No Power to injectors

[Murrayman]

Hi all,

First off apologies if i have posted in the wrong place or if there is already a forum covering this issue, i have searched for hours.

i have a 2004 clio 1.2 16v and recently it just decided not to start. after much investigation i discovered the following:

there is still a strong spark
Engine will run on easy start
Injectors are not operating
Injectors themselves work when tested individually with a 12v live and earth
Fuel pump is operating and good pressure at injector rail.
checked the earth to the injectors and that seems fine although was reporting lower than 12v i seem to recall so tried bypassing the earth with a new direct earth, made no odds
there is the coil injector light and the red flashing engine light lit up on dash, however when a live is put to the injector earth these two lights go off.
changed crack sensor
checked all fuses and relays tried shorting all relays in engine bay
checked wiring although will check harder tomorrow with a continuity tester
i am left to believe it is either the ecu at fault or a sensor telling the ecu not to inject.
i have plugged into a small snap on diag system and no codes were found all though am going to plug into a big one tomorrow.
as far as i can tell there is no pulse being sent from the ecu down any of the 4 cables going to the injectors, I'm assuming this is a switched live but have read elsewhere it is a switched earth?

If anyone can shed any light on this it would be appreciated, i have found a replacement ecu i can buy if need be.

also is there a fuel cut off switch if so where and does it cut off the injectors not pump?

sorry if i haven't been totally clear.

Thanks in advance

 

[Jamie182turb]

Are you sure it's not a immobiliser issue ?

 

[Murrayman]

i assumed there would be no spark if it was immobiliser plus the lights which flash up on dash point to an issue to do with injector system?

 

[Tkul88]

Did you get to the bottom of this in the end?

 

[James5_GTT]

Ok so what was the issue here conclusion? I am having a similar issue on my 172 cup, I have removed the injector brown relay (engine bay relay NS inner wing) and car will crank but will not start if I remove the in jector relay and bridge the connections the car will fire up fine, does anyone have a pin out for the 5 pin small relay for the Injector, it's as if it's not getting an activation signal for the injectors but car is clearly not an immobiliser issue. Where does the injector relay get it's pull activation signal from is the signal a GND pull or positive trigger??

 

[Danny197]

Check out the earth cable that runs from the gear box to the chassis you may need to remove the passenger arch liner had a simular problem. Or try linking it out by putting a jump cable from the negative on the battery to the top of the gearbox. Hop this helps?

 

[Johnny 808]

Hi all,

First off apologies if i have posted in the wrong place or if there is already a forum covering this issue, i have searched for hours.

i have a 2004 clio 1.2 16v and recently it just decided not to start. after much investigation i discovered the following:

there is still a strong spark
Engine will run on easy start
Injectors are not operating
Injectors themselves work when tested individually with a 12v live and earth
Fuel pump is operating and good pressure at injector rail.
checked the earth to the injectors and that seems fine although was reporting lower than 12v i seem to recall so tried bypassing the earth with a new direct earth, made no odds
there is the coil injector light and the red flashing engine light lit up on dash, however when a live is put to the injector earth these two lights go off.
changed crack sensor
checked all fuses and relays tried shorting all relays in engine bay
checked wiring although will check harder tomorrow with a continuity tester
i am left to believe it is either the ecu at fault or a sensor telling the ecu not to inject.
i have plugged into a small snap on diag system and no codes were found all though am going to plug into a big one tomorrow.
as far as i can tell there is no pulse being sent from the ecu down any of the 4 cables going to the injectors, I'm assuming this is a switched live but have read elsewhere it is a switched earth?

If anyone can shed any light on this it would be appreciated, i have found a replacement ecu i can buy if need be.

also is there a fuel cut off switch if so where and does it cut off the injectors not pump?

sorry if i haven't been totally clear.

Thanks in advance

Hi Murryman,
I know this is a old post but did you ever resolve you injector problem. I've got exactly the same fault.
Cheers

 

[Chris_Beer]

@Davyy ?

 

[cs_dave]

@Davyy ?

If in doubt ask a expert

 

[bloke]

@Davyy ?

apparently he closed the lid on his laptop but isn't strong enough to open it so has got to wait for his nan to go and open it for him.

 

[Chris_Beer]

apparently he closed the lid on his laptop but isn't strong enough to open it so has got to wait for his nan to go and open it for him.

"Go on young man, keep joking... But my Davyy will be back after the gym to show you boys how it's done"

 

[bloke]

"Go on young man, keep joking... But my Davyy will be back after the gym to show you boys how it's done"

is that actually his nan?????

 

[benw_172]

I'm having a similar issue on my 172, the car is cranking over but the injectors don't seem to be working, getting fuel in the rail fuel pump is running and getting spark, I've tried swapping the relays but still nothing, any ideas guys?

 

[Johnny 808]

I'm having a similar issue on my 172, the car is cranking over but the injectors don't seem to be working, getting fuel in the rail fuel pump is running and getting spark, I've tried swapping the relays but still nothing, any ideas guys?

Hello benw_172
Sorted mine- found a break in the wiring loom from the fuse box. I had to strip the loom back a bit but the break was from the fuse (large red wire) going down towards the passenger headlight. The wire has a tight kink in it as it doubles back on itself. It appears that rain water had gather in the kink and corroded the wire. I've soldered the wire back together and it turned over first time. Happy days. Hope this helps. John

 

[benw_172]

Hello benw_172
Sorted mine- found a break in the wiring loom from the fuse box. I had to strip the loom back a bit but the break was from the fuse (large red wire) going down towards the passenger headlight. The wire has a tight kink in it as it doubles back on itself. It appears that rain water had gather in the kink and corroded the wire. I've soldered the wire back together and it turned over first time. Happy days. Hope this helps. John

Cheers mate I'll have a look into it tomorrow, I've suspected a broken wire just trying to find it ahah thanks though pal

 

[Johnny 808]

Cheers mate I'll have a look into it tomorrow, I've suspected a broken wire just trying to find it ahah thanks though pal

Any luck?

 

[benw_172]

Yeah found it pal, the wire from the relay to the ecu was damaged so replaced amd it started up first time