Discovery 2003 V8, ECU pins for Gas System.

[ModchipMan]

Hi
I have a 2003 V8 Landrover with SGA299 Gas System that was fitted by I dont know who.
anyway , I made a cable and found software for this system,
my problem is when you slow down from 100km with no throttle the gas system looses its Tacho signal displayed on the SGA299 software but still works on dash and the OBD2 Portl, and switches to petrol then when you put the throttle on it works again and switches back to gas, if you throttle to much it does backfire.

What Im after is the pin outs of the discovery ECU to where the gas system should connect up to,2 x o2 sensors, TPS Signal, Tacho Signal, etc

attached is the Wiring Diagram for the SGA299. it also covers AEB/295-298 systems.
So I hope some one can help me out.

[bee utey]

Tacho signal on those is a white wire with a grey (=slate) stripe (WS,0.5 in the pic) running up to the instrument binnacle. The installer probably used a petrol injector signal instead.

https://www.aulro.com/afvb/attachments/lpg/132620d1511606437-discovery-2003-v8-ecu-pins-gas-system-disco-2-wiring-3_cr.jpg

132620

BTW it will always backfire at some point, coil pack ignition systems are well known for it. LPG sequential vapour injection is the only type I would use and recommend these days.

[bee utey]

Only front sensors in Oz.

https://www.aulro.com/afvb/attachments/lpg/132621d1511606895-discovery-2003-v8-ecu-pins-gas-system-disco-2-wiring-2_cr.jpg
132621

[ModchipMan]

That would make sense, that its wired to an Inj, cause thats what it is like, fuel cut on decel, but cuts tach signal, thanks for that.

Would you know which of the TPS pins is return the signal.

Also I have noticed that most of there preloaded files including the program loaded to SGA299 for each vehicle all use switch to gas on Acceleration, this would always cause backfire on heavy footed people, so I changed mine to Deccel, and now it does not backfire on changeover.

So with your info I should be able to fix the tacho input drop out and then it wont backfire for that reason either.

my TPS is wired to a Blue/yellow wire that sits at 0.3v, at all Throttle positions, so im guessing its wired wrong to..

Thanks Heaps for your help bee uty.

[ModchipMan]

All sorted, thanks heaps to this forum.

I had to set the gas ecu to 4cyl to get the RPM right, but all works 100% now, no backfires so far..

Thanks again..

[ModchipMan]

C0637-17 for TPS 0-5v
C0636-24 for tacho signal.

The ECU connectors must be the best design i have ever seen, they should ISO.
The lock in clamp, 10 out of 10
The way it comes apart to expose the connectors and numbering 10 out 10.
I wish all connectors were like these..