LS1TECH - Camaro and Firebird Forum Discussion - Fueling & Injection

Can someone hold my hand on dual pump wiring please

Mbs1994 — Sat, 16 May 2026 20:33:58 GMT

Idk if I've just over read on this and fried my brain but I cant seem to get a full grasp on this. It will be dual walbro 450s in a stock bucket, running a new return and feed, hobbs switch, blah blah blah. What's killing me is you have the harness for the stock pump and float and the harness for evap? I think is the other plug. So I keep seeing people talk about just powering it from the battery and relays which I get but what do you do about the stock plug? Take the pins out for the pump so the float still has power but then delete the plug for the original pump? Also I keep reading about racetronix harness and it seems like it's multiple pieces and not sure again where that ties into the prior mentioned float/pump plug? I think like I said I may have over whelmed myself with so many different ways it's been done. Can someone explain it like they were telling their child please 😂 it really just boils down to am I powering the float off the oem harness and then wiring power to the pumps separately via direct power, relays, and a Hobbs for the second? I'm picturing almost like wiring a amp but instead of channels its pumps, am I wrong?

Rich condition

Mbucalo — Sun, 10 May 2026 19:01:41 GMT

5.3 speed density tuned with flex fue injectors l return less rail.. back plugs...I read on a different forum about flex fuel injectors and non flex fuel harness I'm wondering if this is my problem I did have to use adapters to go from harness to injectors any help or advice would be greatly appreciated.

Racetronix 3rd Gen hotwire kit signal wire

upstateNY_Rich — Sat, 09 May 2026 15:00:39 GMT

I have a 1989 Firebird with a LS1 swap and I purchased a Racetronix hotwire kit and pump for my car that was originally fuel injected. My question is do I need to run a signal wire back to the included relay in this harness. I was thinking that i could use the original wire that went to the cars original relay. I have watched a bunch of videos and I have not seen anyone adding a signal wire. I thought this would be easier than using the relays that came with my PSI stand alone harness and wiring the pump.

94 camaro evap delete

Littlelouie69 — Thu, 07 May 2026 18:57:04 GMT

I swapped in a Holley Dominator ecu and wiring, so it will no longer control the evap system. I simply need to vent the tank to avoid excess vacuum and pressure buildup. My question is which line should I use to vent to atmosphere? I would like to have the vent line go to the charcoal canister first, and to atmosphere afterwards, so there isn't excessive fumes in the garage.
Thanks.

99-02 F Body Holley Pump Module

gjohnsonws6 — Sat, 02 May 2026 19:54:31 GMT

Anyone using one of these in their 99-02 F body?

O2 sensor offset for fuel economy ?

Full Power — Fri, 01 May 2026 20:46:41 GMT

Anyone experiment with, or have success with tweaking O2 sensor switch voltage for LEANER AFR in closed loop?
I tried a -30mV and it went richer. .. Next attempt is PLUS 30 mV
Going to shoot for 14.9 to 15 AFR in closed loop.
Power Enrich reacts pretty quick, cuts in at 115 kPa

Any chance I'll get another MILE per GALLON this way ?
My fuel tank is only 26 gallons, so one more MPG will get me 26 miles further down the road- for free-
Am I doing this right ?
.
For reference, GEN3 4.8 Liter, baby torque cam, TVS1900 blower at 11 PSI

Ford injectors on LS1

sycl956 — Thu, 30 Apr 2026 00:54:45 GMT

We Put these injectors that were marked as denso from TSP they fit good and no leaks but was told the spray pattern will cause issues as it�s for a DOHC intake I believe these injectors are from a 2012 6.2 f150 the nozzle had 6 holes while the stock ls1 look alot simpler
car runs rough and only works somewhat decent when warmed up
fuel pressure is at 58
cammed torquerv2

LS3 Swap � Fuel Rail Quick Connect Leaking (Won�t Fully Seat)

dcoutofstep — Thu, 23 Apr 2026 00:28:52 GMT

LS3-swapped 944 with ~1,500 miles.

I disconnected the fuel feed line from the rail a while back during a hydroboost install. Now I can�t get the line to reconnect without a small leak once the system is pressurized.

Setup is a standard GM quick-connect fitting:

Female connector on feed line
Male fitting on fuel rail

When I connect it, I hear/feel the retaining clip snap over the bead on the rail, so it seems like it�s locking in place.

However:

I get a small leak at the connection under pressure
The connector doesn�t feel fully seated - there�s ~1/8� of play

I�ve tried multiple configurations of the internals in the female connector. Current setup is:

Washer → black O-ring → yellow O-ring → retaining clip

Details:

Retaining clip is new
O-rings look to be in good condition
No obvious damage to the rail fitting

Feels like I�m missing something simple here.

Questions:

Am I running the correct O-ring stack/order?
Should this connection have zero play when seated?
Is there a spacer or internal piece I might be missing in the female fitting?
Could the connector itself be worn even if it looks fine?

Any guidance appreciated.

Bulkhead delete plate/seal

nossty1 — Wed, 22 Apr 2026 19:59:11 GMT

I was using a bulkhead fitting to get fuel to my large Aeromotive pump but am wanting to go back to intank(dual 525s). Does anyone know of some quality bulkhead delete setup? I'd rather not just cap the bulkhead AN fitting, but I can if it's a last resort. Thanks