Injector firing problem...

[DD]

Hi folks,
First post but, unfortunately it's a problem looking for a solution....

3.5efi originally from a Rangie (1986 I think). Has not been modified. Has run sweet as a nut since I had it apart to do head-gaskets a year ago. On Sunday it simply cut out on me and it won't fire up. Cranks over OK, but won't fire.

Fuel is there, return fuel OK.
Spark is good and strong.
Plugs are DRY.
Engine WILL fire and cough if I connect the cold-start (9th) injector.
Engine will simply turn over on the starter if I remove the 9th injector.
Not sure about fuel pressure....but doubt the regulator would result in no fire-up at all?
Have checked the relay for the injectors - ok
ignition is the newer type with the ampifier on the side of the dizzy rather than the box under the coil.

Have changed ECU for a spare - same problem.
Earths seem good.

1 thing springs to mind - the magic silver box made by the prince of darkness himself. Is injector firing controlled by this (the 2PC resistor pack).? Reckon it's dead?

Any help appreciated....
Cheers,
Don

[katanaman]

check you have voltage at the injectors if not it could be the resistor pack, could also be some other wiring fault mind you. The injectors are permanently fed and its the ground that is switched. Also check all the connectors are good as they have a habit of failing.

[jrv8]

Hi
Sounds like the ECU may not be running.
Check the extra connection on the coil negative (-). This is the start signal for the ECU. It can be fed to the ECU either straight through a resistor or sometimes through a relay.
Earth connections on the back of the nearside cylinder head also can give problems.
Have you checked for +12v on the brown wire feeding the injection loom ? and also switched +12v on the white wire ?
Jim

[DD]

cheers guys, gives me something else to check!