Can you confirm if you can/cant hear the fuel pump run for a few seconds when you turn the ignition on.
As Rox pointed out about the wiring for the TPS, the center wire of the three(should be white) is the variable output from the TPS.
Dave
I’m sure I can’t hear it, there’s no noise after I disarm the immobiliser / turn on the ignition.
It’s not the TPS as I’ve just changed it with an Elise (just down the road from me) but to no avail. Same, turns over, sparks but no juice getting to the cylinders 
I’ll get the PX seat out tomorrow and check all the wiring above the fuel pump. I just hope no electric is getting there and it’s not the fuel pump that’s packed up!
[quote]I’m sure I can’t hear it, there’s no noise after I disarm the immobiliser / turn on the ignition.
Are you really sure you can’t here it, its quite distinctive, and quite pronounced, and lasts for three seconds, turn the key to its second position, the one before you engage the starter motor, if the fuel pump turns you will hear it. The reason I’m being quite particular is it will help diagnose what the problem is if the fuel pump runs or not.
If you definatly can’t here it lets look at the circuit diagram for for the fuel pump and coil, it goes something like this.
Live feed is supplied through fuse B1 20Amp ( check this fuse is good) then through the fuel/injector relay and then onto the fuel pump before returning to ground.The injectors are also feed through the same fuse and relay and are controlled by the ECU. Hopfully you are following this so far.
Next, control of the fuel/injector relay, this is feed from pin 53 of the ECU through the coil of the fuel/injector relay(causing it to close/ energise) and then returns to ground through the Inertia switch.
So what does all this mean.
Well your problem could be one of, or several of the following.
Fuse B1
Fuel/injector relay
Fuel pump
Inertia switch
Wiring fault.
If its none of these It could be that there is no output from the ECU on pin 53, I,m not really sure what is neccessary for the ECU to be satisfied to energise pin 53, the only other sesnor/inputs for the ECU that I can see are
- Cranckshaft position sensor
- Manifold absolute pressure
- Engine coolant temp
- Exhaust oxygen content
- Throttle position
- Vehicle security signal
- Starter signal
Not sure if any of this helps, but I’m half cut , which doesn’t help when looking at circuit diagrams, especially if you dont realy know what your doing.
Dave
OK, looks like the fuel pump is fooked Very bizzare for one to get at such a young age… But I guess it has been ran at high pressure for the whole time
So anyone know how much a fuel pump costs? Or anything else as to why it isn’t energising?
One the 5 pins going to the fuel pump one had a constat 5v (bottom right looking at the connector into the fuel pump) and one which was a smaller voltage but all the rest seemed as nothing was going on… I’ll keep you’ll posted, I just hope it’s sorted before Oulton!!!
Also everything else seems OK, it fired up great on a bit of brake cleaner I just need to wire up a few can’s of that instead LOL!
Before you condemn the fuel pump, I think you need to do a bit more digging, looking at the circuit diagram, it looks like the fuel pump should have 12v going to it, If you can, disconnect the wires going to the fuel pump and measure the voltage between them and ground again.
Dave
Hi Dave,
Yep actually it does look that way… Does anybody know what wire the 12v feed should come through? (there’s 5 wires going in / out).
The Orange/White wire carries the 12V to the pump from the relay, the Yellow is for the fuel injectors.
I hope its not the pump as thats a fuel tank out job and i believe a couple of hundred quid for a new one
Phil�s right, the five wires you see look like two live feeds, two earth returns, and the filth is probably an earth for the fuel pump.
The service notes say the following for the fuel pump for an Elise, which are probably the same for the Exige.
Fuel pump switching.
The fuel pump is controlled by the ECM via the fuel pump relay and is energised under the following conditions.
1.When the ignition is first switched on, the ECM grounds the pump relay coil for a few seconds in order to pressurise the fuel rail, and them switches off.
2. When cranking, the ECM receives an engine speed signal and operates the pump continuously.
3.When the engine is running, the ECM receives an engine speed signal and operates the pump continuously.
I think you need to check if your getting 12v to the fuel pump, disconnect the wires going to the fuel pump and measure their voltage with respect to earth, don�t forget if going off the above, the relay only energises for a few seconds when you first put the ignition on, if your getting 12v then the problem is probably your fuel pump, if your not getting 12v then the problem is elsewhere.
Have you checked the fuse for the ECU.
I’ve got a spare copy of the service notes on disc, they might help, let me know your address and I’ll post them off to you if you want
Dave
Just a couple of corrections with what Dave has said…
The ECM does not ground the fuel pump relay, it is grounded by the inertia switch, the ECM switches a +12v to energise the coil.
To confirm if the fuel pump is working, identify the ground wires, disconnect the fuel pump and apply +12V directly to the orange/white leading to pump, if you dont hear the pump then the wiring leading to it or the pump are fooked.
There is some slight memory that someone else had this problem either in an Exige or Elise and it was the wiring that was chaffed.
Cheers guys,
I’ve got the service manual (in PDF) but the wiring diags are poo, doesn’t have any colour for the wiring or anything, complete PITA
I’ll check the Orange / White wire for a live feed, and if there’s nothing then that’s better news but still then gotta get into the loom I guess.
Thanks again, I’ll keep you posted
Just had a quick look at mine, when I turn the ignition on I can hear the fuel pump relay make, and buy putting a finger ontop of the relay can also feel it make, can you confirm if you can hear your fuel pump relay making.
Dave
Next idea, to prove the output of the ECU to the relay, remove the relay, look at the back of the relay and find terminal 85, now find the corresponding slot on the relay socket and measure the voltage at the socket with respect to earth with the ignition on, I had 13v, this will prove if your getting the correct output from the ECU, if your not then were looking at other things rather than fuel pumps.
Also have you checked the ECU fuse yet.
Dave
Dave
Excellent! Thanks for the pointers Dave… You’re in for some serious beer tokenage
I can’t check until tonight so hopefully the rain will hold off and I’ll have me torch and multimetre ready
Just had another play and found that either of the fallowing faults will have the same symptoms as your snag.
Blown ECU fuse
Defective ECU relay, this is the top one of the three
Suggest checking these two first, as they’re easy to do.
Dave
I’ll check those, but have checked all the fuses… So with no ECU the engine still turns and sparks?
Not sure about the sparking, I just pulled the relay out, fuel pump doesn’t run, but the engine still turns over.
Dave
Right, I’ve just checked and yes the it still sparks with the relay removed, so fingers crossed lets hope its a knackerd relay.
Dave
Fingers crossed in a big way! I should be able to swap it for the starter solinoid relay should I? Obviously it won’t start but I’ll hear the pump pressurise and be able to check for 12v going in…
Dave you are a star!
Yep, or fit the headlamp relay, its the same type.
Dave
Sweet, I’m off home now so will post my result tonight fingers, toes, ribs, nural pathways, guts and innards, spinal column and kidneys all crossed