fuel pump mystery!?

[s.aldous]

hi, every time i go to start up my 172 phase 2 the fuel pump doesn't kick in until i turn the ignition on, turn it off again and then turn it back on. ( if this make sense) does anybody know why it does it?

its bloody annoying!:S

 

[DrR]

I take it doesn't start first try then?

 

[s.aldous]

no it never start first time, it just tick over but when i try again it then starts. do u have any idea y mate? cheers

 

[DrR]

Sounds like the TDC sensor fault to me?

I can never here the fuel pump prime up anyway, so not sure what you're hearing.

 

[s.aldous]

ok il get that looked at, also i can hear the fuel pump prime up which come from under the car but only when i do the ignition thing (on, off and back on again)

 

[DrR]

The whining noise is the throttle body? That noise?

 

[s.aldous]

no dont think its a whining noise, its more like a deep humming which last bout a second, sounds like it coming under the front seats or there abouts as soon as lights on the dash come on when key is turned to the first stage

 

[s.aldous]

when i mean first stage, i mean two clicks before the engine will tick over or start.

 

[DrR]

No idea then, nothing I've ever heard car makes loads off odd noises though lol. TDC sensor is common fault that stops car starting first go, my old 172 did it to.

Have a search for TDC sensor, should be few threads about it

 

[s.aldous]

ok will have a look, thanks m8

 

[craigy2703]

my pump does this did you ever fix the problem?

 

[Terry172]

Fuel relay in the engine bay not working properly? Replacing that could help (one of the brown box relays). I know what you mean about fuel pump priming noise as I can hear mine every time

 

[bmh.01]

Sounds more immobiliser related than anything else, does the light go out in the clocks when it won't start?

 

[craigy2703]

It only happens if you lock the car unclock it turn ignition fuel pump not prime if your turn ignition off then on it primes if you lock car then do it it happens again heard a few people's phase 2 do it normally as I thought it would never start first but it does just sum times not in morning first time

 

[Jonny1*2]

try swapping the relays around. Can't remember if the 172 ones are the same as the 182, but the fuel pump is a small black relay closest to the headlight. Just swap it for one of the others and see what happens.

 

[craigy2703]

Done this sill same really annoying me now cranking for ages first start in morn but second fires straight up

 

[Steve182sport]

Done this sill same really annoying me now cranking for ages first start in morn but second fires straight up

Hi did you sort out the fuel pump problem mine does the same thing I have to turn the ignition on and off until I hear the pump prime pain in the backside