mot failure

fielden1981 · Posted: Fri Feb 26, 2010 4:21 pm Post subject: mot failure

hi wasnt sure where to post this as lpg may or may not be the problem so here we go

ive just took my lpg cherokee which is leaking gas so it went for the mot running on petrol and it failed on co2 emissions.
the jeep runs better on gas, now ive gust called the local lpg centre about the leak and the emissions

leak was: go round with water down fairy liquid squrting the pipes

emissions was: he is saying the needs to run good on petrol or it wont run good on gas

not sure what to about emission ive never had a problem with emissions

thanks for any input givin appreciate it

fielden

Ray_Jnr · Posted: Fri Feb 26, 2010 5:16 pm Post subject:

i have seen so many people running v8,s that run **** on petrol and theres no way it would pass an mot on emissions, however they have fitted lpg and just make sure its running on the gas when they put it in for the mot. emissions will be well bellow what they need to be on lpg

fielden1981 · Posted: Mon Mar 01, 2010 5:19 pm Post subject:

but the problem i have it that the mot tester knows it leaking gas and will fail the jeep if i test it on gas so it has to be done on petrol but i stll not sure how to bring the co2 emissions down
also its a 4L in line 6 and the lpg system is tartarini tec 97

Rossko · Articulating Joined: 23 Jan 2007 Odometer: 757

Well if you won't fix the gas leak, you'll have to fix the petrol side.
Does the oxygen sensor work? It's a favourite cause of emissions failures.
Have you driven it round for an hour on petrol before testing? If you've been running it on gas until the last moment, the petrol system may adopt a stupid fuel trim value and need time to recover.

seriesdriver · Guest

fielden

Sounds like you need to narrow down the leak location. Does it leak when running on gas or when system is shut down?
Is it single point or multipoint?
Is it just a whiff of gas under the bonnet when you switch off or have you got a gusher?

spannerman69 · Posted: Mon Mar 01, 2010 10:55 pm Post subject:

a friend of mine fits tartarini for a living i`ll pm you his number.he`s also a pretty good mechanic ,might worth while giving him a call and having a chat.

Ray_Jnr · Posted: Sat Mar 06, 2010 9:33 pm Post subject:

it seriously cant be that hard to find a gas leak, just go around your truck with a lighter Laughing

on a serious note, get some soapy water and go round all the joints, youll soon see the problem.

Joinerman · Articulating Joined: 18 Jan 2008 Odometer: 606

Turn it to petrol & take it for a blast up the m/way for an hour, drive it like you stole it, do this just before the mot, should sail through after a good clear out.

fielden1981 · Posted: Tue Mar 09, 2010 6:54 pm Post subject:

well i took it for a good run before the mot its was nice and warm but still failed on co2 emisions, it pinks sometimes not sure if it is the cat or wether it needs plugs leads and a dizzy
ive been told if it does not run well on petrol it wont run well on gas that is why i am trying to get it running well on petrol

as for the gas i can only smell it when it is running lumpy with lack of power and spits back to the air , the air box has a hole in it that i fixed dont know if this is related or not

im not sure if it is leaking or if it is running wrong which is making it leak gas

i just dont know where to start with it Evil or Very Mad

treeboa · Posted: Tue Mar 09, 2010 7:54 pm Post subject:

leads n decent plugs for what they cost have to be considered, as does getting the timing checked if its `pinking`

Rossko · Articulating Joined: 23 Jan 2007 Odometer: 757

fielden1981 · Posted: Wed Mar 10, 2010 1:07 pm Post subject:

so where do i find the oxygen sencer and how do i test it Question

fielden1981 · Posted: Wed Mar 10, 2010 5:51 pm Post subject:

just took the cat off as my friend told me the co2 sensor is the same as the lambra sensor and the cat is hollow so im thinking this is why its running like a bag of spanners, would the co2 sensor be able to work properly with the cat being shaged and could this be the reason why it is back firing into the airbox and smelling of gas

Rossko · Articulating Joined: 23 Jan 2007 Odometer: 757

http://www.google.co.uk/search?hl=en&source...ng+oxygen+sensors

If the sensor is broke, and has been broke a long time, it can contribute to cat failure ; but not usually the other way round.

jonny jeep · Posted: Thu Mar 18, 2010 12:12 pm Post subject:

If the cat is hollowed out that's your first problem. The cat is there to reduce emissions. Replace it.

There are two O2 sensors on a 97. One before the cat. One after. The pre cat sensor is used to work out your fuel ratio. The after cat sensor is there to tell the computer if the cat is working properly.

Typical expected sensor life is 100k miles. As it's a 97 you might as well replace both sensors when you fit a new cat.