Rough idle or rough acceleration could be explained by it since it tells the computer the air temperature is higher/lower than what it actually is and therefore adjust the fuel incorrectly to cause it to run rich/lean. That in return gives you a not so optimal combustion and causes the engine to run inefficient.

I'm glad you appreciate the help - I just hope it turns out to be good advice

 

Hi just got some info yesterday on how to work with the ross-tech software. so here is what I found out the misfire is happen on 1,2 and 3 it just not enough to trigger code like cyl number 1. Yesterday I got cyl number 2 fault. check engine light is still on and off and when off the EPC light stay up but give me no code at all that I can use I will check this and see if I can get it to give me a fault code on the EPC, on a short run of less then a minute I had 27 misfires from all 3 cyl most of 1 and 3 some on 2.


im still planning to take the intake, do you think maybe I should conceder new ignition coils how often you suppose to change them ?

 

That changes the troubleshooting steps for sure. You are now looking indeed at something that causes global misfires on all cylinders not just a single one. There is certainly a chance that the TB or the MAF could be at fault.

You can replace all the ignition coils and spark plugs for starters (with the intake temp sensor) and see if that helps but there is no guarantee it will work. At the very least you will however provided your car with a nice tune-up. I replaced those around 60k since VW/Audi had some serious issues with failing coilpacks until 2010 I think so your car should still be within that range of bad coil packs or prematurely failing ones. As mentioned I would replace them anyways during regular maintenance of the car's life simply because they go slowly bad and they are known to be weak. Misfires can certainly be caused by bad coilpacks and therefore a good place to start.

As a general rule I would replace the coilpacks and spark plugs every 80k. I'm sure that's overkill but since both work hand in hand but it provides a nice "cheap" tune-up (better performance and gas mileage is usually the result).

 

Ok here is a little update....


So I went and bought new coils put them in and Great car is running again check engine light is not on anymore and the car run fine on the highway BUT something still feel not right when im in low RPM it feel like the car dose not have power like it low on fuel or something but when I give it some gas everything is going good and the car speed up quick. the feeling the I describe happen around 1k-2k RPM from 2.5 and above everything seems to be ok. I did a quick low speed loop around and it still show misfire on cyl 1 and cyl 3 but when im accelerating it 0 all the misfire count and when im idle around it start count again.


Any thoughts on what else ? maybe the injectors but why only 1 and 3?


im thinking to pour a bottle of injectors cleaner to check if it will help.


Thanks

 

Did you do the valve cleaning yet? That is a known issue to cause misfires. Another known issue:bad catalytic converters - let's hope it's not that because they are expensive.

 

No did not clean the valve yet. I will take everything apart hopefully this weekend and give it a good clean. will let you know the result

 

Any luck?

 

Hope you can share some insights if you ever had this issue fixed. Thanks!