3.9 v8 lpg poor idle

hi all
v8, when on petrol runs badly and wants to stall but runs ok with "AIR FILTER" removed -runs on gas ok whatever ,what is wrong ??????? ALSO is it common for cylinder heads to leak a little by a little a mean a few drips about 1 or 2 inch on road, Motor starts on the key and doesn't smoke there is no cross contamination of oil or coolant and temperature is normal just hope i haven,t bought a lemon please put my mind at rest
V8 VIRGIN

whats it leaking oil or water? normally it would be the rocker cover gaskets leaking oil which is an easy fix.

whats the air filter like? blocked?

leak is definatly water and is definatly coming from head gasket and is just a small seapage might be worth re-torquing head up ???. Air filter does wont changing but thought would still run ok, have seen worse
many thanks

Could well be that the car has been tuned to run on Gas, timing etc.. The answer is simple - run on Gas!

Mine does not leak any water from the head so I am sure it is not normal. I would be very surprised if tightening it up would do it. Strongly recommend that you replace the head gasket on that side, if there is no contamination then quite likely it is only the gasket, leave it alone and problems could arise.

Don't think about it in terms of a lemon - you are now in a group of people that consider working on cars as normal as filling them up with fuel - enjoy it!

Hope you enjoy your new wagon.

robrennie said:

Could well be that the car has been tuned to run on Gas, timing etc.. The answer is simple - run on Gas!

Mine does not leak any water from the head so I am sure it is not normal. I would be very surprised if tightening it up would do it. Strongly recommend that you replace the head gasket on that side, if there is no contamination then quite likely it is only the gasket, leave it alone and problems could arise.

Don't think about it in terms of a lemon - you are now in a group of people that consider working on cars as normal as filling them up with fuel - enjoy it!

Hope you enjoy your new wagon.

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I agree with all that!

Need to run it on petrol to get it warm before going ongas then ok as for head gasket how big and long a job is it and are you best doing both

Have you had a check in the area of the valley gasket? It might not be head gasket, water leak could be where the valley gasket joins the head. If head gasket, a compression test should help to confirm.

The running with air filter removed but stalling with it in place suggests choked up air filter. If that is the case it may well be the engine is in need of a good service so plugs, rotor arm, dizzy cap, rocker breathers, air and oil filters. Check your ignition timing, see where it has been put I can't remember if it is advanced or retarded to run on gas. It might also be worth checking the vac advance and the mechanical advance are both working properly.

The fact it will run without air filter is encouraging but I think I might suggest checking the set up for the air flow meter.

Hope that helps; good luck.

BTW to do head gaskets, if you have all the parts and are reasonably proficient should be easily doable in a weekend. Remember do not rush it, so start strip down on a friday evening, finish strip on Saturday. Clean everything, make sure the plenum, ram housing and throttle disc are all clean, if the air filter is choked I'll bet the plenum is gonna be nasty!! As said before, check the vac advance on the dizzy and also the mechanical advance they need to be working.

Think will give it a good service then get compression test done,if it is gasket is it better to do them both .
Any one have service manual going cheap.
Cheers for all advice guys

BTW, waiting for the engine to be warm is a bit of an old wives tale. I run mine pretty much only on Gas. What I find in the winter is that it can cough a bit until it gets warm, otherwise its good.

Even in the summer it can be a pain if you start it and drive straight away, if you wait 30 seconds or so, its just fine.

Hi i had a very similar problem after an age got to the bottom of it air flow sensor try unplugging it run for a day if it stops messing around that’s the prob.
Mine is still unplugged cornt afford a new one but ace on lpg now hope this helps

try ebay for cheap haynes manuals with oily fingerprints

robrennie said:

BTW, waiting for the engine to be warm is a bit of an old wives tale. I run mine pretty much only on Gas. What I find in the winter is that it can cough a bit until it gets warm, otherwise its good.

Even in the summer it can be a pain if you start it and drive straight away, if you wait 30 seconds or so, its just fine.

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yes switch over when temp gauge starts moving

fitted new air filter today runs spot on, plugs next

good good!

a very good land rover v8 knowledgable mechanic mate of mine has just said that if running ok while on gas to leave well alone,gas being more likely to falter. the motor being set up for gas (10deg advanced)will cause poor running when on petrol

v6mon said:

a very good land rover v8 knowledgable mechanic mate of mine has just said that if running ok while on gas to leave well alone,gas being more likely to falter. the motor being set up for gas (10deg advanced)will cause poor running when on petrol

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Mmmmmm........... possibly? I guess if it runs let it be.