Best way to purge fuel system(after long storage)

[haskett]

The fuel in my car is a year old and I don't want to gum up my new engine and newly calibrated injectors with it.

What's the best way to purge the fuel?

If I turn on the ignition with the fuel line disconnected from the fuel rail, will it spray out or will the car detect no fuel pressure and turn off the pump?

 

[TRQJUNKIE]

Unhook the fuel line there at the engine before the fuel rail and make some kind of relay for the fuel pumps so they just run till your tank is low. Then throw some new stuff in there . I don't think you will have gumming issues i may be wrong but you should be fine. Next time you let the car sit for more than 3 months I'd use some STA-BIL in the tank to keep the fuel from separating.

 

[Jimmysidecarr]

Unhook the fuel line there at the engine before the fuel rail and make some kind of relay for the fuel pumps so they just run till your tank is low. Then throw some new stuff in there . I don't think you will have gumming issues i may be wrong but you should be fine. Next time you let the car sit for more than 3 months I'd use some STA-BIL in the tank to keep the fuel from separating.

This.

You will have to provide independent power to the pumps because the PCM turns them off after a few seconds when there is a no start.

You don't need to get it all, it will dilute when you fill up with fresh.

Be very careful about sparks from your independent power source and abundant gas fumes. Have the door open and the shop fan blowing out and your extinguisher within arms reach.

 

[TRQJUNKIE]

Do you think he could just keep cycling the the pumps by turning the key on and off?

 

[Brutal Metal]

The lines probably wouldn't build up enough pressure just cycling the key on off especially with a disconnection at the rail..

 

[Black306]

There are a number of ways to do it. One is to use a custom tune that keeps the pumps running when the key is in the run position. Here is a tune that was provided to me, however, I havent tried it yet.

Index of /temp/tunes

The other works if you have a dual FPDM conversion and a few pins lying around. I have wired my pumps in series so that they each receive half the voltage. Power comes from the wire already setup from the battery to power the 2 FPDMs.

Anyone with a PPRV delete will also be able to cycle the pumps once and have a constant, albeit slow, stream of fuel come out as long as the hose is lower than the supply of fuel.

With any method, I like to disconnect the fuel line after the fuel filter and attach a 3' piece of 5/16" hose to the nipple. No need to add a clamp since there won't be any pressure to pop the hose off.

 

[SVTkel]

A good thread.

 

[haskett]

Thanks for the helpful replies. I assume the fuel pump runs on 12 volts?