305 TBI stock setup, been running through this car trying to piece it back together. Recently installed a fuel pressure gage to verify fuel pressure and was able to get around 10psi but in the interim of adjusting timing and idle etc. the car ran out of gas. I elected to replace the fuel pump with a TPI pump because I do not know how old the pump is in the car and just wanted to do preventive maintenance at this point. I also replaced the fuel filter along with the coil. The previous owner cut an access hole, albeit a crappy one, but it makes changing the pump quicker. Anyway, prior to running out of gas and changing the pump, the car primed and delivered fuel with no issue. Now that I have replaced the pump with a new unit, I have no power to the pump. I have confirmed that i have 12v reference at the relay on the orange wire, but the power wire that goes to the pump is only getting 4-6 volts (at the relay) with key on. I doubled checked the wires at the pump and the bulk head connector and all seem as they were before. Do not see any breaks or damage to wires. I checked the 20a fuse by the battery and that fuse is good, also checked all the fuses under the dash and all are good. What am I missing, I feel like it has to be something simple. Battery voltage is good as well. I can crank the car but obviously there is no fuel up at the TBI.

 

Have you checked the ground for the fuel pump? Some are under the drivers side rear seat and some (like mine) is just in front of the drivers side front seat just under the carpet and just past the sill plate. Sometimes this gets corroded and with the high resistance drops the voltage. Also, check the engine to firewall braided ground strap.

 

Will do. I checked the ground wire at the bulk head and that’s good. Didn’t realize there was another ground for the fuel pump.

 

I have not gotten back to checking the fuel pump issue just yet, but after researching other items of interest I have determined I do not have all the required engine grounds. I ordered new ones and will install the needed grounds and then go back to troubleshooting the fuel pump issue.

 

Well after tracing wires and determining where I lose voltage, I was able to figure out the issue. This might be a new one. One of, which happens to be the power wire, prongs broke off inside the connecter going to the fuel pump. I will have to replace the sending unit.

 

This that the connector that plugs into the Yellow connector on top of the fuel pump hanger/sending unit?

 

Yes, the bottom side of that yellow connector that sits in the fuel tank.

 

Is this for the car with the built LS1 and T56 powertrain or another Camaro you have?

Is the sending unit in the car a nice good unit with just the pin in the connector broke off?

 

It is for the other stock camaro I am rebuilding. The sending unit itself is in good shape, just that prong is broken.

 

OK. I was going to say that Racetronix makes a 4 pin version of that Yellow connector that goes from inside the gas tank to the outside of the gas tank. That would allow you to run two power wires into the gas tank to the pump and let you move the ground wire from the 3 pin body connector and use and external grounding lug.

If this just going to be a regular TBI car then no need for that then.

FS Bulkhead Connector Assembly 4-way (BCA-4W): Bulkhead Connectors | Racetronix

Universal Bulkhead Wiring System, 4-Way (BCWS-001): Pump Bulkhead Wiring Systems | Racetronix

I'm not saying to buy these. Just letting you know they exist.

I'll see if I can find just the 3 pin version of this.

 

Ok cool, thank you. I didn’t know they were out there but I didn’t rewlly
look too hard honestly.

 

So a new Yellow sending unit bulkhead connector would fix you right up? It's just that pin broke off that is the only problem?

If so then it will be a lot cheaper to replace it instead of an expensive entire fuel pump hanger/sending unit.

 

I have NOT done this before.

Would this work to fix your problem.

FL98 / F7 Bulkhead Connector Assembly (BCWA-FL98HD): Pump Bulkhead Wiring Systems | Racetronix

 

Also, since I'm using that exact bulkhead connector on my sending unit is that you can't just drop it on and away you go. It doesn't sit right you'll need to get the grinder out and shave some off the side closest to the feed tube.

Then once you've done that and are happy with it when you go to install that little tab on the vapor side of the sending unit find a 10mm deep socket and give it the sauce. You only one chance to get it right, you can't buy those little tabs you have to buy the entire bulkhead connector

I've had a spare bulkhead connector for the longest time as a Justin case

 

Thank you everyone for the info. It would seem I can buy the new wiring kit with fitting for 50$ plus shipping and have to slightly modify or I can get an entire new sending unit with the wiring for about 88$ shipped. I might as well just get the entire sending unit and have a spare unit essentially on the shelf minus the wiring.