Hotwire fuel injection wiring

[MogLite]

If you'll excuse the pun, I'm trying to tidy up the loose ends of wiring on the EFI - 1990 Hotwire out of a RRC.

There is a coolant temp sender - on the front of the inlet manifold for the coolant temp gauge, I've replaced this with a sender for a VDO gauge, I believe the EFI uses a separate coolant temp sender - can someone confirm please ?

Road speed transducer - I'm guessing this is in the BW transfer-box under my workbench, as I've swapped in an LT230.

I'm assuming I can get it running and idling without, do I need to connect the lead temporarily to a constant earth or +12V, to get it running.

Do I need one going forward ?

Does it need to be acurate, with my gearing/tyre choices that might not be possible

Editted to say I've found some info on the speed transducer here and its nothing like what I was expecting.

I've got a G-reg donor vehicle in my yard, that hasn't got a speed sensor, is this therefore the earlier 14-CU EFI, whereas MogLite has the 1990 14-CUX ?

Thanks all

[Bull Bar Cowboy]

Andy,

The ECU coolant sensor is on the inlet manifold near no1 cylinder, behind the dizzy .....( IIRC it’s the same as for flapper 14CU)……… its coloured blue. There should also be a fuel temp sensor (not used on flapper ......only 14CUX)

Yes you need the speed sensor for hot wire ………. On the LT 230 there are 2 types ….one bolts into the LT230 speedo gear housing and the other is in a splitter box on the speedo cable ……. IIRC its bolted to the chassis.

Ian

[dirtydiesel]

I seem to remember from the dim and distant past, that there was some kind of conection between the road speed sensor and the lamda sensors, in that once you've changed the tune resister to a non-cat one the ecu no longer needed the road speed sensor.

But then again it has been a damned long time since i've looked into it.

Your best bet could be to give mark adams a ring on 01694720144, i think you have to call before 11am to get an answer.

[Tomcat Nev]

You can remove the Yellow road speed sensor wire and have it unconnected. As i remember it is effectively a switch to tell the ecu whether the vehicle is moving above a certain speed. It is used for the fuel cut off on over run to help reduce MPG. I have dispensed with on two vehicles as it was causing problems because when it fails it can fail your injector drivers too!!!!

The only effect we noticed was an increase in fuel consumption on one of the cars. The other is the Tomcat - but i don't notice consumption on that .

You will also find that when people put the hot wire V8 into Capri's etc they also do not bother with the speed sensor.

Cheers

Nev

[Hybrid_From_Hell]

I had all this on my old Hybrid.

NOT running the road speed sensor will result in a lumpier tickover, possibly stalling for no apparent reason when sitting on tickover for any time.

Nige

[jules]

I had all this on my old Hybrid.

NOT running the road speed sensor will result in a lumpier tickover, possibly stalling for no apparent reason when sitting on tickover for any time.

Nige

I never connected mine for three years on the 4.2 and didn't suffer any of these problems

apart from time related fuel economy as it drank fuel too quick to measure by the mile

[MogLite]

Thanks for the input everyone, thats another couple of mysteries off the list - more along later

[Guest diesel_jim]

I had all this on my old Hybrid.

NOT running the road speed sensor will result in a lumpier tickover, possibly stalling for no apparent reason when sitting on tickover for any time.

Nige

My old 90 which had a 3.9 14CUX did exactly the same thing.

Andy... i found the transducer off of the 90 in the garage the other day when i tidied it out (what a scarey job that was!!)... it's the transducer and the 6" or so of cable that connects it into the transferbox.

yours if you want it? PM me for details.