1G Fuel pump issue.

[mitsuowner1991]

When i put the key into the ignition the fuel pump dosnt turn on and prime the engine.. soo i replaced the relay near the fuel pump in trunk and still nothing. But if i switcg the one wire on the relay to constant power the fuel pump works.. i dont get it.. ANY HELP WOULD BE GREAT!!

 

[pauleyman]

When i put the key into the ignition the fuel pump dosnt turn on and prime the engine.. soo i replaced the relay near the fuel pump in trunk and still nothing. But if i switcg the one wire on the relay to constant power the fuel pump works.. i dont get it.. ANY HELP WOULD BE GREAT!!

Key on doesn't fire fuel pump. That isn't how it works. Engine must be turning.

 

[ThunderChild]

IIRC on 1g's the signal for turning on the fuel pump comes from the MAF, don't recall if during start position it has a priming cycle.
And I believe 2g's have a priming circuit during ignition.

 

[mitsuowner1991]

IIRC on 1g's the signal for turning on the fuel pump comes from the MAF, don't recall if during start position it has a priming cycle.
And I believe 2g's have a priming circuit during ignition.

It wont start other wise and it then gets no pressure at the rail

An if i move the wire so the fuel pump is constantly on i get pressure at the rail and it starts right up. But i can't leave it like that because when I take the key out the fuel pump will continue and run

 

[1990TSIAWDTALON]

PM sent

 

[Boomdeeze]

You have to have ECMLink to be able to have the fuel pump prime or else it gets the signal from the CAS when you turn the key.

 

[mitsuowner1991]

Cas?

 

[Mello]

Cam Angle Sensor

 

[mitsuowner1991]

So you think the CAS is why the fuel pump isnt priming .. i could have sworn. It used to prime.. but then i have a 1 click when i try and start the car so i turn the key on, off a couple times and it will crank and run.. any idea!?? THANKS A TON!!

 

[luv2rallye]

All 1g's and 2g turbos (not 2gNT) require the engine to be turning for the fuel pump to be activated - just turning the key to on doesn't do it. There are other relays that activate when you just turn the key to "ON" position however which is the click you hear. Fuel system pressure is normally there for weeks so it can start immediately.

1g fuel pump activation explanation: https://www.dsmtuners.com/threads/fuel-problem-car-wont-start-need-help-asap.370110/#post-152222760

 

[mitsuowner1991]

I was just reading in the HAINES book for the 1g .. and it says on Chapter 4 section 1. " the fuel pump will operate as long as the engine is cranking or running and the esm is receiving ignition reference Pulses from the electronic ignition system"...

I really wish someone like you guys were anybody that is really good with cars and lived in New Jersey could come and take a look at it. Cuz I know it sounds so stupid and I can't figure it out. And to tow it to a shop and then have them diagnose it will add up quick as usual