No Fuel Pump or Stepper Motor

[Andy. G]

Well, been tinkering in the garage over the last couple of nights, tidying a couple of areas of the chassis and replacing engine mounts.....
....now just tried turning the key, and no fuel pump priming and no stepper motor noise???

Off the top of my head ecu or ecu fuse seems the only likely common factor??
Looks like The Bible will be my bedtime reading

Any suggestions??
'93 Chimaera

[Mark_G]

Possibly an issue with the immobiliser - there's been a few threads on this type of problem recently. Sorry don't have more details to hand.

[Andy. G]

Mark, immobiliser was my first thought, just looking through wiring diagram seems ecu is the common factor as it directly supplies both pump and stepper motor

Unfortunately I've got the narrowest garage known to man, will have to get the car out of the garage tonight to have a look in passenger footwell, see if I can make some sense of whats going on.
First test ecu fuse then see if there's 12v output from ecu to pump, if these are ok then the fun begins with alarm/immobiliser

[Derek Smith]

I have a 93 Chim and my stepper and fuel pump only receive power once the immobilser is switched off.

[Andy. G]

Derek, thanks, thats very interesting....assumed immobiliser only deactivated fuel pump....although I was hoping it wasn't going to be an alarm problem

[bubblebobble]

Howdy,
I am very well versed in the alarm systems fitted to all tvrs, drop me a message if you need any help at all.
No need to worry the alarm/immobiliser isnt a black art as most people are led to believe.
You can simply bypass the immobiliser ignition/starter relay with a simple loop in 2 minutes, thus either confirming or eliminating the immobiliser.
HTH

[bubblebobble]

just a quick thought, have you checked the ignition relay? check you have 12v at the coil in the relay. you can use a jumper between pins 30 and 87, if the fuel pump springs to life then it is "most probably" the relay.

[Andy. G]

Thanks BubbleBottle, might drop you a mail tomorrow if I can't make any sense tonight,didn't really look into it last night as it was gone 11 by time I appeared from under the car scratched and bruised after changine engine mounts
...it is however not the standard issue TVR alarm

[blitzracing]

You dont hear the stepper on power on, only power off, so remove this from the equation!

[bubblebobble]

Dont worry about what alarm it is, the main thing is the existing colour coded wires on the car loom which are broken to feed the immobiliser

[Andy. G]

Mark, from memory if you turn ignition on and then off you would hear stepper ???

....but you don't on mine at the minute...

[Andy. G]

Well, popped home for a late lunch...
Car drove had been working faultlessly last time I used it, so retraced what I had been working on, including retightening nearside manifold bolts.
Checked for anything that may have been disturbed, wiggled AFM loom around and fuel pump leaps into action

So all I need now is to trace which wire is broken/shorted/loose

All being well should make it to the pub for 8

[blitzracing]

Andy. G said:

Mark, from memory if you turn ignition on and then off you would hear stepper ???

....but you don't on mine at the minute...

It retracts on power off, but wont move from its retracted position untill the engine starts and rev's too high, so it moves out to try and slow it. So no go, it wont move.