Explorer OBD2 Harness Re-work

[DirtDonk]

Seems like the later Explorer would be a nice upgrade. Higher pressure isn't necessarily anything to be afraid of, as you're needing to build a stout and tight fuel system even for 45 psi. So the better efficiency potential would seem to be worth it.
Even the standard replacement pumps like we sell in the Sherman are good for 90 psi and are just held down by the pressure regulator.

Is the later Explorer pump "special" regarding it's ability to throttle down when necessary? Or is it just a standard pump with the computer doing it's thing?

Paul

 

[Boss Hugg]

The only thing about the explorer pump is it has the regulator built on the assembly. The computer simply grounds the relay that feeds power to the pump.


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[Viperwolf1]

The pressure regulation is done in the tank and the higher psi makes a 17lbs injector perform like a 19lbs.

Actually it makes them flow more like 23 lb injectors at 40 psi.

 

[broncoman1972]

Is the later Explorer pump "special" regarding it's ability to throttle down when necessary? Or is it just a standard pump with the computer doing it's thing?

Paul

Here's a pic of the explorer returnless pump off its bracket when I modified it for my build. You can see the regulator and the tube it dumps fuel from into the tank.


Sent on the fly

 

[DirtDonk]

Interesting for sure. Thanks for the pic.
I wonder why they need to vary the pump flow with the computer then, when there is a physical regulator right there to do the same thing?

Looks like the pump itself is at least similar in shape, if not internal design.

Thanks for the pic.

Paul

 

[Boss Hugg]

The computer doesn't vary the flow. It just turns the pump on.


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[broncoman1972]

The computer doesn't vary the flow. It just turns the pump on.


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^^What he said.

Sent on the fly

 

[DirtDonk]

Ok, thanks. Then all this previous talk of the computer regulating the flow is really just the new pump assembly has it's own internal bypass regulator, to not only regulate pressure but to act as the return line.
Just like all the aftermarket setups we see now like the Fuel Command Center from FiTech and the ones from Edelbrock and the others. But likely better at doing it because it stays cooler in the main tank.

Paul

 

[EFI Guy]

Correct. The 99-01 system is referred to as "mechanical returnless". I guess that's sort of a myth considering it was returned just before it left the tank. You can run an external fuel pressure regulator and return line on a 99-01 system. It just needs to be fed a constant 65 PSI, so no vacuum reference.

Later returnless systems control the fuel pump to regulate flow, some even have dual pumps.

 

[SpareParts]

Received another harness to install yesterday... Gary, as usual does a great job putting these together!

 

[Tiko433]

Christmas in March ! Nice ceramic Sanderson's I see too.

 

[SpareParts]

Christmas in March ! Nice ceramic Sanderson's I see too.

Yep, I'm sure he will be pleased with it when I'm done.

 

[luke]

efi guy. i am ready to purchase one of you harnesses and pcm. i sent you a pm, but i think my box was full if thats possible. anyways i am deleting some of my old ones if you want to try. thanks!

 

[JoshT]

Thanks to the PB debacle, all photos from post 2 are gone. Any chance that this can be fixed, or that someone might have them saved and could send me a copy?

I bookmarked the thread two years ago when I first found this, but never thought about the possibility of the pictures being held hostage. If I'd expected that I'd have saved an offline copy of the thread.

 

[EFI Guy]

Thanks to the PB debacle, all photos from post 2 are gone. Any chance that this can be fixed, or that someone might have them saved and could send me a copy?

I bookmarked the thread two years ago when I first found this, but never thought about the possibility of the pictures being held hostage. If I'd expected that I'd have saved an offline copy of the thread.

Fixt!;D

.

 

[JoshT]

Thanks!

Really wish I could just send in the harness and have you work it. It's going into a Ranger instead of an EB. I know that it will need to be extended, because I don't have room to stick the ECU in the firewall like y'all do. I've got the Escape holder and a small metal ammo can that I am going to try to make into an under hood ECU box. Unfortunately the cab isn't currently mounted to the frame, I don't know where it'll end up or how much extension I'll need. Can't very well hire you to do it if I don't know what I need you to do.

If I get to the point of reinstalling the cab and haven't got the harness done yet, I may be in touch. With the hottest part of summer on the way, hopefully I'll be able to get it done first. At least with the harness I can bring it inside to work on, no SO to answer to.

 

[73azbronco]

First few posts you mention removing a 33 wire i think which goes to tranny. Would you want that wire if you were going to say use a 6r80?

 

[EFI Guy]

My understanding of pin 33 (of the C115, not the PCM) is that it sends a ground signal in neutral only to the GEM module. The purpose of the signal in neutral only is to allow the transfer case to shift into low range when in neutral. Since all the 5.0's were AWD or 2WD it makes it even more pointless. I remove it so that it doesn't get confused with the coolant temp wire which is the same color and also passes through the c115, and also one of the o2 wires is the same color and connects to the transmission harness.

 

[Twister02]

Gonna bump this thread. I am swapping a 1999 Ex 5.0 into my 1985 Bronco II, and have run across your videos and it looks like something i think i can tackle. Doing research, what are people doing for the fuel systems?

 

[bronconut73]

Welcome to CB Twister.

EFI guy is the absolute best at this stuff.

Good luck with your project Sir.