Timmie

I got a firebird 3.1 v6 that has a fuel issue.
this summer. I started the car and after a couple of minutes it started to surge, it had trouble to stay running, and after a a while it just died.
couldnt start the car anymore. it got spark, and if you spray carb cleaner in the intake it tries to run on it.

so i started to test things.

the fuel pump is working, you can hear it running.
but wheb I disconnect the fuel line, it pumps out half a glass of fuell and then nothing anymore. the pump stops running like when the line is completely under pressure. ( wich is ofcours not true since the line is disconnected )
and then nothing anymore. if you put the contact of and on again, the pump will prime again half a glass of fuel. and again thats it.


anyone got an idea what this can be ?

RBob

iTrader: (1)

At key-on, engine-off the fuel pump is only run for 2 seconds. This is done via the ECM & fuel pump relay.

There should be a test connector near the fuel pump relay. It is a single red wire and can be connected to battery + to run the pump for as long as it is connected. If you do this with the line open be very careful of sparks. Don't want a fire.

Best bet is to leave it all connected and use a fuel pressure gauge on the test port. Rear of engine between the back of the plenum and distributor.

RBob.

Gumby

Just an extra tip, while your dealing with it, wire up a back up power switch, you can feed the pump 12v direct with no side effects, just do not use a lighted switch. the internal ground used in those to light the switch, will blow the pump fuse and it won't come on automaticly. But any time you need to, you can run the pump.

Firebird90

iTrader: (1)

Mine had the same problem. Its was fuel injectors. Had 4 of them tested under 12 ohms.
Runs fine now.

Timmie

mine all tested around 12 ohms, but still need to check fuelpressure etc.
will look into it