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Discussion Starter #1
Something weird is happening to my GTV

Going home last night I noticed the car didn't feel as sprightly as it had. A couple of acceleration tests on the motorway confirmed it. It now feels as fast as my MX-5, whereas before it felt as fast my Mrs' 330i. So it's not in a limp-home mode but it definitely feels like 50 or so horses have gone wandering off.

As you know, I run LPG so I tried switching that off to see if running on U/L made any difference. Nope. So unless I have a duff batch of LPG and the petrol's gone off, it can't be that.

Checked the oil - a little low (ooops) but not below minimum and I've now topped it up. No difference. Likewise I'm not running any flat tyres!

Weirdly, when I refuled last night, I did the calcs and the MPG has gone up to 30, it normally hovers around 25-26.

Maybe I've found an 'eco mode' on the V6 - all you have to do is press accelerator twice, brake four times, indicator on and off and then hit the accelerator again and hey presto!

God know how you turn it off though :)

Any ideas?

I want my Gee-gee's back! Here gg Gee Gee
 

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Discussion Starter #4
OK found this and will give it a go tomorrow.....

Originally Posted by CrispDust
Here's what I've used over past 5 years of Alfa V6 ownership:
Disconnect battery - short red to black leads (not the battery) - discharges and residual charge/cmos - saves waiting 45 mins or more.
Reconnect.
Turn ignition to MAR ie on but not engine start - leave for at least 90 secs while Throttle body sorts itself out. Turn off, leave for another 90 secs or so.
Fire up engine and leave idle without touching throttle until engine reaches at least 90 deg ie until fan comes on.
Turn off. Restart and drive it like it was meant to be driven.
 

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How do you work out your MPG with LPG?

I have got a duff tank of LPG in this time around, seriously sluggish on LPG, normally it's pretty good. You can actually feel the accelaration when the petrol injectors take over!

Not sure how the quality control with the gas works...
 

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Well there's 2 difficulties measuring mpg with LPG:
1. the car warms up for a mile or so on petrol, so this affects your mpg depending on how many cold starts you make on a tank
2. you can't "brim" the tank like you can with petrol - the gas pressure varies from one pump to another - sometimes I get 50 litres in, sometimes I only get 40... (60 litre tank)

You can get a reasonable estimate, but not as accurately as with petrol. Taking an average over 1000 miles works better.
 

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Well there's 2 difficulties measuring mpg with LPG:
1. the car warms up for a mile or so on petrol, so this affects your mpg depending on how many cold starts you make on a tank
2. you can't "brim" the tank like you can with petrol - the gas pressure varies from one pump to another - sometimes I get 50 litres in, sometimes I only get 40... (60 litre tank)

You can get a reasonable estimate, but not as accurately as with petrol. Taking an average over 1000 miles works better.
I guess there are just too many variables to get an accurate figure.. Turtle have you had a similar experience with LPG??
 

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Well there's 2 difficulties measuring mpg with LPG:
1. the car warms up for a mile or so on petrol, so this affects your mpg depending on how many cold starts you make on a tank
2. you can't "brim" the tank like you can with petrol - the gas pressure varies from one pump to another - sometimes I get 50 litres in, sometimes I only get 40... (60 litre tank)

You can get a reasonable estimate, but not as accurately as with petrol. Taking an average over 1000 miles works better.
1. You should be able to go on gas as soon as the car has started, just 'blip' the throttle after a couple of seconds from starting. If you can't do this then the LPG system probably needs servicing.

2.Run the gas empty, 'fill' with gas, run to empty again & calculate as normal.

The system only starts on petrol to keep the petrol system operative, otherwise after a long spell of running solely on gas it may not work.

I've currently got a Mitsubishi L200 V6 3.0 24v on gas & had many vehicles in the past from a Smart car to V8 Range Rovers & Jeeps.

Clive
 

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Thats a point if you are constantly changing fuel type, how does the ECU cope? excuse my ignorance I know nothing about LPG..
As far as I know the ECU doesn't know, isn't told & can't tell what fuel is being used.

Maybe in factory fitted cars this is different but it shouldn't really matter...I think.

If the 'burn' rate was that much of a difference then all cars being converted would have to be remapped,IMO.

EDIT: Although I was recently told that LPG needs a strong spark, where it might only slightly misfire on petrol on LPG it really 'hiccoughs'........enough to set fire to the air filter in my L200! Now fully sorted with a new set of Iridium plugs & a new vaporisor costing £500.

Clive
 

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1. You should be able to go on gas as soon as the car has started, just 'blip' the throttle after a couple fo seconds from starting. If you can't do this then the LPG system probably needs servicing.

Clive
This works when the engine is warm, but when cold it needs a few minutes to warm up - I think it's normal for my system and has been like this since it was installed.

Did you find the ECU reset helped GTVGent?
 

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It should switch to LPG as soon as the engine gets warm. It's usually at 40ºC. Old LPG systems switch immediately, not the multi-point injection types.
On some systems the engine has to be revved past 2000 rpm.
 

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Useful LPG info

Do I have to start my car on Petrol?

Having just fitted a new vaporisor to the L200, from now on I'll be warming it up on petrol before manually switching to gas, not letting the Auto setting switch it as soon as I blip the throttle.

Best to calculate accurate mpg on dry days in the heat of the summer.:lol:

Still at least it's cheaper....until the government raises the tax!

Clive
 

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Discussion Starter #17
Interesting comments re warming up on LPG - I always find it takes to about 55 on the temp guage before the LPG kicks in - normally about 2 or so miles into my journey.

I usually use the same garage for filling up (bargain too - 65.9p/l) so it should be the same pressure allowed each time; makes the mpg calc a little more accurate but you're right - it's not as simple as on petrol.

Working from home today so will test out the ECU reset affect tomorrow hopefully........

Will keep you posted
 

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It won't switch to gas until the engine reaches temperature. The engine coolant flows through an evaporator(vapouriser) that warms the LPG to ensure the liquid gas has been fully turned to vapour before allowing the LPG to cut in.
 

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Discussion Starter #19
Well, this is embarrassing, but I've found the cure to the lack of urge.

Didn't need the ECU reset after all, just moved the carpet mat out from under the accelerator pedal and all the power came flooding back.....doh!

Feel pretty stupid but at least it was a cheap and quick fix.
 
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