Vs has backfire and idle problems

[Blackvs96]

Like i said solved the bad idling problem, connected the small hose i was talking about and since then it idles at lights on gas so smooth, but still backfires when i hit the gas hard. Any ideas or should i just figure it out myself.

Reason i ask for help is I'm single mum and don't want probs with my 3 month old bub in d car, looks like ill have to get the problem figured out myself , will keep u informed when i find the main problem with this backfire issue by spending a lot more money then i can offered to rectify the main problem,

I just thought all you nice ppl mite know the actual cause of the problem.

Error 35 came up if that helps.

Thanks again

 

[DAKSTER]

I don't want to be a pill here, you are talking to people who obviously know what they are talking about. I can't help feeling though, I see so many threads where people have replaced half an engine looking for a problem, that sometimes it would be better to spend a little to make sure you don't waste a lot.

Gas needs regular servicing, how long since you have had a gas service? A basic gas system service is about $80 where I live. Its probably not much more than an inspection, a few adjustments and a few O rings or something, I dont know, but I have had gas running badly when I took it for a service and running well when I got it back.

I know they had it on all kinds of equipment while it was there, it seems likely to me that they would either fix it as part of the standard service, or at least be able to diagnose it correctly so you buy the right parts instead of chasing your tail. If its just a sensor or leads or something it probably would only cost the price of the parts on top of the service cost, and of course the service won't be wasted money in any case.

It seems to me that someone with diagnostic tools and their hands on the car has a much better chance of correctly identifying what could be a choice of multiple possibilities than the undeniably knowledgable people in here, who unfortunately don't have the advantage of having the car and diagnostic tools in front of them . I understand that $80 might be a lot to you, but if you start buying parts and none of them make a difference, you won't take long to have spent a lot more than that.

I'd be taking it to a reputable gas guy and having a standard service done on it. If it needs more, at least he should be able to tell you exactly what that is, rather than you pouring money into it looking for the problem. If its something simple, you shouldn't even have to pay extra labour.

DIY is a good thing, but sometimes its cheaper to take it to an expert.

 

[Blackvs96]

I've been reading through a few threads bout LPG and i came to now realise that my vs doesn't come with a mixer, my air intake pipe is standard to a petrol run air intake pipe.
There's no round silver round mixer in between the pipe.

There is a regulator which is in the far right corner, so is this the reason why I'm getting back fire?

I've got pics but just can't post them up cos i don't have a comp only got iPhone.

 

[Blackvs96]

These are the pics of the hose i was talking bout that joined to the back of the top manifold, which i decided to connect, but i haven't got a mixer as u can see in the pic.

What should I do, regards to all my questions

 

[Blackvs96]

These are the pics of the hose i was talking bout that joined to the back of the top manifold, which i decided to connect, but i haven't got a mixer as u can see in the pic.

What should I do, regards to all my questions

If u need more pics let me know if its helpfull.

 

[Blackvs96]

K so I've refitted the air hose i was talking about that was clamped shut. It did stop the rough idling on gas but on petrol it idles still ruff.

So I thought I'd weight till petrol went on empty and filled bout $10 of vortex petrol at caltex, I think it's vortex but anyways I poured the most expensive fuel.

Drove for abit till it went close to empty again and added a bottle of injector cleaner and filled it full of the expensive petrol.

During those times I've been making sure i start the car when cold on petrol and then switch to gas.

I gave the gas system a nice flooring and it didnt back fire till, I hit the foot hard down pedal to the metal and it back fired.

So I have to say the idling is perfect now on gas and petrol,but still back fires on gas.

So I've gone and got 0.8mm leads and coil pack, dfi module. Haven't fitted it yet because I'm gonna wait till I get the plugs.

I got all them parts from the pick a part wreckers and chose to pick the parts off the car that was running on gas. Tomorow I'm gonna head back and start looking for spark plugs that looks in good nick before the accident.

Hopefully replacing all these parts will stop the back fire.

 

[Blackvs96]

From memory sprintgas is very similar to Impco. (Sprintgas is Australian and Impco is American) Have a look on the mixer (this will be in the inlet tract and will have a thick rubber pipe joined to it) On the mixer there should be an adjustment knob, usually a circle with 2 flats machined in it for a spanner to suit (fom memory it's a 9/16). Look very closely at this adjuster and you should see the letters L and R with a number of graduations in between.

This is the gas mixture adjuster. The letters are for Lean and Rich. Check where the pointer is on yours and try going one notch richer. Only move one notch at a time and give it a few days between adjustments. This is to allow for cold starts, hot starts, and all types of driving. The backfiring through the airbox and other problems you mention can be caused by an overly lean mixture.

As others have rightly said, your entire ignition system needs to be spot on. Gas is harder to ignite than petrol and puts a lot more load on the ignition.

I had the owner at the wreckers have a look at my gas system and he spotted the regulator at the far right top corner when you face in front of the car, he said that i didnt have a round mixer between the air intake pipe because my system wasnt impco.

He said the regulator I got is a very good one, got no idea why but anyways he manage to find the adjustment knob problem is, is that it's tucked behind next to the fire wall.
It's got 2 adjustment knobs, 1 for air and the other for lean & rich.

Problem is its tucked away all the way behind the regulator in a tight spot, so I can't see no wording, between the knob it's got spring holding it and I can just adjust it by hand.

My main question is which way do I turn. Should I just start the car and turn it bit by bit until the backfiring stops, also I don't know which one to adjust, the air or the gas mixture, because someone mention below that they had there car back firing because too much air was coming in.

Please help really hope someone has some helpfull ideas for me because that would be so good.

Will be hanging to looking forward to someone's next reply.

Regards

Blackvs96

 

[Blackvs96]

Ok so I'm slowly getting there, I've found the adjustment, there's one big screw and one small screw.

1 of it is for leaning or richening the gas & 1 is for air, but I don't know which one is which.

Yesti I had the car running on neutral and started adjusting the screw the 1st screw I adjusted would make the idle rough n then turn the other way and it would smooth the idle. So is that screw is gas or air?

The o ther screw I adjusted really didnt do much when turning, so which one is that gas or air.

Since the screw is behind the regulator I can't find the rich n lean sides, the screw I mention when I turn it and it goes rough dies that mean its getting in to much air.

If someone can help me with some advise on adjusting it that would be very good because I'm now pretty 90% that its just a matter of me adjusting the mixture right.

Looking forward in seeing all your replays

Thanks you all in advance

 

[Maxmadmat]

Use a mirror to see the mixture markings.

 

[Cheap6]

For your reference (and ours) what you have, at least as far as I can tell from the pics., is an OMVL system. As a check, there should be cast into the part of the converter that faces towards the centre of the car "OMVL R90E". In any case, the metering of the LPG is done by that unit, although there may be some correction in between that and the mixer in addition.

v8Dualfuel.com: LPG / Autogas conversions and Kits for the Rover V8 Engine ???

boost reference help - fullBOOST ???

Those two adjustments on the converter are both for mixture control. The screw without the spring around it is for when the engine is at steady throttle or accelerating and the other one is "sensitivity". Sensitivity controls when the converter switches from an idle mixture on acceleration and back again on deceleration. You should have marked where the screws were before you started - paint or nail polish is good - so you can put them back to where you started from if it doesn't work.

This should help:

How To: How To Tune Your LPG system at home - www.fordmods.com

On a Commodore, don't bother with the feeler gauge but run the car on petrol and disconnect the Idle Air Control valve wiring connector then switch to gas. The IAC valve is the black cylinder on top of the inlet manifold. That does the same thing as using the feeler gauge; it stops the engine computer from altering the idle speed while you make the adjustments.

So you can understand what you are doing: Converter OMVL R90/E Parts under the Diaphragm

I'd be looking at the join between the mixer too (yes, you do have a mixer; that is what is known as a "simple mixer" - basically a tube with a smaller diameter restriction in it to draw the LPG into it) and the throttle body. All I can see that is forming the join is a wrap of electrical tape. Correct? If that join is leaking it will suck in air and cause a lean air:fuel mixture (low in fuel). That could be part of your problem.

There should be a very short length of rubber hose and a couple of hose clamps across that join. You may have to source the hose from an LPG workshop but you might try somewhere like Pirtek or Enzed if you explain that it has to be fuel resistant. It's possible that someone has left that hose off to avoid any damage if there is a backfire.

For reference:

http://www.fesautogas.co.uk/r90eservice.pdf (14Mb - you might not want to use a phone for this. It's a service manual for the R90E.)