fuel pump not running when moving air flap?

[johntom]

Hi
Seems to be one thing after another at he moment!

I have spent the afternoon fitting an FSE fuel pressure regulator, all went well until i tried to set up the pressure as per the bible stall test. I have removed the air filter, disconnected the black/ whites from the coil, clamped the return line, turned on the ignition (position 2) - however when I move the flapper the pump doesn't run!

I have just started driving the car and increasingly the car doesn't start first time. When the key is turned from pos 2 to start, nothing happens, however it has always started after a few attempts - I suspected he ignition switch as it felt like I had to turn it a bit harder somehow?

Now the car won't start and the pump doesnt run as above, I am thinking it might be an immobiliser issue (toad system fitted with a little tag next to the key - doesn't plug in just sensors it's in the car)?

How do I determine if it's the immobiliser or something else, ok with the a multimeter etc ?

[vampire222]

immobiliser would disable the ignition, not the pump as far as im aware of. check the fuel pump fuse and relays. if all else fails a direct cable can work out, i'm still using that on my car after it mysteriously refused to power the pump legitly.

[Wedg1e]

Depends how many disable circuits the immobiliser has and how well it was installed. When I did car security we'd use something like a Vecta 4-circuit unit and would cut stuff like ECU power, fuel pump feeed, ignition feed, lights etc. depending on how bdly we were feeling
On some units you could also arrange wires to short to ground so if the toerags tried hotwiring circuits they either got a hell of a fright from the sparks or their wiring caught fire
Then the industry poohed itself and nowadays I think they only go for starter motor and maybe fuel pump feeds.
But I bet it's not the immobiliser

[johntom]

Hi
should the fuel pump have power and prime on ignition position 2 ?

I only suspected the imobilisor because there's no fuel pump or starter motor action and I've had probs with 3 previous tvr's. I remember unlocking the passenger door on a wedge and watching in amazement as it began to move down the drive on the starter motor!!

I don't have the wiring diagrams to hand until tomorrow, any pointers or likely suspect circuits/relays ?

Edited by johntom on Monday 13th August 00:03

[Wedg1e]

Right, in your earlier post you said the car had got 'increasingly harder to start'... is this a case of cranking like hell but not firing? Or is it that you turn the key to the cranking position but the starter doesn't engage? If the latter, it's probably just the solenoid needing a clean or a poor connection to the spade terminal - my car suffers from both conditions from time to time.
If it's the former problem (lots of cranking but no start) then this ties in with your noting that moving the AFM flap doesn't start the fuel pump... so you could be looking at a loose connection, broken loom, bad earth...

[johntom]

Hi and thanks for replying
At cranking position, nothing happens ie no starter motor, which sounds like the solonoid etc but why no fuel pump when I move the flapper? The bible wiring diagram shows power branching off to the fuel pump etc before the starter/solenoid so shouldn't I still get the fuel pump running?

Also where is the fuel pump relay located ?

Edited by johntom on Monday 13th August 11:13

[Wedg1e]

Fuel pump relay is usually on the panel with the rest of them! Find it, pull it out, make a wire link and poke it in the 30 and 87 terminals of the socket, that should start the pump as soon as you turn the ignition on. At least it'll let you do your pressure test.

[johntom]

Hi
I only have the bible relay plan which doesn't show the fuel pump relay, couldn't remember if it was on a flying lead in a previous car, might have been a Griff.

[johntom]

Hi
I removed the fuse board and identified the starter, fuel pump, main relays etc from the wire colours. I could see where the imobilisor had been spliced into the starter and fuel pump feeds, so I tested for 12v before and after the imobilisor wires with the ignition key in the start position. Sure enough 12v before the imobilisor wire joint, nothing after. The 'Toad' is in the bin and the car started first time!
4 Tvr's and 3 bad alarm/imobilisor's!

[ralph350i]

johntom said:

Hi
I only have the bible relay plan which doesn't show the fuel pump relay, couldn't remember if it was on a flying lead in a previous car, might have been a Griff.

Dont know if this will helps mate, but have tried to show you the fuel line plug, i don't have Efi, so the relay has been removed and as shown it's the white plug in which the Yellow wire is the fuel pump feed and the white wire is the power feed, link together and you should get power, if not check fuse, good luck, Ralph

[Wedg1e]

johntom said:

4 Tvr's and 3 bad alarm/imobilisor's!

Guess I stand corrected then

[johntom]

Wedg1e said:

johntom said:

4 Tvr's and 3 bad alarm/imobilisor's!

Guess I stand corrected then

Not at all, your help is always valued. I have perhaps just been unlucky with alarms/imobilisors, after all they're probably years old . At least in the future it won't be a consideration with fault finding.