Lambda sensor heating working around-the-clock

[StefanK]

Hello, I am Stefan, posting from Germany and have to apologize for mistakes in writing.

After 30 years I have made an old dream come true and bought last November in Holland a TVR, a Griffith 500 RHD, Modell 1996.

At first I have my no big thoughts about the fact that the former owner installed a kill switch to disconnect the battery. I thought it makes sense in a car which is not driven that often.

Meanwhile I detected a big current (2 Amps) which is discharge the battery within a day.
With an infrared-thermometer I found out, that the lambda sensors heating is working all day long.
Each lambda sensors takes 1 Amp.

So, I do need YOUR HELP.
Has anyone hhad such a problem?
What was the reason?

Where do I find a wiring diagramm where the Lambda sensors are marked.
I assume it could be a wiring diagramm for the injection or ECU.

I hope someone has got a clue what is wrong with my car.

Thank you in anticipation.


Best regards / cheers!
Stefan Koehn

[blitzracing]

Someone has been in there modifying things then- the lambda heater supply is the same one that drives the fuel pump, and you know that if it was running all the time. The wring is basically much the same as the Range Rover as the TVR uses the Range Rover ECU loom. LandRover manuals here- Use the last one in the 14CUX manual for the catalyst car.

https://www.dropbox.com/sh/hrmkjqe0a4i4nv1/AABrckk...

[Steve_D]

In the passenger footwell you will find the ECU and a number of relays.
At the end of the loom are two relays one in a black base and the other in a blue base. The black is the ECU relay the blue is the fuel pump relay
I suspect someone has fitted the wrong relay type in the blue mount.
Pull the relay and check the pin numbers marked on its base....you should have 30, 85, 86 & most importantly 2 pins marked 87 not 87a or 87b.
When the relay is activated it puts current from pin 30 onto both the pins 87. One of these does the fuel pump the other supplies the lambda heaters.

Steve

[StefanK]

Thanks to blitzracing and Steve.

I hope the problem is the (wrong) fuel pump relais.

In this context I have detected a mistake in the wiring diagram shown in the "bible" on page 84.
There is stated, that the relais (both) should have 87 and 87a pins, but - as Steve mentioned - it should be 2x 87.

[Loubaruch]

Further to Steve D's post

You may find this diagram helpful:

http://www.bertram-hill.com/fuel-pump-schematic.ht...

The Lamba feed from the fuel pump relay connects to the second pin 87, not connected in the diagram.

[StefanK]

The fault was a wrong fuel pump relay. As stated earlier, the right one has 2 "87" pins.

[BIG DUNC]

Thanks for posting the outcome. It is always good to find out what the solution to the problem was.

[Steve_D]

When do I get my prize?
A virtual rum and coke will do nicely.

Steve

[StefanK]

Cheers Steve!