exists in a TB IV ignition, I thought it always gets 12v).
2. Other side of OP switch triggers relay
3. Main relay power from red/purple off the slave
4. Other side of relay to pump.

I don't see a 90A fuse anywhere on the starter. Old one is at home so I'll check, but otherwise that should just attach between the red/purple and main starter terminal, right?
Lastly, does anyone have a pdf of the manual for the '89 4.3L? I only have the newer one, and can't access it on boatinfo. I'd like to look at the wiring diagrams...

 

[Rick Stephens]

I rebuilt the electrical harness on the V6 while it was sitting on the engine stand. Made it really easy to route wires and make clean looms. I used the OEM mounting bracket and put the Airtex pump on the front of the starboard head using the OEM mounting hardware (parts numbers: 861319,32620,32834,988231,817491,13467). I did not have the OEM water separator so I then just rubber hosed to a separator mounted on a custom bracket up the stringer. I can't remember of the lines are 5/16 or 3/8... I'll look later on.

I used the 8M0045998 fuel line from the Airtex to the 1409 carb as that is stainless and prebent to fit.

 

[nola mike]

I think I'm going to be able to get my old hard line to work and mount the pump at the front of the block. Might need a couple of fittings. How about the electrical?

 

[nola mike]

Eh, crap. I'm pretty sure I left the hard line at lowe's when I was trying to find fittings. I can't think of anything that's gone right with this damn swap so far.

 

[Scott Danforth]

try Napa for SAE inverted flare fittings for your hard line (because it is only used in Automotive and marine applications)

regarding the relay

pin 30 to the B terminal on the starter
pin 87 split to the I/R terminal on the starter and the fuel pump (this way you get priming during cranking)
pin 86 to the oil pressure switch
pin 85 to the purple ignition wire (either coil or the choke)

I went one step further, my OPS has both a NO and NC contacts. I used the NC side to ground the coil. no oil pressure, no fuel or spark. first start up after oil change requires a bit more cranking to get it to fire, however I will never have a dry start.

 

[nola mike]

try Napa for SAE inverted flare fittings for your hard line (because it is only used in Automotive and marine applications)

regarding the relay

pin 30 to the B terminal on the starter
pin 87 split to the I/R terminal on the starter and the fuel pump (this way you get priming during cranking)
pin 86 to the oil pressure switch
pin 85 to the purple ignition wire (either coil or the choke)

I went one step further, my OPS has both a NO and NC contacts. I used the NC side to ground the coil. no oil pressure, no fuel or spark. first start up after oil change requires a bit more cranking to get it to fire, however I will never have a dry start.

OK, I think I'm doing it a bit different. My OPS is also 3 terminals, with 1 NC and 1 NO. Tell me if this would work, just because it makes more sense in my head:

pin 30 to red/purple off slave (this way I have a fused wire)
Pin 87 to fuel pump
Pin 85 to common terminal of OPS
Purple ignition to NO OPS terminal
Purple/yellow (I terminal?) on starter to NC terminal on OPS (for prime, keeps me from splitting a wire)
Pin 86 ground

So during cranking I get 12v from I terminal to OPS to pin 85 triggering relay 30/87
During operation I get purple ignition to OPS, oil pressure closes switch, 12v to pin 85.
Is that correct?
Also, found my hard fuel line. Yay. Now I think I just need an adapter from the female 1/4" NPT on the pump to whatever female fitting (3/8 npt?) is on the other end of the hard line.

 

[Scott Danforth]

dont run power thru the OP switch. if it fails, you end up with a fire as they tend to short to ground when they fail

run ground to the OP switch

 

[nola mike]

Makes sense, but my purple is fused. More importantly, if it shorts to ground the way you're describing then I'd run the same fire risk since it would still be getting power through the relay, no (85-->86)?