What controls the fuel pump primer on a Delco

[Charlescrown]

My car a VR V8 has developed a starting problem. When I turn the key on I can't hear the pump priming up. I start cranking but it takes some time to start. I tried another eprom just to see if it was something in 11P program I m using but it's the same so my question is what controls the priming? Is it the ECU or the program?

[HQ355]

Have you checked fuel pump relay ? I think the oil pressure switch overrides the relay once it builds up pressure and tells fuel pump to switch on hence why it takes cranking to start.

[Jayme]

Yeah it happens. The ign being turned on should activate the fuel pump relay but if you have a wiring issue or memcal stuffed the relay for fuel pump is dual pole. If deactivated the fuel pump is directly activated by the oil pressure switch providing power. If ecm activates the relay it connects fuel pump to batt.

Its likely that you wind and wind till it builds oil pressure then bam fuel pump turns on and engine starts

[Charlescrown]

Thanks. Checked it all out and found some poor electrical connections in the relay socket. All working fine now. I didn't know the V8 had the same oil pressure switch circuit as the 6 cylinder.

[OZ38]

My VS V6 does something similar. It seems to be linked to the key fob imobiliser. If the car is locked & I press the unlock button on the key pad, then pop the key straight into the ignition & turn to reds the fuel pump will prime, further turning the key & she starts up. If I unlock the car & take my time getting in & putting the key into the ignition then turning the key to reds doesn't prime the fuel pump & further turning the key does not start or crank over. I then have to turn the key off, push the unlock button once again on the key fob, but turning to reds does not prime the fuel pump. Instead it will crank over for a short time till it fires.

If I leave the keys in the ignition after stopping the car, & then later turn to reds the fuel pump will prime & car cranks & fires straight away.

We have grown to an understanding now my VS & I lol.

Cheers

Deek

[vlad01]

Thats what a VP does as standard but it beeps to let you know you need to press the button to enable the ECU. Factory mongoose immobilizer as standard.

I wonder if your VS might have an immobilizer?

[OZ38]

Thats what a VP does as standard but it beeps to let you know you need to press the button to enable the ECU. Factory mongoose immobilizer as standard.

I wonder if your VS might have an immobilizer?

I only know it seemed very standard when I got it as an Ex-Hoonadore. So I thought the VS key fob & the little red flashing LED below the stereo was something to do with security / immobilizer ?

Cheers

[VK_3800]

That's what happens when the contact ring around the ignition key barrel moves and the key no longer makes contact - you have to rely on the buttons to disarm the VATS or wait for the timeout. Often fixing it is as simple as rotating the contacts back to the correct position.

[Charlescrown]

Ages ago I found both keys had dry solder joints. Fixed that and just lately this problem started and It's great now after pulling out and plugging back in the fuel pump relay and fuse. The terminals looked very dull in colour.

[vlad01]

Thats what a VP does as standard but it beeps to let you know you need to press the button to enable the ECU. Factory mongoose immobilizer as standard.

I wonder if your VS might have an immobilizer?

I only know it seemed very standard when I got it as an Ex-Hoonadore. So I thought the VS key fob & the little red flashing LED below the stereo was something to do with security / immobilizer ?

Cheers

the flashing red light is for the immobilizer but pretty sure the BCM takes care of that function from VR onward.

Does it have an override key in the left door pillar?

In VP they had a dedicated factory immobilizer supplied by mongoose and if the doors were unlocked and left for 30 sec or there about the immobilizer activates again and if you switch the ignition on the dash beeps with the light "press remote" flashing on the cluster.


Fuck its so funny when I see anyone else try to start my car, most take like 10 min to figure out whats going on. One guy at the valet parking couldn't open the door, was trying to use the key instead of the central locking and trapped him self even more with the dead lock function locking the car more than it was to begin with lolol