The V8 Owners Forum -

Hi all ive got 2 ?? for you , first ive changed the lam sensor as the lumenition a/r meter used to go red to green all the time, well i got a new sensor wired it up and know it just stays on the first red, i wired it up the same as my old one, . Next ?? is i need to put a relay in the fuel pump wiring ,where do the wires go on the relay for it, on the relay is nu 30 which is ground ,but where do the power wires go 85 ,86 , or 87. advice as always needed rich

Sadly....as the Lumenition system uses a narrowband sensor, its pretty useless anyway ( unless its a new model )

Are you sure you wired it up correctly though ? Was it a 3 wire of 4 wire ? Have you run the engine and driven it at full operating temperature ?

its a 4 wire sensor, i followed the diagram for the wiring, as its a narrow band does it need to be wired different ??

bones wrote:its a 4 wire sensor, i followed the diagram for the wiring, as its a narrow band does it need to be wired different ??

4 wire will have two same colours for the heater. Simple +12v and ground

The other two wires. One will be a sensor reference ground, and the other a signal wire.
Cant rem the colours of which is which, but they are usually black/grey I think.

Despite the heater, often they still dont work correctly until up to a sensible operating temperature, and this too will depend how close the sensor is to the engine.

If it's miles away, it may never get up top temperature.

Might be an idea just to sick a digital volt meter across the sensor, and watch its output. It may be fixed at one end of the scale, because thats what mixtures it is seeing. Does it change when blipping throttle...over run etc ?

2 white wires are heater, black is signal out and grey is signal common ?. The sensor is just back from the y-piece so its in a single pipe roughly under the drivers seat on my sd1, is it better to fix one sensor each sdie of the manifolds,

Grey would be signal ground. Basically a good sound ground.

Slap a voltmeter across the black and grey and monitor.

That does sound quite far back. Id imagine you'd need to be driving to get any sensible figures from it. It may work at idle...but I suspect its response could be quite sluggish.

even when driving it never moves, i better go through the wiring and check it out again,if the wiring is ok,then i will at a later date have the sensor moved forward, another job for sunday, thanks for the replies, just to need find out about the fuel pump and relay know rich

I think- (will check in a bit) that on the single pole normally open relay for my lambda heater i have the "trigger" for the relay on 85, that being grounded through 86. The high current side is then connected through 87 and 30 with a 5A fuse inline.

My Bosch sensor had the same colours as mentioned above- white, white are heater connections, the black is signal out, and grey is signal common.

My sensor is in the exhaust Y-piece just after the join and seems to work OK, in that i can see on the LPG unit the mixture go rich on acceleration, then lean out when i go to cruise before the unit then corrects and goes to stoich (red and green lights on).

Any throttle movement from this cruise will then temporarily upset the mixture until the box compensates again. Ideally i need to get it leaned a little for cruise so that the adjustment needed by the box is just out of the mixture valve's range and prevents it richening it back.

i need to fit the relay into the fuel pump side if things, rich

Ah.

Then connect whatever becomes live when you want the pump to run to 85 and ground through 86, and then connect high current feed to 87 and the pump to 30.

You kind of just imagine wiring whatever it is with an inline switch, and then replace the switch in your head with the high current side of the relay.

Some relay stuff here.


http://www.airheads.org/content/view/159/49/

If you were actually asking a more complicated question and i have missed the point again, then apologies for teaching you to suck eggs!

Hope it helps.

Nice link that. Some useful info on relays there.

that is a good link, the nos side is wired different to how they say the relay works??