Leaky fuel tank causing start up issues?
 

I went with a cheapy aluminum 15gal fuel cells from eBay that come with a sender.

my car is a 67 chevelle, 5.3 swap with a turbo. My fuel setup is as follows:

-10an off the tank to a pre filter.
-Pre-filter goes right into the 380lph aem pump
-Off the pump is a post filter
-10an line to the engine bay to a Y that steps down to 2 8an outs which feed the fuel rails from behind.
-the passenger side fuel rail crosses over to the front of the regulator. The other side of the regulator goes right into the front of the driver side rail.
-The bottom of the fpr returns back to the tank via 6an hose.

I know my injectors aren’t leaking because they are FIC and brand new. No torn seals.

When I turn the key to on, the pump primes the system. I go to turn it over and it theory it should fire up. Well it takes a few tries. I’m thinking the fuel tank (because it’s cheap) has a poor quality seal and is causing this. The reason why is to follow

https://cimg8.ibsrv.net/gimg/ls1tech...4349af436.jpeg
https://cimg9.ibsrv.net/gimg/ls1tech...d7e1bd0a6.jpeg
https://cimg0.ibsrv.net/gimg/ls1tech...b144f8341.jpeg

What do you see for fuel pressure in PSI at the fuel rail?

Rick

58psi

I have found that if I disconnect the battery to do work on my El Camino, the PCM forgets its learned engine parameters and takes 3-4 applications of the starter to get it going. Then it's a little wonky for engine performance until it gets warmed up a little.

Do you ever disconnect your battery? Are you certain that you have 12 volts constantly applied to the PCM memory keep alive circuit?

Rick

Hey Rick,

I followed the wiring “How To” from LT1Swap.com for how to make your stock harness essentially a stand alone harness. I remember specifically bypassing the main relay for the 12v constant the pcm needs.

Is it okay that my return feeds into the top of the fuel cell? I was checking out Tanks Inc and their pump unit has a tube that runs to the bottom of the tank for the return.

But there are two power inputs to most of these PCM's. 1 - 12 volts constant input on a wire to the PCM as memory "keep alive" power. And 2 - on a different PCM wire input, 12 volts that is only on with the ignition key in the start and run positions. This power input is what actually boots up and operates the PCM.

Are you certain that you have power to both places on your PCM? What model of PCM are you running?

Rick

its the factory pcm from with a red and blue connector. From a 02 Escalade. 12200411 is the pcm.





blue connector pin #19 says ignition supply. This is a pink wire and is energized when the ignition is on.





blue connector pin #20 says pcm battery supply. This is an orange wire and is wired directly to the battery.

A leaky tank won't prevent a start...…………..Until all the fuel leaks out.
You have other issues. As mentioned, wiring.
The return spraying into the top of the tank is not good. Aerates the fuel.