Gas Mileage - is it good, bad or do I have a problem?

[David48]

Gas Mileage - is it good, bad or do I have a problem?

I bought an old car from a Forum member here.

Same(ish) model - A Seat -Cordoba

Essentially a VW Polo, undercarriage, suspension and Engine from what I can gather and the Spanish Company SEAT stuck a slightly over-sized body on it. 4 cly, SOHC and maybe 1600cc?

A previous owner converted it to Petrol/Gas ... the Gas being LPG.

It has a tiny Gas tank ... maybe 30 liters (it's a small boot!)

I drive mainy low speed country highway (Old Sukhumvit road) and a little bit of City driving.

It did 96 kilometers on 22 litres of gas.

That Gas Mileage - is it good, bad or do I have a problem?

Anyone with the smarts to covert it for me into miles per (UK) Gallon, or something else relevant?

If it is cr*ap ... what are common causes for poor Gas Milage?

We have changed the Motor and Gear oil and filter. I have checked the air filter and it's OK ... haven't cracked a spark plug yet though.

Over to you guys.

Thanks in advance for the replies ...

.

[WarpSpeed]

I can't do the conversion either at the mo but sounds low. How well does it run? I owned and sold several of those over the years there and they are nice little cars, all of them Lp conversions but none with a tank that small, it does have a small trunk but we managed with it ok even with a larger tank though i did upgrade the rear shocks to handle the extra weight and never filled both tanks at the same time and only filled the petrol tank about 3/4 full.

Until I know how it's running it's kind of hard to tell. and I'm not sure how well to determine it's operation? What type of system is it? Does it inject into the air intake tube or does it have multipoint? How much mileage does it have on it? It may need a timing belt, if the one you have is stretched it will be off time and give poor mileage and power loss undetectable until you change the belt and realize how much better it is. Plugs and then timing, also must use the highest petrol octane you can get, preferably not gasohol if it's still available or where you're located, it helps to keep the top end lubed and cooled which prevents the engine to tightening up when it gets hot after running a long time this uses more Lp. Without more info this is the best I can do at the mo.

[ToddWeston]

96 kilometres = 59.6 Miles

22 litres = 4.8 Imperial Gallons

12 mpg

[Jessi]

To compare my 96 Corolla I filled yesterday

28.47L....LPG....divide by 4.55 to get the gallons

272Klm. X by .6 to get the miles.

= 26.08 MPG

and my car needs a tune up, the plugs have done over 30,000K

[David48]

Seems that my fuel economy sucks then.

Where to start to analyse the problem?

The petrol tack is a 1/4 full and I bought the higher grade octane as the petrol hardly gets used except at start-up.

I'll go get the Gas system details today.

I'm really interested in hearing solutions to the problem, however, if I'm absent for a day or two from my thread ... I recently had TWIN boys and they keep me more then well occupied!

[David48]

I can't do the conversion either at the mo but sounds low. How well does it run? I owned and sold several of those over the years there and they are nice little cars, all of them Lp conversions but none with a tank that small, it does have a small trunk but we managed with it ok even with a larger tank though i did upgrade the rear shocks to handle the extra weight and never filled both tanks at the same time and only filled the petrol tank about 3/4 full.

Until I know how it's running it's kind of hard to tell. and I'm not sure how well to determine it's operation? What type of system is it? Does it inject into the air intake tube or does it have multipoint? How much mileage does it have on it? It may need a timing belt, if the one you have is stretched it will be off time and give poor mileage and power loss undetectable until you change the belt and realize how much better it is. Plugs and then timing, also must use the highest petrol octane you can get, preferably not gasohol if it's still available or where you're located, it helps to keep the top end lubed and cooled which prevents the engine to tightening up when it gets hot after running a long time this uses more Lp. Without more info this is the best I can do at the mo.

Thanks for the reply ... I'll come back with more details soon.

[bkkjames]

96 kilometres = 59.6 Miles

22 litres = 4.8 Imperial Gallons

12 mpg

with his tank only 30 liters, i guess he can fill it with enough to get to the next gas station.

[VocalNeal]

If you did 96km on 22l of LPG then it is a bit low you should be getting at least 160+km from 22l. That figure is based on the mileage from a pickup so in reality you should get more than that.

Where are you? You need to find a mechanic who works a lot on taxis to clean and tune your LPG system or take it to a local LPG installer and get the same thing done.

If near BKK I can point you in a direction.

Spark plugs used on LPG cars only last about 10,000 kms. There are "special" ones but not economically worth it. If you can get one range colder as LPG runs hotter I.e. if NGK 6 is specified for the car you need to try and find a 7 ( not life and death) and set the gap a little less.

http://www.ngk.com.au/spark-plugs/technical-information/lpg-compatibility

PS You have confused all the colonials with gas vs. what here we call benzene.

Edited April 7, 2014 by VocalNeal

[seedy]

Start with a good basic tune-up. New spark plugs, spark plug wires, distributor cap and rotor.

Have the ignition timing set to factory specs. Not a bad idea to replace O2 sensor as that is what the computer uses to determine injector pulse width i.e. how long the fuel injectors stay open i.e. how much fuel to inject.

When this is done, then you have a baseline and know that these wear parts are not the problem.

Check for vacuum leaks. Remove all connectors from engine sensors, clean and replace.

Check OBD2 for trouble codes.

Perform wet and dry compression check.

All these steps, if performed by a knowledgeable person, will point out where the fault lies. Usually !!!

Edited April 7, 2014 by seedy

[WarpSpeed]

Seems that my fuel economy sucks then.

Where to start to analyse the problem?

The petrol tack is a 1/4 full and I bought the higher grade octane as the petrol hardly gets used except at start-up.

I'll go get the Gas system details today.

I'm really interested in hearing solutions to the problem, however, if I'm absent for a day or two from my thread ... I recently had TWIN boys and they keep me more then well occupied!

Ok, you should be using your petrol more then that, you need to run it through regularly so it can lubricate and cool your valves and cycle out the gas before it gets too old. On long trips of an hour or more I used to run the petrol 15 minutes for every hour of Lp run time, run petrol about 10 minutes before shut down to cool and lubricate and restart with petrol until warmed up at least.

[transam]

To have that poor fuel consumption fuel is being dumped in, you will need to go to a garage to find out where the problem is. As suggested, a taxi place sounds good.

[MBChai]

Firstly check the injection or fuel pump ..parameters differ ..else remove the spark plugs and look for any carbon deposits..

[petermik]

Seems that my fuel economy sucks then.

Where to start to analyse the problem?

The petrol tack is a 1/4 full and I bought the higher grade octane as the petrol hardly gets used except at start-up.

I'll go get the Gas system details today.

I'm really interested in hearing solutions to the problem, however, if I'm absent for a day or two from my thread ... I recently had TWIN boys and they keep me more then well occupied!

David-Congratulations on the "twins" first time I,ve ever heard of a bloke actually giving birth-painfull labour?

[David48]

^^ ... it's all good ...

[David48]

I have some engine/gas thingie photos and will compress them and upload then as soon as time permits.

Thanks for all the replies thus far.

It's nice to be amongst knowledgeable motoring enthusiasts.

[BSJ]

Do yourself a favour and get a gas mechanic to have a look at it. Sure it maybe plugs and ignition leads, but there would also be hard starting issues if that was the case.

[Jerry Cornelius]

Less tha 5km/l is definitely not good with an average car.

Does it run in any gear other than first?

Jerry

[WarpSpeed]

I have some engine/gas thingie photos and will compress them and upload then as soon as time permits.

Thanks for all the replies thus far.

It's nice to be amongst knowledgeable motoring enthusiasts.

Who said anything about knowledgeable? You're too kind....

Seriously though also congrats on twins.. Also are we talking about both fuels? Presumably we're only talking about the Lp correct?

[JAS21]

Try this for converting ... http://www.thecalculatorsite.com/conversions/fuelconsumption.php

You could do a test just on petrol .... full tank to full tank (you don't need to use a full tank to get a rough check but maybe fill both times from the same pump and when the pump cuts off say STOP, ... that way you should be able to tell if its the engine or the LPG system. I assume that you watched carefully that the LPG filling station reset their gauge before filling your car and that you actually paid for the right pump! You wouldn't be the first ....

I would have expected around 10Km/Ltr ... towards 25mpg on that vehicle if you were just pottering around. However in heavy traffic it could be somewhat less.

Have you asked the previous owner what consumption he got?

[WarpSpeed]

I'm concerned the valves may have gotten burned and you're losing compression, but until I got more info. it's hard to say. Does it run rough?

[David48]

Have you asked the previous owner what consumption he got?

Thanks for the Conversion thingie.

As for the previous owner ... Pattaya Dingo ... I have the story that he is back in the UK with health conditions.

I did a thread in the Pattaya forum asking if anyone knew him ... apparently a Ghost with over a 1,000 posts.

I'm the trusting type ... but I got nipped (bitten) with the car!

[David48]

OK ... the updates as the TWINS and Mum are asleep, and I'm on my 3rd well earned drink!

the Beast

Gas control

I looked up the 'technic auto gas atx-4' ... tis all in Thai ...

Engine bay with the gas control valve circled in red.

gas control valve.

Now the mechanically minded Farm Father has turned down the pressure with that valve adjustment.

which is great, because I filled the gas tank just after (I didn't know) and reset the trip meter ...

So, I'll run the tank down and then report back.

I have an open mind to the answer, so please don't hesitate to reply.

Oh ... me, MissFarmGirl (a member here) and the boys ...

[seedy]

Beautiful Family !!

Be Proud !!

Good luck with the car. too.

[ignis]

asked a friend, he says on petrol the old Seat Cordoba should get between 32 to 37 MPG.. UK gallons

What about testing it using petrol only ?

Remember years ago they did a test on the then new Ibiza [the Cordoba is the boated version] they got on a economy test drive was the best MPG on this size of car for the year think about 1996..

[VocalNeal]

P4070380 LR RR.JPG

Engine bay with the gas control valve circled in red.

.

Looks like a standard taxi open loop system. So any mechanic who routinely works on taxis will know how to set it up.

[WarpSpeed]

I vaguely remember Dingo posting a thread here about something similar initially poor gas mileage but it went along with an Lp gas smell. I did a search but it seems Dingo is no longer a member and I can't find his thread. He had located a leak if memory serves it was something minor maybe a fill valve, but can't be certain it was some time ago. But check to see if you smell gas around the car especially towards the back.. Maybe someone here can also recall now with a reminder and or find the thread I can't find, but with new little ones check thoroughly for this..

[Ace of Pop]

My Friend is a Gas Fan,and his answer to the Question.. If its over 1Bht a K.M get it checked. Yes he is a Farmer .Car 6.Y.O Camry. Highly Tecnical Reply

[WarpSpeed]

BTW I hope you have an idea how much you adjusted that gas valve, as once adjusted they don't really require more adjustment. It may now throw off the rest of the tune and cause you even more problems hunting down the real issue.. The evaporator might need cleaning out too, it's likely been some time since it was last done, not sure that would effect mileage a whole lot more likely cause running problems in Lp mode but it's necessary maintenance anyway..