3.3 2006 Lpg Missfire On 1 And 3

[thedogss]

can anyone help me please I have a 2006 3.3 Chrysler which is showing a misfire on 1 and 3 it has LPG which was fitted 5 years ago ive owned it for about a year , so it started with the engine management light coming on and showing code po300,po301 and po303 so after looking up codes its misfiring on 1 and 3 so and change the plugs turns lights out and the same thing happens a few days later so now I change the leads and then same thing happens next I change the coil , same thing happens I then have the gas system serviced and again a few days later the same thing happens , it runs fine just a little lumpy on tick over if anyone can help with this would be great .

[bignev]

Hi there!

 

Is it on petrol and gas it does it, or just gas?

 

At 5 years old, depending on miles too of course, the gas injectors may be wearing out. The installer of our first system said the cheaper ones would quite possibly start to go off after around 25,000 miles. But in fact that one is still fine on ours, yet!

 

I know you had it serviced, but that may not show up just yet.

[thedogss]

hi

it does do the same on both I have found something on a google search that says sometimes the loom wiring plug from the back on the coil pac sometimes gets damaged by the heat/exhaust/ this always make sit misfire so I'm going to check that (soon as it gets light) lol ill let you know how I get on   

[mikebh8]

Hi, please the picture attached.

 

Hope it helps.

[thedogss]

many thanks helps a lot 

[Semmysonic]

You are correct running lpg uses a lot more power so the ignition parts take a beating. I had similar problem a couple of years ago, changed coil, leads and plugs for top quality parts, ( I think there are specialist lpg plugs on the market now) not had a problem since

[crispinchurch]

i have just changed leads on mine a big difference  

spark plugs next on my list

[jimmyybob]

I had this on my 2003 3.3 the problem was the wiring loom for the injectors that had melted on the corner of the rear cylinder head, it was a right mess.

You could simulate the problem by pulling on the loom with the engine running.

I ended up cutting the loom open and recovering each individual wire.

[bignev]

Hey there @@thedogss and @@jimmyybob hope yours stayed sorted!!??

 

Well mine decided it wanted more attention last Monday (Sat today), came up with lumpy running and shaking as the Mrs and kids put it.

 

So here we go again with it, key dance gives P0304 so misfire on cylinder 4.

Turn the gas off to eliminate that.

Swap plugs for cyl 6, same stuff, plugs look ok, apart from no 4 being wet with fuel, so as the ends of the HT leads came off on the plugs thought - try them.

New set of leads - well no of course not was it chuff.

So right then get an old plug and see what's got a good spark - 4 AND 2 don't, bugger.

As they aren't fired from the same part of the 3 section coil (wasted spark type operation) I'm going for dodgy coil.

SO - 3 days later on a next day delivery from fleabay - fitted today and fired up ok.

I will however now also replace the plugs, even though all the ignition parts are just 2 years and around at most 20,000 miles old.

Watch this space hey guys!!!

Edited August 25, 2018 by bignev

[jimmyybob]

Mine has recently started to cut out, but momentarily less than half a second. More like a very brief cough.

I’m wondering if this is also a coil issue.?? @@bignev

[bignev]

Hi pal it could be, but might not of course!

 

If you can get an old plug, try one lead off the engine at a time with the spare plug in the end, I let mine rest on the front metal cross member, and check for any of them not sparking or a poor spark.

 

If only one is down it might be what you've got. With the 2 on ours it was quite a significant stutter / judder, bizarre going on the same day though, very odd.