Evo X upgrades

[asshanson]

Oh nice, didn't even think of that until after I wrote the post.

[scheides]

Ok that is my big beef with the aeromotive pump, why on earth would they wire it backwards from the product they are directly trying to compete against? Makes ZERO sense!

Glad you figured it out, that is just nuts!

[mlomker]

The polarity fix got the pump working, of course. The problem is that it has too much flow for the return on the stock hanger and is pressuring the surge tank to ~6psi. This causes it to spring a leak at the 044 pump connection. :(

I think I've seen forum posts about ways to make the return less restrictive. Otherwise I'll need to downgrade that pump to a 255.

[goodhart]

Would it be easier to swap in a larger return line? like -6 or -8 or something? What size is it now? Then you could have the extra flow you may need down the road, AND have it not overflow. Either way, glad to hear ya got it working!

[mlomker]

Would it be easier to swap in a larger return line? like -6 or -8 or something?

The line isn't the restriction, it is within the stock hanger. They have a restrictor that creates the venturi effect used to pull fuel over from the other saddle in the tank. It was designed with stock flow in mind. Some people drill it out a bit but it's a little risky because if you drill it out too far then it stops drawing from the other saddle and you run out of gas with the gauge reading 1/4 tank.

[Kracka]

Sell and replace with stock, 255, or DW300?

LMK if you need a stock pump.

[mlomker]

Sell and replace with stock, 255, or DW300?

We will see. I have a pair of 255 in the Full Blown hanger so I could pull one to test with.

Discussion about increasing the return capacity:
http://www.evoxforums.com/forums/showthread.php?t=28036

[mlomker]

It looks like air in the fuel lines is my problem. I purged the surge tank/return and now that's all happy. I snugged up the surge tank fittings so no more leak.

Right now I'm getting no fuel pressure to the rail so I suppose there's air in that line as well. I ran out of lunch hour so I'll have to decide what to do with that later.

[asshanson]

Air in the feed line shouldn't matter, if your pump is running it should push those air bubbles out.

[mlomker]

Spend quite a few hours experimenting. It certainly appears that the return line for the stock in-tank hanger is too restrictive. I just swapped a regular 255 into the hanger and will give it a try in the morning. The car seems to run fine if I leave the in-tank pump unplugged but everything I tried with it running would result in fuel pressure going to 0 at the motor. I even swapped in the Bosch instead of the Jays 044 and the symptoms were identical.

I hope the 255 works. If not then I'll probably try cutting off the return hose in the hanger to bypass the restrictive return/siphon. Too many people eyeballing my car...leaving it parked in one spot for too long is making me nervous. I need to move that car tomorrow...even if that means running off the surge tank and stopping half-way home to refill it.