LPG wiring question. '88 RRC 3.5 efi

[pomonastik]

i have been progressively installing the front end hardware for an LPG system onto my bog-standard '88 RRC Highline 3.5 efi with flapper type afm. so far i've mounted the OMVL R90 reducer, stop valve, the diffuser and the flap opener.
i now want to move onto wiring in the Sprint-DmrkII SGA7642 lpg control module.(i have attached the installation sheet including wiring diagram below).
my principal question is where to splice into the injector circuit. in the diagram it shows cutting a single wire to each of the two banks but my workshop manual shows all 8 injectors being individually wired back to the ecu. i was hoping someone else might have been here before and could suggest a neat and preferably simple point to interrupt the circuit.
as i'm leaving the installation of the new supply line from tank to stop valve to a qualified fitter at a later date i'm hoping that i will be able to continue operating on petrol even after putting in the control box by forcing a petrol only mode. what do you reckon? will it work ?

[Lotz-A-Landies]

,,, i was hoping someone else might have been here before and could suggest a neat and preferably simple point to interrupt the circuit.
as i'm leaving the installation of the new supply line from tank to stop valve to a qualified fitter at a later date i'm hoping that i will be able to continue operating on petrol even after putting in the control box by forcing a petrol only mode. what do you reckon? will it work ?
Pom....

I did the electrical side of my LPG installation, and while my vehicle has a Motec ECU, the vehicle the system came out of was an 88 EFI system that I am assuming is the same as yours.

The injectors were cut with a single relay adjacent to the ECU under the drivers seat (and is the same place my Motec harness is cut without using a relay.)

It you leave the system switched to petrol the Sprint unit is inoperative.

Diana

[pomonastik]

thanks diana

and while my vehicle has a Motec ECU, the vehicle the system came out of was an 88 EFI
there is a certain irony in that my gas system came off a car fitted with motec ecu and is going onto a standard vehicle . exactly vice-versa so that is why the only new component i've bought is the afm flap opener.
when you say a relay was in place at the original ecu i presume that was a substitute for the control function offered by the sprint unit, simply triggered to open circuit the injector line when the lpg was on. as there is meant to be an overlap between gas 'on' and petrol 'off' i want to let the electronics decide the injector on/off function. perhaps that's why the relay is considered unnecessary on your motec system ? what lpg control box are you using ?

[tony]

On my 88 RRC I cut 2 brown wires (that control the injectors) they ran in the big bunch of wires behind the AFM, easy

T

[pomonastik]

'onya tony.
that was the kind of very simple answer i was wanting to hear. i've already had a look at mine and the two big brown wires stick out like the proverbial dog's appendages. as you say, once you know it looks easy.
here's to pulling up at the gas bowser soon !