3.9 efi injecters / fuel rail

landyady1o · Post by **landyady1o** » Fri Jan 07, 2011 9:31 pm

right guys i have had a full day on the v8 today
i got it timed perfect ticking over perfect and running perfect i left it till operating temp then went up the road in it it pulled like a train no back fire no missing so i pulled it bk in unit left it ticking over a ferver 20mins to keep me eye in water and all temps then the engin just totaly cut out stopped so i did all the cheques and my fuel rail is no longer getting a live feed to it i have fuel presure from the pump but no injecters can any body help please

DaveEFI · Post by **DaveEFI** » Sat Jan 08, 2011 12:03 am

landyady1o wrote:right guys i have had a full day on the v8 today
i got it timed perfect ticking over perfect and running perfect i left it till operating temp then went up the road in it it pulled like a train no back fire no missing so i pulled it bk in unit left it ticking over a ferver 20mins to keep me eye in water and all temps then the engin just totaly cut out stopped so i did all the cheques and my fuel rail is no longer getting a live feed to it i have fuel presure from the pump but no injecters can any body help please

By 'live' do you mean fuel or electrics?

landyady1o · Post by **landyady1o** » Sat Jan 08, 2011 8:24 am

it has no eletronic live thanks

Ian Anderson · Post by **Ian Anderson** » Sat Jan 08, 2011 2:27 pm

One / or more of the relays decided to give up the ghost?
When you turn on the ignition you should hear a click - this will fire up the fuel pump for 4 secs and also energise fuel and spark circuits

Worth starting there

Ian

DaveEFI · Post by **DaveEFI** » Sat Jan 08, 2011 4:38 pm

landyady1o wrote:it has no eletronic live thanks

Have you changed a relay? Depending on what version of the injection you have, it can have a 'special' relay as the main one. This has two outputs, switched together. Not the same as the more common 5 pin relay which has change over contacts.

One of those outputs is the +12 volts to the injectors.

As supplied, the main and pump relay are both this 'special' type. But it's only needed for the main - on the pump relay only one output is used.

landyady1o · Post by **landyady1o** » Sat Jan 08, 2011 5:40 pm

hi dave i didnt change any thing i left it ticking over sounded ( perfect) run perfect i just left it ticking over on spot to cheque all presures and temps and it cut out i was thinking a wire might or touched were it shouldnt but i have spent all day chequing think i am go in to have to resort to phone in a sparky and get him out because i am lost with it now lol thanks again

spend · Post by **spend** » Sat Jan 08, 2011 6:55 pm

Check the fuse by the relay first?

landyady1o · Post by **landyady1o** » Sat Jan 08, 2011 7:05 pm

i didnt know there was 1 i have a litle black lucas box size of a finger nail and 2 resisters ???

Ian Anderson · Post by **Ian Anderson** » Sat Jan 08, 2011 9:30 pm

Black wire (with white trace) from memory does from the air flow meter to coil

If the connection on this has been broken I believe no injection pulses are given

Ian

DaveEFI · Post by **DaveEFI** » Sun Jan 09, 2011 12:44 am

Ian Anderson wrote:Black wire (with white trace) from memory does from the air flow meter to coil

If the connection on this has been broken I believe no injection pulses are given

Ian

landyady1o says no live feed to the injectors. This should be present all the time the ignition is on. The ECU grounds the injectors.

First thing I'd change is the main relay.

Ian Anderson · Post by **Ian Anderson** » Sun Jan 09, 2011 8:22 am

DaveEFI wrote:
Ian Anderson wrote:Black wire (with white trace) from memory does from the air flow meter to coil

If the connection on this has been broken I believe no injection pulses are given

Ian
landyady1o says no live feed to the injectors. This should be present all the time the ignition is on. The ECU grounds the injectors.

First thing I'd change is the main relay.

Yes that makes sense
I wa not thinking too hard last night!

Ian

DEVONMAN · Post by **DEVONMAN** » Sun Jan 09, 2011 10:40 am

I think we need to know if the Fuel pump runs for 3 or 4 seconds when the ignition is first switched on and is there 12v at the injectors.
My TVR had a 20A fuse feeding the 2 relays which kept blowing due to a shorting injector.

Regards Denis

DaveEFI · Post by **DaveEFI** » Sun Jan 09, 2011 11:09 am

DEVONMAN wrote:I think we need to know if the Fuel pump runs for 3 or 4 seconds when the ignition is first switched on and is there 12v at the injectors.
My TVR had a 20A fuse feeding the 2 relays which kept blowing due to a shorting injector.

Regards Denis

It would be nice to know what injection it has. Earlier flapper types don't run the pump until cranking.

landyady1o · Post by **landyady1o** » Sun Jan 09, 2011 12:41 pm

the fuel pump will run for 4 seconds when you tern the ignition on the cuts off if this help s ?

DEVONMAN · Post by **DEVONMAN** » Sun Jan 09, 2011 5:28 pm

landyady1o wrote:the fuel pump will run for 4 seconds when you tern the ignition on the cuts off if this help s ?

Given that the fuel pump runs and no 12v at the injectors, I would say that you have a break in the Brown/orange wire that feeds the injectors.
(Could be a duff injector relay).

Check any multi connection plugs on the injector loom.

If it was me, I would temporarily splice in 12v via a fuse to the brown/orange wire and try starting the engine.

Regards Denis

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3.9 efi injecters / fuel rail

3.9 efi injecters / fuel rail

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