STRANGE fuel issues....

[Keith]

Originally Posted by camcojb

Keith,

You might also try removing the inlet filter if it's easy to do. Any restriction like that can cause cavitation at the pump and would not show up immediately, but after running and heating for a while. If that cures it replace the filter with one with a much coarser filter and use the fine filter for the pressure side. You do not want any restriction on the inlet side of the system.

Jody

Hey Jody-
We had the filter removed before in a troubleshooting teardown and it was the same problem with or without it. We're going to beat this!!

[camcojb]

Okay, how about monitoring the voltage at the pump; see if the voltage is dropping, an electric fan kicking on, etc. Voltage has a direct affect on the pump speed and pressure. If it's staying steady I'd be looking very hard at the pump and/or inlet line size to the pump.

Don't give up!

Jody

[Keith]

Originally Posted by camcojb

Okay, how about monitoring the voltage at the pump; see if the voltage is dropping, an electric fan kicking on, etc. Voltage has a direct affect on the pump speed and pressure. If it's staying steady I'd be looking very hard at the pump and/or inlet line size to the pump.

Don't give up!

Jody

Hmmm....interesting. Everything is relayed and wired right. When we checked voltage @ the pump, it dipped when the 50Amp draw on the fans kicked in but climbed right back to, I believe, 13.8V and stayed there. We also just replaced the alt with a 90 Amp version..... I still believe, now more than ever, that our issue is localized in the tank somewhere. I believe the gas can bypass will prove me right but won't know until we do it tommorow.
Also, we decided to take the car to the track out here for ****s and giggles a week ago even with the fuel issue it was having. Figured we could let it cool down enough to get a pass out of it. Well, two cars back in the staging lanes right before the burnout box, a rubber fuel line (pre stainless and -6an) exploded before the regulator and puked fuel over the entire motor. Unknow to the driver, the car started to stumble and thinking it was the car bogging, he gave it a little pedal to bring the idle up and the carb backfired and...well, you can guess what happened. We got it out before it destroted everything but it was pretty humbling which prompted the entire fuel system and engine bay/wiring makeover. Imagine how surprised we were when after firing it up and setting total timing, the car did the same fuel pressure drop as it did before......if I was going to give up on the car, it would have been last week when I told my friend to push it off a cliff and call it a day.

[lil427z]

Keith, check the voltage at the pump with a volt meter keep the volt meter hooked up from the time you start it till the time it starts acting up and see if the voltage is the same. It sounds to like to me the pump is getting over heated and shutting down.


thanks
rick kirkindall

[Keith]

Originally Posted by lil427z

Keith, check the voltage at the pump with a volt meter keep the volt meter hooked up from the time you start it till the time it starts acting up and see if the voltage is the same. It sounds to like to me the pump is getting over heated and shutting down.


thanks
rick kirkindall

Thanks...will definitely double check it although i pretty sure we did it once before. Since i first posted this we haven't really touched the car...just sitting collecting dust while I work on other projects. We'll get back to it and i'll report to everyone with pics. Right now I'm chasing an electrical demon in a 67 Camaro conv. which is chapping my ass too. It's got a slow draw somewhere and if the car sits for more than 3days without being started, the batt. is dead. Can you believe I actually enjoy this crap?