ClubCJ - The CJ Lancer Club

Hi can some let me know your thoughts I dont really get into my car very often just like to no the power is there if needed. But today i gave a couple of gutfuls of punch and got 2 big back fires would this be normal or not gave it 2 punches off the start would this be ok i no the evos run rich????? Gary

I have a ralliart and mine backfires every now and again. I just assume its normal? lol mine runs bloody rich

Mine back fires like crazy as well. I heard it's ok as long as it's not backfiring while you are accelerating. It's ok if you are decelerating. Mine back fires when I'm decelerating and I have read that it is due to being too rich and not all the petrol is being ignited and it ignites in the exhaust instead from the heat causing backfire in the exhaust. If it's while you are accelerating then it may be that you are running a bit lean and ignites before it is meant to. Not sure about the detail but if it does better get it checked out before you get an engine fail. Hope someone else can shed more light on this in case I'm wrong.

+1, is it back firing on decel or when you're accelerating?

Not familiar with the TXS stuff but if it's a free flowing 'straight through' exhaust you should expect some back fire and flames

Why did you go EcuTek tune if you don't mind me asking?

my last 2 cars had the ecutek tunes ,and ecutek was on this car when i brought i generally just cruise around and dont give the car a hard time but as i said decide to have a little fun both back fires were off the start dont recall it doing before??/ ?? Gary

Guys,
Sorry but I don't think you should be getting any back firing at all under any circumstances in a modern computer controlled engine.
If it is running way too rich for any given set of engine load and operating parameters then you are just wasting fuel and it should probably be re tuned.
Even the stock factory tunes on a stock engine will be overly conservative and set too rich just so Mitsu can well and truly cover their A** for liability purposes.
Obviously the Mitsu Engineers or the tuner who maps the engine parameters has to maintain adequate margins to prevent pre ignition and detonation etc under any extreme conditions but that programming can be very precisely done and need not be set waaaay too rich.

A call to service dept and a chat with a knowledgeable mechanic or a call to Mitsu customer technical service may be in order.

Just because several people may be having the same symptoms doesn't necessarily make it right or normal!!

I'm quite sure mine is due to having a cat back on stock tune. Runs a tad richer.

That still doesn't sound right Gary.

Guys, A net search " backfiring in turbo cars, yielded this but have a read as there are a number of comments on diff car forums. I would still be talking to a Mitsu Technical people and a very knowledgeable mechanic/ tuner.

I had a stock Mitsu Cordia Turbo in the 80s and a Mitsu Eclipse GST Turbo in US in 90s and 00s and NEVER had any kind of backfire etc -

Turbo charged race cars do it deliberatly. The The burning fuel traveling through the exhaust helps to keep the turbo spinning when off the throttle which of course reduces turbo lag. I think they have moved beyond it now, but for a while most WRC cars actualy had a fuel injected plumbed into the exhaust that was used to create a controlled fire in the exhaust when ever the throttle was closed.
When normal cars decelerate, they let off the throttle which causes the air to be shut off. But while the motor is slowing down, fuel is still being injected into the engine. The unburnt fuel burns in the headers because they're so hot. One of the reasons why newer cars do not backfire, is because most fuel injected cars shut down the fuel injectors after so many seconds of decelerating. This prevents raw fuel from entering the exhaust. Unburnt fuel will destroy a catalytic converter.

Isn't destroying the cat a good thing, you then get a free flow racing cat without having to change it... Lol j/k

LOL ^^

Mine would shoot flames

Mine does it all the time, Every modified 4b11t backfires.