Knock Retard at WOT..

J

jonapod

Member
:
MS3 Black Mica
OK folks - I have an 08.5 MS3, MS CAI, AP running v1.05 MSCAI 93. Running 93 octane.

After a reflash i consistently get 1-4 KR on WOT, and several times I have had audible knock (nailbyt) ..
AFR's are in the high 12's, LTFT is 10-15.

After a learning period, it settles down with occasional KR but still with AFR in the 12's..

I need to check I don't have a leak on the intake side - any other suggestions please..?

I have a similar but lesser experience even with the stock tune, so I don't think it's the accessport.

-jc
 
Those LTFT's are way too high. 1 - 8 is considered "safe". What intake is it exactly? and does it have an air straightener? I'm not an expert by any means but something needs to be done. Hoping people with more experience will speak up. I would definitely suggest calibrating your MAF using the ATR instructions. In the meantime you could try running the 91 map and see if that helps at all.
 
I agree the LTFT are too high - it's Mazda CAI w/ straighter - installed when i bought it new.
I tried the 91 map without any real difference which makes me think it might be intake related. oh, and i installed DENSO ITV22 Iridium plugs today, which don't seem to have helped!
 
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MS3 GT said:
just curious....... whats knock retard?
Click to expand...

Knock Retard is when the ECU detects knock or pre-knock conditions(detonation) in a cylinder, retards the timing and adds fuel to protect the engine.

Knock can be caused by a number of things - lean fuel ratio, bad plugs, oil/gunk in the intake.

Look up 'engine knock' on wikipedia for more information.
 
Was it knocking before you got your AP ??? Many people claim the "stock" AP map isn't quite the same as the map you had before the ap.

Those ltft's are high and your A/F is way lean.

Try some different maps. check mzdspd.com
 
Problem solved!

I have no air straightener!!

I pulled the CAI apart and presto - no straightener..

This was Mazdaspeed dealer installed before I even picked up the car brand new. I had to wait on it for several weeks as they were waiting on a shipment as the original CAIs were pulled because they didn't have them..

So i've been driving around lean for 10K miles wondering why the car seemed to be pulling timing.

THANKS to my Cobb Accessport - until I monitored the AFR's and LTFT's I didn't know what the problem was.

Off to buy a $10 straightener right now..

Yeah!
(dance)
 
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Wow, good thing you checked. I would definitely make your mazda dealer aware of this. Even though you're correcting it now, things could happen down the road due to driving for 10K miles with improper ratios/knock/etc and it would be THEIR fault. Kind of funny that an aftermarket product that will void any warranties on the car was the thing that detected a mistake made on Mazdas part. Irony at its' best.
 
MS CAI dealer installed? Please check for your air straightener!!

New AEM air straightener installed. 6 bucks from JCSpeed.

LTFT's went from 8-15 to 0-6. Car still needs to learn.
AFR at WOT is in the 11's. yeah.

Told dealership they didn't install the air straightener. Didn't have a CLUE what I was talking about. Good job I didn't blow the engine on a green warranty, dealership installed part. doh.

SO - if you have a MAZDASPEED COLD AIR INTAKE and you didn't install it yourself - check - it takes 10 minutes and might save you car..
 
wait so your saying that an air straightener made your afr's go from high 12's to 11's? Sorry dude but that doesnt happen. Fuel trims will settle yes and maf reading will stabilize, but there's gotta be more to the story for a point drop in the afr's. I drove my car with and without and that was not the case.
 
OP does not have much in the way of power mods. Unless or until OP has a catless dp/rp or a tune or other mods that raise boost, the colder plugs are not going to help and are candidates for fouling. But for some posters on this thread with raised boost, tunes and catless bell mouth dp/rp's, one step colder is very appropriate, IMHO.
 
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