Mazda3 Forums banner
1 - 1 of 1 Posts

1 Posts
Discussion Starter · #1 · (Edited)
I have a cold air intake, blow off valve, and basic Cobb Partial Stage 1-af tune.

Screwed my first engine and had it replaced with a DISI from a CX7 with 40k miles on it.

I had all my original parts moved to it, including my bigger turbo.

Replaced the spark plugs. Cleaned the EGR valve. Replace both O2 sensors.

Upon completely cooled off start up while in open loop fuel state, runs completely fine. The moment it goes into close loop the turbo spools and engine miss fires. RPM become mildly erratic around 2k. Within 20 second the problem stops, and the engine runs fine the rest of the day.

If I interrupt the startup process by increasing rpms to 2.5k with the peddle, the turbo stops spooling. I can even get the p0300 code to clear by simply interrupting the morning idle relearn process (warm up) every morning for a few days. Zero specific cylinder code. Only p0300.

I have also had the throttle body through a code due to throttle alignment with the peddle.
(Forget the code). I have a new throttle body in the mail, but I don't see that causing a p0300.

Upon cleaning the EGR valve I notice my EGR pipe was missing its gasket. Like forgotten by the last mechanic. I made sure it is tighten down without it. Problem still exists.

Edit: during the problem my turbo pressure jumps up and down between 0 and -6.

Any ideas would be greatly appreciated!
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.