Fuel pump problems?

[67Fox]

I have a problem starting the car. (I know it's a common problem, and have read a lot on hear about it but....)
So i have not run the car for a few months. (been away for work etc...)

I was free this weekend so i thought I would change the spark plugs clean the stepper motor and take her for a spin.
So I changed the spark plugs (what a pain in the arse job that is!!! but that's another story )
Cleaned the stepper motor but that was really clean, so easy job. ( the stepper motor was very lose in the plenum though, two fingers and it was lose!)
Checked the spark plug leads were correctly placed on the correct spark plugs, Twice!!

So here goes. Started the car , OK.........15 sec or so later the car stops running. So I try to start her again and the engine turns over and over but does not catch.

So I check again the spark plug leads making sure all where correctly on the spark plugs, try again nothing. So I removed the 8x extenders and tried again. Nothing
So then sat in the car and just turned the ignition key until the ignition was on. (Red light) And listened. nothing! no humm from the petrol pump?? Is this normal?
When turning the key and waiting 3s or so secs I hear a click. but no humm. Is this normal?
I can't remember when the car ran fine if the petrol pump primed before I started her last time. Typical, i don't remember this.

I did jack the car up and gently tapped the pump to see if that was it but nothing.

I know it could be the immobolisor, but I believe that this has been bypassed by the previuos owner. As the car has started before with the car locked!!
I have also tried to lock /unlock / lock / unlock /... but also nothing

Any suggestions would be welcome.

[67Fox]

QBee said:

You always hear the fuel pump priming. No pump prime, no run.
I have also noticed recently that I can hear the fuel pump when stopped at traffic lights.

Immobiliser is the normal reason for no pump prime.
Lead off the pump is another possible.
Stuck relay.
No fuel in tank.
Inertia switch......but you have to jolt the car pretty hard to activate that in my experience (once in 30,000 miles, entering a gravel trap sideways.)

Of course it won't start without a spark either.....king lead, ignition amplifier,

OK QBee.
Were would I find the (maybe stuck) Fuel pump relay please. Foot well? and if so which colour?
Fuel is in the tank as I filled it up not long ago.
Inertia switch, possible..... Were would I find that little gem then?

[67Fox]

davep said:

From the diagram: +12Vdc battery voltage (N) is applied to the Fuel Pump Relay (COM pin 30), the Main Relay (COM pin 30 and Coil pin 86), and ECU +ve supply (pin 15). When ignition is switched On, the ECU, via pin 12, earths the Main Relay (Coil pin 85, Blue/Red), and the relay is energised feeding +12Vdc (two Brown/Orange) to the injector circuits, the AFM, and ECU pin 2, where Main Voltage is monitored for injection pulse width purposes. Also +12Vdc (White/Slate) is applied to the Fuel Pump Relay (Coil pin 86) and to ECU ignition sense (pin 19). The ECU, via pin 16, now earths the Fuel Pump Relay (Coil pin 85, Blue/ Purple), the relay is energised feeding +12Vdc (White/Orange) to the Lambda sensors, the fuel pump (White/ Purple) via a fuse and the Inertia Switch, and the Purge Control Valve (if fitted).

But how does the Fuel Pump relay contact (pin 30) get its supply from the Main Relay switched circuits?

Davep. Thanks for the feedback, the fuse you mentioned that is I assume in the footwell, but what size fuse is it? and where on the fuse board would I find that?
I have a 1993 430. as my profile will show

To all of you, a lot of diagnostic information. You really know your stuff. It's great to have guys like you on the forum.

[FoxTVR430]

blitzracing said:

You mention you here a click after a few seconds- this tells you a lot. It means the main relay is working- it also means the fuel pump relay is closing at the same time as the main relay, with power from the main relay. This means either the fuel pump relay has faulty contacts or something outside the ECU loom like immobiliser, trip switch or jammed pump.

Great thanks again Blitzracing !

Simon

[FoxTVR430]

Thanks for all your comments.
When I'm next over I will look into these points.

[FoxTVR430]

SMB said:

I had exactly these symptoms a few years back, started , ran for 15 seconds then stopped. Normal failure pattern is just a simple no start, The relays are in the footwell, normally silver with an orange strip over the top. Should be 2 one for ecu one for the fuel pump, normal relays with the same pin out can be used as a get you going but replace with the correct ones Asap or the battery will drain.

Where can I get the "correct relays" from?

[FoxTVR430]

Great guys, thanks for the heads up.