Immobilser Advice Wanted

[Harry Harris]

Hi
Still getting to grips with my recently acquired '96 Chimaera.
One remaining concern I have is regarding the immobiliser.
When I disable the alarm and get into the car, initially the fuel pump is not enabled (eg silence).
I have to then just 'blip' the key fob button again and then when I turn the ignition key; the pump runs and car starts OK.
Is this a common/expected feature, or does it indicate a fault or weakness in my immobiliser unit??
Any advice or guidance would be greatly appreciated.
Many thanks Harry

[ianwayne]

Presuming you have the standard Meta alarm, if you don't turn the ignition on within 20s of unlocking it with the fob, the immobiliser rearms itself.

Also, if there is plenty of pressure still in the fuel line, the pump will only run for a very short period. It won't run again until you start cranking the engine.

[Steve_D]

ianwayne said:

.......Also, if there is plenty of pressure still in the fuel line, the pump will only run for a very short period. It won't run again until you start cranking the engine.

Minor point but worth mentioning the ECU does not know the fuel pressure. The pump prime with ignition turn on is a set time period. As you say it then does not run again until the ECU detects engine revolutions.

Steve

[Penelope Stopit]

Steve_D said:

ianwayne said:

.......Also, if there is plenty of pressure still in the fuel line, the pump will only run for a very short period. It won't run again until you start cranking the engine.

Minor point but worth mentioning the ECU does not know the fuel pressure. The pump prime with ignition turn on is a set time period. As you say it then does not run again until the ECU detects engine revolutions.

Steve

As above the ECU has no idea of the fuel pressure and the pump is always powered up for a set priming time
The thing is, if there is plenty of pressure in the fuel lines when switching the ignition on a person could be fooled into believing that the pump hasn't primed because many pumps run quieter when not having to build the pressure up

[Harry Harris]

Many thanks for all your help & advice, problem was indeed due to the time-out of the immobiliser.
Sorry for the dumb question, (I had read about the immobiliser operation, but just went into panic
at the thought of an alarm/immob.malfunction).
What a brilliant & useful site PistonHeads is !!!!!