S

sjw-eng

New Member
Hello All.
Yes great i've myself a 1994 disco V8 3.9 Efi and its got a gas conversion. Problem is it runs like a bag of bolts at low revs, on petrol all is good, but switch to gas it ticks over nice and when its going it flies. But try and pull away from the lights and you've got a kangaroo under the hood. So what can i do? how do i check and retune the gas control with just the basics.
The gas box is a "blgas" unit if that helps it has three screw on the unit and one on the pipe, what do what and how do i set up by ear.
 
If its an efi , it should have a stepper motor between the vaoporizer and the inlet manifold, which adjusts the gas/air mixture depending on load requirements, with data taken from the lambda sensor.If you follow the gas pipe out of the vaporizer, you should see it with an electric plug going into it. This maybe faulty.Mine was on my RR classic. As a temp. measure you can fit a manually adjustable mixer in its place (as fitted to carb, models) and set it up to your own optimum setting which if i remember is revving upto about 2000 rpm and adjusting the knob get a nice mix. This will also prove if it is the stepper that is at fault. bob
 
Slowly it all becomes clear. It would apear from the lack of servo adjuster that this conversion is not compleat. So where can i get a servo valve and can i fit it myself?
 
When you say servo adjuster motor , i assume you mean stepper motor. You must see if there is a multi plug lying in the area .If there is then you need the make of the system to obtain a compatible stepper motor , which can be found on ebay and other internet suppliers , or by calling in to your local lpg service centre. look at this ;LPG STEPPER MOTOR actuator for Autogas Conversion - NEW | eBay UK.
If there is no wiring/plug there, then you would have to have one installed, which may mean a new lpg control box and associated electric components. Around the fuel injection rail on top of the inlet manifold you should see extra plugs on top of the fuel injectors which go back to the emulators , which over-ride the efi side of things whilst on lpg. If you can't see any emulators or wiring leading to extra plugs on top of the fuel injectors , then you have an earlier open loop system which is really for carb. models.
So , you need to identify your system to make sure it is a closed loop system with emulators and lpg ecu and stepper motor. once you know what system you have , then you can proceed with your problem.
Checkout this site; Go LPG - Which type of LPG conversion do you need?
 
what crap....

You dont have to have a stepper motor just because you have efi.

If you have a lambda controled gas system you will have a stepper motor if you dont then you wont!! It has nothing to do with efi.

have a look at Carb-LPG Installation
 
I'm with EeEK on this in terms of the facts (but not necessarily the tone of the delivery)!

The OP has already posted it has three screw on the unit and one on the pipe so we know he has an open loop system with a manual power valve.

Nothing wrong with that, in fact many people believe that in a Rover V8, closed loop is the 'spawn of satan' :D
 
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