blakngold4life

I posted a couple weeks ago about having the common C4 problem of fuel starvation during autocross, recently it happened with 3/4 of the fuel left. I pulled the assembly out today but didnt see anything that looked too bad. A couple wires have some bare spots but there is nothing that I see they could ground themselves too. I'm planning on replacing the wire harness as well as the sock. Here are pictures of the inside of my tank and the pump assembly, let me know if you see anything that you think should be addressed or any other ideas.

jaa1992

replace that nasty filter sock

Clean it all up, if you want to replace it racetronix has a great pump replacement kit!

bwiencek

pulsator may be leaking - I don't know a good way to bench test it out of the car but if it leaks it can cause all sorts of odd low pressure problems.

383vett

Fuel cell.

engle1147

Make sure when the new sock goes on the new pump that it is orientated correctly (long end towards the rear of the car - yours is correct in the photo). Use a couple of black zip ties (tie wraps) to secure the fuel pump's wires (power & ground) to the steel intake tube....this will keep the sloshing fuel from wiggling the new wires/connector as much on the old harness (probably why you had insulation bare spots).

pmihaltian

That's interesting; I never knew that there was a proper position orientation for the sock. What happens if it’s supposedly positioned incorrectly?

engle1147

If the sock doesn't make as good of contact with the bottom of the tank/tray (where the fuel should be - gravity and all that kind of stuff) when the level is low or when there is a significant amount of "slosh" the pump would be more likely to suck "air" instead of fuel.

PS: Skip testing/installing pulsator and just install a short length of high pressure fuel injection hose there instead. Most aftermarket fuel pump kits some with a short length of hose for this purpose.

blakngold4life

I installed the new sock and addressed some wires that were a little loose, ordered a new harness but that wont be here till next week so I just put wire clamps on them to get rid of the bare spots for the time being. When removing the pump we noticed that some of the bolts were broken, and didnt think much about it. Got home from filling the car up with gas and saw that the part that bolts to the pump assembly to the fuel tank was leaking under pressure. Any ideas how to get broken/stripped bolts out of the fuel tank aside from drilling?

engle1147

I doubt the bolts themselves are stripped - usually the threads strip out on the tank first

For the ones that are stuck use some needle nose "vise grips" to grab the bolt heads - once "locked on" pull up while twisting counter clockwise.

Use caution when working on semi - open fuel cells

joeld

I guess I'm missing something here. I've seen this tip on other posts about using the zip ties to hold the wires secure. How do the plastice ties not melt from the gas?
I'm changing my pump in a few days so that's why I'm asking.

Thanks
Joel

engle1147

The ones I used a few years back are still holding. I still have a bag of the tie wraps I used - they are made by a company called Commercial Electric. The part number is 776 301 these ties are pretty thick plastic and use an internal "metal" tab to hold/latch them in place. I don't remember where I bought them though.

Test if you don't trust it:
Put some gas in a jar - insert a tie wrap into jar filled with gas - cap off the jar....wait to see what happens.