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Mtnbker3531

Mtnbker3531

Greenie N00B Member
Greenie Member
2013 Mazdaspeed 3
158000
Chicago IL
Occasional stumble/breakup at WOT
Built motor. BNR S3. PD tuned and all supporting mods
New OEM coil packs within the past 1000 miles.


So I have had a cylinder 1 misfire code twice now, plugs only have about 2500 miles on them so I decided lets just replace all my coil packs since they were original and if one is going they probably all will sooner than later. Same code returned a couple hundred miles later. Car pulled hard and I couldn't feel anything out of the ordinary when the CEL triggered.

At this point I decided to put a brand new spark plug gapped to .026 in cylinder 1 as well as swap #1 and #4 coil packs even though they are brand new. I also did a compression test to see if anything was abnormal with cylinder one. Compression shows 175psi on that cylinder. I did recently put a different wiring harness on the car over the winter that I stripped down and rewrapped to make it look nicer. I didn't see anything abnormal about any of the wiring but it is worth noting I didn't have any of these issues on the original harness but that may just be coincidence.

I was able to capture a data log of this behavior and its attached. I'm far from an expert at reading data logs and using the info to troubleshoot but what did stand out to me is the fact my IDC is showing well over 100 percent, maxing out at 120. I could feel a misfire/stumble on this log but it did not feel like the abrupt fuel cut that I've experienced with a boost leak. What is that IDC indicative of?

I have 4 brand new OEM injectors and was planning to get some new Overspeed or CS seals.

HPFP is a new Hitachi unit also new CS internals under warranty and the PRV was replaced with an OEM all with in the past 1500 miles.

@Enki and anyone else that can help!
 

Attachments

Probably needs a tune touch up or something hardware wise changed and is causing you to run rich. Maybe rotate your air filter 90 degrees? Wiggle the MAF wires while idling to see if you need to replace the connector?
 
Awa I did have a boost leak and it was recently fixed, It was pretty obvious from fuel cut, if there is a smaller one causing this Id have to check other couplers.

Enki the HPFP as well as the internals and PRV have been replaced since my tune was finalized.
 
If afr is in the 9s sort that first to see if it cleans up the misfire
 
Well my MAF is nice and oily.

I noticed I was getting some blow by coming from the valve cover breather into the intake a couple months ago. I cleaned the MAF and the intake at that point and haven't had any issues.

Well the MAF and intake have oil contamination again. I guess I'll re route one of my catch cans to alleviate this.

I'd imagine a dirty MAF could cause some issues.
 
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