Fuel Supply (gas) Issue

[GK]

Hi,

I've been having issues with my wagon at WOT applications. I had the leads changed yesterday and it was still hesistating (read going nowhere!) when the foot was put down.

I switched to petrol and had no such issues. I began thinking that it mustn't have been the plugs, leads or coilpack at all (coilpack not yet changed) but a gas metering issue.

Got home, rang gas mechanic to enquire and he said it was this issue. The fuel stepper motor and attached valve (adjustable) in the line between converter and intake needed to be opened. Here is a pic. It's labelled.
http://www.fordforums.com.au/showpos...6&postcount=55

So I opened it up a little a few turns and there was improvent. Still hesitating though, opened more, better, bit more, bit better and so on.

Here's the question though. Do I simply keep going until there is no hesitation on the highway at WOT? This was my trial and error intention. Is there a point where I go too far?

Your help as always is greatly appreciated.

Cheers,

GK

[private9]

I don't know if this helps, but I had a very similar problem in my EF that I had an Impco conversion done on recently. Basically, whenever you planted it on gas, it would just hesitate and go nowhere, and then pickup after a few seconds. Didn't do it on petrol though.

Ended up being the rubber elbow/intake pipe straight off the throttle body sucking closed for a few seconds on full throttle. I did try swapping pipes etc, but I was never able to get it fixed, and to this day I don't know why it only did it on gas and not petrol.

[FGII-XR6]

have you had the gas filter done ? yes the have a filter just like petrol cars and if its geting blocked it will behave just like you describe

[GK]

Originally Posted by au3xr6

have you had the gas filter done ? yes the have a filter just like petrol cars and if its geting blocked it will behave just like you describe

Where is it located? What does it look like?

GK

[GK]

The converter was cleaned a few weeks ago and hardly had any wax in it.

I'll get it sorted, just a matter of time.

GK

[GK]

I've been adjusting the brass/bronze valve in the stepper motor, with some success, but today it was still hesitating.

I pulled it off when I got home from work, cleaned it out and adjusted it to about halfway.

This is what I'm thinking. The stepper motor supplies gas off idle and after that the computer takes over with the converter etc.

When you give it WOT though, this brass/bronze valve is what restricts the gasflow. Many models don't have this adjustable valve, but the stepper attached with hose; in essence a straight through pipe.






So why don't I open it up fully? Can anyone offer me some guidance here?

The silver bit inside the pipe is the valve/piston attached to the actual stepper motor.

Is there a point where I go too far? I asked this Q earlier today but didn't get any response on it.

Cheers all,

GK

[au2sw]

just a q, the actuator, do you have it pointing down, up or at a slight angle up from horizontal? the tar can clog the actuator up if its pointing down. best to have it just up from horizontal. have you got a fitter with a dyno close by? your best to go there and get it tuned properly then trying to do it the way you are. rev tuning works, but you will have the best results from a dyno tune. the brass flow restictor basically contrlos the amount of gas flowing to the engine, combined with the actuator. the further out you go, the more gas your going to use. more info can be found or asked for in the LPG forums futher down the main page.

[GK]

I've had a look at the gas forum before, but answers come very slow there. I know more people will see my thread here in good old AU land! There are many of us gas lovers here.

I appreciate your comments.

GK

[The Dok]

Sounds like the same problem I had with mine quite a while ago George, I posted on a thread back then so I'll see if I can locate it & if so post a link, it should provide all the answers (my issue disappeared when I installed a flow control valve similar to yours, but I had to disconnect the stepper motor/power-valve).
Try this thread

[GK]

Originally Posted by The Dok

Sounds like the same problem I had with mine quite a while ago George, I posted on a thread back then so I'll see if I can locate it & if so post a link, it should provide all the answers (my issue disappeared when I installed a flow control valve similar to yours, but I had to disconnect the stepper motor/power-valve).
Try this thread

Hey Dok,

Further on in that thread I said this about the price of gas compared to petrol! Aaaaaahhhh 2 years ago, how things change! LOL!

Originally Posted by GK

Yeah AU98C-Wagon, I know how it is. In Melbourne it's roughly 34 compared with 98!

Now back to the topic. My issues are at wide open throttle. 2 years ago, the issues were with small throttle openings like you had. The replacement of the stepper motor fixed that up promptly.

I'm just trying to work out how far out to turn this screw! I guess the correct answer is until the full throttle issues go away?

I wonder if there could be an issue with the throttle position sensor?

GK

[The Dok]

When I installed my flow control valve, I was instructed to adjust it as you would an air/fuel mixture screw (carburettor type vehicle), mine has been sweet for over 2 years now. Give it a try, at worst, as has been stated, dyno it!

My only concern now is how long it takes Casper to hone in on this thread, you know what he's like when there's a sniff of LPG & talk of petrol prices in the air... lol

[GK]

Originally Posted by The Dok

When I installed my flow control valve, I was instructed to adjust it as you would an air/fuel mixture screw (carburettor type vehicle), mine has been sweet for over 2 years now. Give it a try, at worst, as has been stated, dyno it!

My only concern now is how long it takes Casper to hone in on this thread, you know what he's like when there's a sniff of LPG & talk of petrol prices in the air... lol

I reckon I'll just keep manually adjusting it to see if I can sort it out. I have a week of driving on the Keilor-Melton road to see what I can work out.

Dok, how did you work out how to adjust yours? Was it trial and error like what I'm attempting?

And sssssshhhhhhhh, if we keep this really quiet, Casper will never know! LOL!

Cheers (said in a quiet whisper!)

GK

[The Dok]

Yup, trial & error, it uses a pinch more fuel the way it is now (no stepper motor) but has noticeably more power.

As an example, 3 weeks ago I took it to Eildon, (through the Black Spur) with my bike trailer, 2x250cc bikes, 3 adults & a truckload of riding gear (it was dragging it's bum) & it cost me less than $35 return including 2 trips to Rubicon Valley, I recommend a drive through the Spur, that'll pretty much cover ALL throttle & gear positions & simulate almost all driving conditions lol.

[GK]

Originally Posted by The Dok

Yup, trial & error, it uses a pinch more fuel the way it is now (no stepper motor) but has noticeably more power.

As an example, 3 weeks ago I took it to Eildon, (through the Black Spur) with my bike trailer, 2x250cc bikes, 3 adults & a truckload of riding gear (it was dragging it's bum) & it cost me less than $35 return including 2 trips to Rubicon Valley, I recommend a drive through the Spur, that'll pretty much cover ALL throttle & gear positions & simulate almost all driving conditions lol.

Trial and error it is then. I don't suppose you could pull it off and tell me roughly how far wound in it is could you? Mine is only held on by 2 clamps and the electrical connector, but your setup could be more complicated. If it's any hassle don't worry about it. I've been opening it up bit by bit and I'll get there soon enough I suppose.

It'd make an interesting comparison though. I guess it depends which converter we're running and such.

I've wound it out to about half, cleaned and reinstalled it. I'll give it a good highway run on the way to my mum's for lunch on Sunday. That'll give me an idea of highway tuning and I can do a few fast take offs tomorrow around town I guess.

Cheers,

GK

[trick_xd]

Unplug the stepper motor and manual adjust it like you have been doing.

You could very well have it sorted right but the idle stepper motor takes a bit of time to react so you get that bit of throttle lag.

If it is closed to far you will rev and not go anywhere ..

If it is open to far you will rev and not go anywhere..

So keep turning it 1/2 at a time until you get no more power then turn it back 1/4 or 1/2 turn . If you do this on the same stretch of road and up a hill you should be able to set it very well all by your self

[GK]

Originally Posted by trick_xd

Unplug the stepper motor and manual adjust it like you have been doing.

You could very well have it sorted right but the idle stepper motor takes a bit of time to react so you get that bit of throttle lag.

If it is closed to far you will rev and not go anywhere ..

If it is open to far you will rev and not go anywhere..

So keep turning it 1/2 at a time until you get no more power then turn it back 1/4 or 1/2 turn . If you do this on the same stretch of road and up a hill you should be able to set it very well all by your self

So do the testing with the stepper motor unplugged then? Won't that mean it doesn't idle at all?

Also, with regards to what constitutes a full, half and quarter turn, am I right in assuming a full turn = one full revolution of the nut/dial/wheel? Or is a full turn one twist of the screwdriver. I think I prefer the full revolution, much more accurate to measure. In any case, I keep adjusting outwards until I slip off the performance edge, then go back slightly. That right?

As for the uphill stretch, I have just the road in mind!

You know, I may have already gone out too far, if so, I'll know soon enough. I'll just go back a number of turns and work outwards again!

Cheers,

GK

[trick_xd]

your best to work in 1/2 turns .. as 1 full turn is enough to really put you out of tune.

the idle stepper motor is a problem that they have.. So just unplug it and leave it unplugged and see how you go for a few days while you are sorting it out..

Cheers
Swanny

[GK]

Originally Posted by trick_xd

your best to work in 1/2 turns .. as 1 full turn is enough to really put you out of tune.

the idle stepper motor is a problem that they have.. So just unplug it and leave it unplugged and see how you go for a few days while you are sorting it out..

Cheers
Swanny

Thanks for that Swanny!

GK

[GK]

Ok the update.

I have a great stretch of quiet road with an uphill grade (near industrial estate) within 10 mins from home.

I knew that I had wound the brass screw too far out (rich) and therefore commenced a number of runs gradually winding the screw back in 1/2 a turn a go. I reckon I've got it pretty darn close and ended up going in 1/4 turns. I think I went too lean and set it back 1/4 towards richening it up again.

The last run had no starvation, and felt like it was revving cleanly all the way to redline through the gears. It wasn't pulling as hard as I'd like though and if I need to adjust it any, I'll go 1/4 richer and see how that goes. If performance gets worse, I'll know the 1/4 back to lean is the optimum.

I will drive it tonight to Upwey (helping out a good mate with his house) and see how it goes on some more hills!

I appreciate your help guys.

One more thing though, I couldn't do the above testing with the stepper deactivated. As soon as I did, the car drove like a pig.

Cheers,

GK

[trick_xd]

ok so if you unplug your stepper its some times the best way of setting the gas.
with it pluged back in it tell me that the computer is trying to control your gas all the time ... not just on idle like it is ment to. the only way around it now would be to take out the stepper motor and put in a manual power valve.

[GK]

Originally Posted by trick_xd

ok so if you unplug your stepper its some times the best way of setting the gas.
with it pluged back in it tell me that the computer is trying to control your gas all the time ... not just on idle like it is ment to. the only way around it now would be to take out the stepper motor and put in a manual power valve.

I guess I can test it again with the stepper unplugged as when It was driving like a pig, was before I began winding it back towards lean. I made a number of 1/2 turns (say 4-5) before it was getting into the zone.

I'll give it a go again tonight with it deactivated.

Many thanks for your help.

GK

[GK]

Car is very close to being right. It will start, idle and run fine now without the stepper motor connected.

Still not 100% though. I'll keep trying.

GK

[trick_xd]

Can you take a pic of your converter and a pic of your mixer .
what sort of gas kit is it ?
a pic of these and a over view pic might help

[private9]

Glad to see that you're nearly there George. You're such a tinkerer and an inspiration to those of us that have no idea!!!

[GK]

Originally Posted by trick_xd

Can you take a pic of your converter and a pic of your mixer .
what sort of gas kit is it ?
a pic of these and a over view pic might help

I'm out of light today but I will tomorrow.

The Mrs had a hesitation whilst driving to work this morning as she gunned it to hit the freeway. She must have given it pretty much the full stick as it only had a slight hesitation under full load!

I'll get those pics to you shortly.

Trick xd, are you thinking that the main jet in the converter/mixer may need a slight tweak?

I apppreciate having you along for the tuning ride!

GK

[GK]

Originally Posted by private9

Glad to see that you're nearly there George. You're such a tinkerer and an inspiration to those of us that have no idea!!!

I guess you have to try to learn along the way. But note this thread, I've had stacks of help from tick xd and the Dok.

That's what it's all about, helping each other and saving the hard earned moula if at all possible.

I appreciate your encouragement.

GK

[trick_xd]

yes .. if it is ok under power then it might just need a slight lift in idle .... it is ups the idle so it is smooth then it will help a stutter and your pulling power at revs.

[GK]

Did a stack of testing tonight.

Got it very close. I locked up the nut and will test it on the way to work.

What I did do which I've not done as yet, is draw vertical lines on both screws, gas mix and sensitivity so I could get them back to where they were if I've stuffed it. I moved the smaller one (the gas mix - which I understand is the idle) back and forth until I worked out which way was which, and I opened up the idle a fraction.

I also opened up the sensitivity screw a little (read a few mm).

I'll give it a run and see. If it's no good, I'll set the sensitivity screw back until the control line is vertical and leave the idle up.

We're slowly getting there! LOL!

I took those pics you wanted, but can't upload them to photobucket, as my internet speed has been limited and the photos would take hours to load.

If you PM me your email address I could email them to you when I get home from work.

Cheers,

GK

[The Dok]

I'm still watching this thread George, having reviewed the images, there are some distinctive differences in you set-up compared to mine, as I stated in my thread ages ago, I actually removed the (scored) plunger within the stepper motor (factory fitted Tickford system) & after some fine tuning, had it running better than ever. The cost of a new stepper motor ***'y was @$160 which I thought was ridiculous.
If your system still gives you grief, you could investigate replacing the stepper motor/powervalve set-up you have there with a simple in-line screw type adjuster.

[GK]

Originally Posted by The Dok

I'm still watching this thread George, having reviewed the images, there are some distinctive differences in you set-up compared to mine, as I stated in my thread ages ago, I actually removed the (scored) plunger within the stepper motor (factory fitted Tickford system) & after some fine tuning, had it running better than ever. The cost of a new stepper motor ***'y was @$160 which I thought was ridiculous.
If your system still gives you grief, you could investigate replacing the stepper motor/powervalve set-up you have there with a simple in-line screw type adjuster.

Dok, If I pulled the stepper plunger out, what would I use to fill up the space? I imagine the void left by it would fill up with gas?

I reckon it's worth a try though, as I'd reckon the plunger does have an effect on the flow. If it's gone, it's just down the the fine tuning of the in-line valve.

I wonder if a metal or plastic plate using the existing screw holes would do the trick?

GK