Motor misfires

 

Ok but ... some of us need a little more information ....



And maybe you should have your OBDII Diagnostic port checked with a professional scanning tool for any and all DTC (Diagnostic Trouble Codes) and what the monitor status is?

 

I have a '07 CX-7 Touring which is starting to misfire a lot, only when the engine is cold. I am getting P0301 codes. I cleaned and swapped the plugs and I swapped the coils. Nothing changed. Seems like the engine may think it is warm, when it's actually cold. Is there a sensor for that?
Thanks
Mike

 

If you used a Diagnostic tool as I suggested ...did you clear the DTC and then re-check after you cycled the engine?
Please STOP swapping parts unless you put them back where they originally came from.

 

Hi Callisto, Thanks for your response. I did Erase codes, but the P0301 comes right back. Once the engine is warmed up, it runs smooth again.

 

Most likely your injector is plugged. This is a very common issue as those injectors have paper filters. Use a fuel injector cleaner to see if this will solve your problem. if you are successful remove the rail and replace all injectors seals and replace all paper filters with stainless steel.

If you are not you will need to replace that injector. Either way, you need to remove the rail and change all seals.

When the engine is cold the need for fuel is higher than when the engine is warm.

 

Like the other member says it might be dirty injectors. If thre is even a small varnish build up around the needle valve and body it could reduce the proper amount of fuel needed for a particular fueling cycle controlled by the ECU.

Most fuel injection cleaners in the USA are heavily regulated and are not as concentrated as they use to be. I have PM'd you with some information that will speed the cleaning process and not need to remove or replace any fuel system parts.

Cheerio.....

 

Thanks, again, for speedy reply. However, I did not see your PM to me.

 

Ya sorry I sent it to short-stack by mistake. Re-check your PM?