fuel tank bulkhead connectors.

[The Dark Side of Will]

Walbro claims I am pulling around 16 amps or so at the fuel pressure I am running. I believe I have a 20 amp fuse for the pump. I was running a 10, when I first installed it, but it blew that fuse under a 5th gear pull on the highway but was fine for months before that and even Dyno time was fine with a 10 amp.

If you blew a 10 on a highway pull, then your fuel pump *circuit* is probably just a hair over 10A, so that the accumulation of heat from extended loading at that current causes the fuse to "slow blow". Even if the fuel pump would pull 16A with a full 13.8 bolts, the resistive losses in the fuel pump wiring at that current level will reduce the voltage across the pump. If you're pulling close to 15A through a 16ga wire, then you likely have pretty high resistive losses, at least for a nominal 12V circuit. If the pump wants 16A, then bumping the wire up to 14ga, or even 12ga if you're feeling extra sporting, would help.

But obviously if my voltage is not at 13 volts, then that means I am probably pulling more amps.

Regulator is supposed to hold 13.8-14.3 or so, depending on temperature... higher voltage when cold, dropping as it warms up.
As noted, the high current through small wires will reduce the voltage the fuel pump sees.

When voltage goes down amps go up right? Ohms law right?

That's not Ohm's law at all. A constant power load like an AC motor can do that. I'm sure if a DC motor does that. Motors are non-Ohmic devices anyway.

I am using all the stock wiring from the c203. So I have a 30 amp relay keyed off the ignition with a 14 gauge running to the battery terminal c500 location. The relay is behind my driver's seat, and the wire to the pump is spliced into just before the c203, where the aldl connector was at to hotwire test the pump for diagnosis.

So I am running through the c203, running through the bulkhead, going through the pump connector just inside the engine compartment, and then all the factory wiring to the pump hat, and factory wiring inside the tank itself.

Yeah, you have a bunch of the worst factory wiring still in place. If you're going to upgrade to 14ga or 12ga, you definitely want 280 pins rather than 150. Since the kit Eric posted already uses 14ga, that's a great place to start.

[Shaun41178(2)]

Since that racetronix wire harness has 4 wires instead of three like factory, I am thinking this.

1 for ground.
1 for sender.
2 for power to the pump.

Thoughts? Two 14 gauge wires running power to the pump vs a single 12 gauge.

[The Dark Side of Will]

Pump power and pump ground really really should be the same size.

In residential electrical, a 14ga wire is rated for 15A, meaning it can conduct 15a indefinitely without ever getting hot enough to damage anything. 14ga is enough, 12ga is overkill.
Also, if the +12V side is bigger than the ground, then the ground will run hot and reduce the voltage drop across the pump by incurring resistive losses between the pump ground terminal and the battery negative terminal.
I'd be more concerned about the resistance across those tiny pins.

However, I think if you use the new bulkhead connector Eric found, wire the fuel pump with 14ga and run GT or MP 280 terminals in any connectors you have to use, it'll be fine.

[Shaun41178(2)]

I am coming right off the relay, hot wired pump. I'll be installing something like this to allow servicing but that's it.

So you are saying don't use two positive wires to the pump then? I'm trying to minimize voltage loss

Screenshot_20220823-215756.png (265.76 KiB) Viewed 4188 times

[The Dark Side of Will]

I am coming right off the relay, hot wired pump. I'll be installing something like this to allow servicing but that's it.

Screenshot_20220823-215756.png

Is that a 150 or a 280?
Don't just buy shit from Advance without knowing what it is.

At least get a kit from a company that has a clue how wiring works. Here's Metri-Pack 280 parts: https://www.customconnectorkits.com/280-parts/

So you are saying don't use two positive wires to the pump then? I'm trying to minimize voltage loss

Current is the same at every point in the circuit, from the battery positive terminal, through the wiring, through the pump motor, through the ground wiring and back to the battery negative terminal. If you have 15A on the +12V side of the motor, then you also have 15A on the ground side of the motor. That current through the ground wire still causes resistive losses. IOW, the "ground" side of the pump motor could be at +0.5 to +1.0 volts if the voltage drop through the wiring is excessive when carrying 15A of current.

However, like I said before... just wire it up with a single 14ga wire on both sides, using Metri-Pack or GT 280 series connectors wherever you need to connectorize it and it'll be fine.

[ericjon262]

There's only two wires going through the Fiero bulkhead, the pump power, and the sending unit power. They are both grounded to the metal sending unit, which has a ground attached on the top of the sending unit.

[The Dark Side of Will]

There's only two wires going through the Fiero bulkhead, the pump power, and the sending unit power. They are both grounded to the metal sending unit, which has a ground attached on the top of the sending unit.

My bad, I'd forgotten that deal.

[ericjon262]

There's only two wires going through the Fiero bulkhead, the pump power, and the sending unit power. They are both grounded to the metal sending unit, which has a ground attached on the top of the sending unit.

My bad, I'd forgotten that deal.

It would appear as though Shaun did too, but thats why we're all here, to help and harass.

[The Dark Side of Will]

Just an attack, not an observation.

[The Dark Side of Will]

Since that racetronix wire harness has 4 wires instead of three like factory, I am thinking this.

1 for ground.
1 for sender.
2 for power to the pump.

Thoughts? Two 14 gauge wires running power to the pump vs a single 12 gauge.

There's only two wires going through the Fiero bulkhead, the pump power, and the sending unit power. They are both grounded to the metal sending unit, which has a ground attached on the top of the sending unit.

If there's a direct, high current, low resistance ground path through the sending unit disk, then having 2x 14ga supply wires and 1x 12ga ground wire could work.

I still maintain that a single 14ga wire with 280 series terminals in all connectors would be fine, though.

[ericjon262]

Since that racetronix wire harness has 4 wires instead of three like factory, I am thinking this.

1 for ground.
1 for sender.
2 for power to the pump.

Thoughts? Two 14 gauge wires running power to the pump vs a single 12 gauge.

There's only two wires going through the Fiero bulkhead, the pump power, and the sending unit power. They are both grounded to the metal sending unit, which has a ground attached on the top of the sending unit.

If there's a direct, high current, low resistance ground path through the sending unit disk, then having 2x 14ga supply wires and 1x 12ga ground wire could work.

I still maintain that a single 14ga wire with 280 series terminals in all connectors would be fine, though.

I agree, but the terminals in that connector are not 280, I'm not sure what they are, but they are definitely way smaller than 280.

[The Dark Side of Will]

I agree, but the terminals in that connector are not 280, I'm not sure what they are, but they are definitely way smaller than 280.

The Ballenger unit says 2.8mm terminals: https://www.bmotorsports.com/shop/produ ... ts_id/5105
https://raceworks.com.au/connectors/in- ... s/weld-on/
They look lower drama than other suppliers

[ericjon262]

I agree, but the terminals in that connector are not 280, I'm not sure what they are, but they are definitely way smaller than 280.

The Ballenger unit says 2.8mm terminals: https://www.bmotorsports.com/shop/produ ... ts_id/5105
https://raceworks.com.au/connectors/in- ... s/weld-on/
They look lower drama than other suppliers

both are the same fitting, but not the Racetronix part mentioned earlier in this thread, the racetronix is a more "drop in" solution. I have both at my house.

I won't say the ballenger/raceworks/holley part is impossible to install in the Fiero tank, but it damn sure wouldn't be easy, it's about 1/3 of the size of the whole sender top, but it has the benefit of larger terminals, and 6 pins instead of four.

[The Dark Side of Will]

I agree, but the terminals in that connector are not 280, I'm not sure what they are, but they are definitely way smaller than 280.

The Ballenger unit says 2.8mm terminals: https://www.bmotorsports.com/shop/produ ... ts_id/5105
https://raceworks.com.au/connectors/in- ... s/weld-on/
They look lower drama than other suppliers

both are the same fitting, but not the Racetronix part mentioned earlier in this thread, the racetronix is a more "drop in" solution. I have both at my house.

I won't say the ballenger/raceworks/holley part is impossible to install in the Fiero tank, but it damn sure wouldn't be easy, it's about 1/3 of the size of the whole sender top, but it has the benefit of larger terminals, and 6 pins instead of four.

In looking at the unit... It looks like it's literally just a pass-through. The harnesses on each side still need mating connectors. That's shown on the RaceTronix site, but not explicit on the Ballenger site. The offset six pin mating connector looks like the AMP part that mates to my '06 STS DBW throttle... so the whole thing may have come out of the AMP catalog and neither vendor says so.

[ericjon262]

visual reference, each came with all the parts shown.





racetronix comes with pre-wired pigtails, Ballenger comes with terminals and connectors shells/seals. the side by side gives a better visual as to how massive the Ballenger is.

The connectors attached to the ballenger are made by Aptiv, here's on on Mouser. the surface finish on the pass through is much shinier than the connectors, which leads me to believe they may be made by two different manufacturers. the only part number visible on the pass though is 80700 1-A, which I haven't been able to find a reference to.

https://www.mouser.com/ProductDetail/Ap ... VTNQ%3D%3D

[The Dark Side of Will]

Interdasting. The '06 STS throttle has an offset rows config like that, but the replacement is listed as an AMP PN in the shop manual. Maybe Aptiv made their own version because they could? Maybe they sub them to AMP?

Do I need to buy both to figure it out for my DBW throttle?

[ericjon262]

Interdasting. The '06 STS throttle has an offset rows config like that, but the replacement is listed as an AMP PN in the shop manual. Maybe Aptiv made their own version because they could? Maybe they sub them to AMP?

Do I need to buy both to figure it out for my DBW throttle?

I would go with whatever the shop manual says it requires.

[The Dark Side of Will]

Interdasting. The '06 STS throttle has an offset rows config like that, but the replacement is listed as an AMP PN in the shop manual. Maybe Aptiv made their own version because they could? Maybe they sub them to AMP?

Do I need to buy both to figure it out for my DBW throttle?

I would go with whatever the shop manual says it requires.

Yeah, of course. I'm just idly wondering if Aptiv copied AMP... Or is that an USCAR standard connector?

[ericjon262]

Since something appears to be going wrong with my fuel delivery, this is quickly becoming more important...

I like the convenience o the the Racetronix part, I like the capacity of the Ballenger part.

I took the Ballenger part and held it up to the opening of the fuel tank, to get it low enough to fit in the tunnel, the connector gets buried in the tank opening too log to be removable, so it will not work.

that leaves the Racetronix part, which uses tiny metripack 150 terminals... I could use 3 terminals for the pump, one for the sender, and ground through the sender as GM did originally, this will probably get the car back on track the fastest.

another possible option is to use a passthrough like this:

https://www.summitracing.com/parts/rhc-21-0006

I like the part alot, but there's almost no info on summit's site, or their site, and a duck duck go search turns up nothing as well. They list them as being for water tanks too, which doesn't mean they won't be ok with fuel, it just means they were meant for water...

I emailed them and asked for more specifications, for now, I think I'm going to install the Racetronix setup in my spare sender with my spare pump, and then use the tank and sender in the car to prototype something more permanent. in the meantime, once I hear back from Rhodes, I'll go ahead and pick up a connector and put it in a jar of gas to see how it does. they're cheap enough, I might get two or three for testing.

[ericjon262]

another possible option is to use a passthrough like this:

https://www.summitracing.com/parts/rhc-21-0006

I like the part alot, but there's almost no info on summit's site, or their site, and a duck duck go search turns up nothing as well. They list them as being for water tanks too, which doesn't mean they won't be ok with fuel, it just means they were meant for water...

I emailed them and asked for more specifications, for now, I think I'm going to install the Racetronix setup in my spare sender with my spare pump, and then use the tank and sender in the car to prototype something more permanent. in the meantime, once I hear back from Rhodes, I'll go ahead and pick up a connector and put it in a jar of gas to see how it does. they're cheap enough, I might get two or three for testing.

Details.

https://www.mouser.com/datasheet/2/159/ ... 514443.pdf