LT1 Fuel System
 

I believe I posted an earlier tech question about my car having a poor start up, and also asking about an inacurate fuel guage. Well I did alittle testing, and I came to the conclusion that my poor start up is not due to bad spark (partial problem) but if I do not let my fuel pump prime (when it stops making noise) my car will not start. When It fails to start and I wait then try again, it will start. My dad even said the pump sort of sounded "weak" So when I get in my car, I turn the key to the on position, listed for the pump to prime and when its done, I turn the key and it starts right up!

My gas guage has been really off to the point where it is no longer functional (will read F when its really an empty tank). Its scheduled to be replace at TTP when I get some other work done to it, but Im thinking, is the Fuel Pump & Fuel Guage Sending relay connected and could one be causing problems for the other? Should they be replaced at the same time in normal maitnance? And whats a more performance oriented replacement I could do?

if it has to prime all teh way before the car will start the check valve that is supposed to stop fuel from draining back through the pump is prolly toasted.
not a big deal in your situation. they will likely find that the gauge problem is with the sending unit and have the tank down to service that anyway, just plop in a new pump while the tank is down and all will be happy with the world :)

later
tim

Stock GM replacement will be fine?

Or can I have one of those really loud ones :lol:

if you are planning to do any major power upgrades you may as well throw in a bigger one. a walbro 255lph is always nice to have incase you decide to add 150-200 more hp :D

later
tim

racetronix makes a plug and play pump and harness...i think theyre still a supporter at cz28, check em out

Pump is a bit of a PITA to change, you have to remove the exhaust and rear to get the tank out ( or cut a hole in the floor/hump behind the rear seat ) So their is going to be allot of labor cost.

I use the racetronix system and it is first rate, the pump will handle 550HP and comes with a new harness that runs the pump right off the alternator. The old pump is contained is a plastic housing that must be cut apart and dremeled out to make room for the bigger pump, then glued back together. The instruction from Racetronix are very clear and easy to follow.

The pump and fuel level unit are housed on one mounting bracket/bucket in the tank that needs to be removed to change the pump. I'd but a new sender and float and have them replaced.

john

Definately get the pump changed soon. 4th Gen pumps are notorious for going bad, especially if you regularly run your car below a 1/4 tank of fuel. I have the Racetronix pump. No problems at all and it is very quiet to boot. Very easy installation, it is all pre-fabbed (unlike the standard Walbro). Plus it is red, which makes it better! :P