Tyler Twerdun

Forgive me, I am very bad with electronics and relays. I added a walbro 525 pump, and have just installed a relay into the stock harness to bypass all the voltage issues. The pump kit and the relay kit are both the IRP kit. While that was straight forward enough what my question is, do these cars not prime the fuel pump with key on ignition?

When I turn my key on, the pump starts but maybe builds 20 psi of fuel pressure and stops. I took my fuel line off to see what it was doing and it pushes maybe a half cup of fuel out and stops. I dont have my injectors repined so its not ready to crank over and start, but I am reading about fuel pump resistors and such that has my head spinning.

I know the relay is working the same way as the stock harness, I am confident its all wired up right. I can even feel the relay switch on for a second, I am just curious how the fuel system typically behaves before I start buttoning up the rest of the car.

cr-rex

iTrader: (114)

Key on, it will prime full pressure everytime

did you re use that o ring plastic hat thing between the pump and hanger or did you switch to a peice of SUBMERSIBLE fuel hose

Tyler Twerdun

I drilled the old line out of the hat and installed a bulk head fitting with Teflon O washers and -8an fittings and submersible hose

Tyler Twerdun

Maybe I should mention I still have my upper intake off and a couple grounds, so maybe I have a ground up front that is causing all of this

DaleClark

iTrader: (55)

Normally key on you just get a short few second prime. Cr-rex, you must have yours wired differently from stock.

You should be able to go into the diagnostics port under the hood and connect a jumper wire from F/P to GND. With that connected, turn the key to On and the fuel pump will run full speed until you key off.

I recommend doing this after an engine install or after working on something regarding the fuel system to test for leaks. A short test is an easy and quick way to find leaks and a fuel leak can easily lead to a catastrophic fire.

Dale

Tyler Twerdun

This is what I am trying to do, in addition to running fuel through the new lines to remove any material so it doesnt get into the injectors even though I used compressed air to clean out the lines.

I'll give this a shot today.

cr-rex

iTrader: (114)

I just did the standard rewire like everyone else. Key on, it primes full pressure. It doesnt stay running, it's on for maybe 2 or 3 seconds then shuts off. It's just in that time it reaches full pressure.

Tyler Twerdun

So we figured it out, the sending unit was shorting out somewhere, with the key on and the ground on the fuel pump hat nothing would work.

when we pulled the ground off the hat, the pump would spit out a little fuel. So we pulled the hat out of the tank and tested for voltage and the sending unit was shorting the entire pump assemble out.

Disconnected the sending unit, boom full voltage at the pump.

I will probably try to located a new sending unit, id like to know how much fuel I have lol.

I actually got the car started. its a miracle, no leaks, no fires, pretty happy about it considering I tore the entire car apart except the block and ive never seen a rotary up until last November. Its idling rich but I only have the injectors scaled in PowerFC commander, and the fuel pressure its 41 psi, I think I need to lower it to 36? have to look into that more.