Help - TR6 no noise from Fuel Pump

[Geoff Lovegrove]

A bit of advice please. I have a 1972 CP TR6 which has been going very well, I went to start yesterday and immediately knew I was in trouble - no noise from the fuel pump and no waring lights. The engine turned as well as usual and the warning lights appeared but of course did not start. So far I have checked fuses - all OK and the inertia switch which although in position was actually not connected, I have discovered this has already been bypassed - the wires have been joined and sit underneath the switch.

Where to start - any advice much appreciated.

Geoff

[cp25616]

Geoff 1st thing is to establish you have power at the fuel pump, I presume its a standard Lucas pump? This is easily done using a simple light bulb, like the type fitted to the rear lights. If you have power to the pump then that rules out any fuse issue so basically it must be the pump itself. However I for one can'r remember a Lucas pump just giving up like that, cavitation yes but not a total seizure, let us know please?

Regards

Alan G

[aardvark]

Geoff.  Have you checked for current at the pump?  Have you got the pump wired via a fused relay and if so have you checked those too?

Cheers

Dave

[BlueTR3A-5EKT]

Have you got a grey plastic thing attached to the bulkhead under the bonnet that looks like this?

If so pull the small diameter top bit upwards till it clicks then push it back down again.   This is the inertia cut out switch which is a direct electrical connection from electrical power to the fuel pump and they do go high resistive. 

[rwest]

10 hours ago, BlueTR3A-5EKT said:

Have you got a grey plastic thing attached to the bulkhead under the bonnet that looks like this?

If so pull the small diameter top bit upwards till it clicks then push it back down again.   This is the inertia cut out switch which is a direct electrical connection from electrical power to the fuel pump and they do go high resistive. 

Geoff mentioned that the inertia switch being bypassed in the original post.

Geoff - I would suggest replacing and re-instating the inertia switch anyway, you really don't want a 125psi jet of petrol going into your engine bay if you have an accident.

[Yellowperil]

I had a similar thing recently, turned out to be a failed relay

[Mk2 Chopper]

Sounds like you have a few electrical issues, with the warning lights not coming on, perhaps the ignition switch is failing. 

As the others have said, check you have power to the fuel pump first, if you do the problem is the pump, if you don't check you have power from the ignition switch to pump. 

Gareth

[astontr6]

16 hours ago, Mk2 Chopper said:

Sounds like you have a few electrical issues, with the warning lights not coming on, perhaps the ignition switch is failing. 

As the others have said, check you have power to the fuel pump first, if you do the problem is the pump, if you don't check you have power from the ignition switch to pump. 

Gareth

In situations like this you really need a Multi-meter to find out where the voltage stops. Good points are raised in the thread above. Years ago I did have a Lucas pump give up outside a Lucas dealership where it was easy to sort. So they can die without notice. Lastly you say that the inertia s/w has been bypassed. How good is the cable jointing as this may be the cause of the problem?

Bruce.