Random KR

[turbotroy]

Hey All! I'm having KR issues and at the most random times. With 110 kr isn't an issue, but with this wonderful 91 octane we have in AZ. Had the car out tonight and just threw in an 02 sensor because of the randomness. Running down the road my knock sensor and scanmaster go nuts if I do anything with the go pedal, but randomly. Sometimes I can ease into it it and it will do knock counts and other times I can nail it and it does what it's supposed to do. I logged with the powerlogger as long as it would run and out of 5000 frames it only recorded actual KR twice. Here's a snapshot and appreciate any thoughts anyone may have. I have an AEM WB 02. Cheers!

 

[Pronto]

Are you saying you're running 110 with alky and get no knock and 91 with alky you do? When you run the 91 what settings do you change on the chip to so you can compansate for the lower octane? Did you replace the wb or stock O2 sensor? I will look at the file later.

 

[SCOOBY DOO]

Appears random. I'd be looking for something hitting...which the knock sensor is picking up.

 

[turbotroy]

Are you saying you're running 110 with alky and get no knock and 91 with alky you do? When you run the 91 what settings do you change on the chip to so you can compansate for the lower octane? Did you replace the wb or stock O2 sensor? I will look at the file later.

I'm running a 91 octane tt chip (non alky) straight out of the box and works well with 110 but not so much with 91. When I get on it my af is at 10.0-10.2 so can't run the alky knob more then about 3, otherwise I drown the engine. I'm trying to follow everything I've read about making the tune correct first before tuning with the alky, but have this random thing going. I found a KR checklist on here and have done 90% of everything on it and will look at whats left. I don't know the build on this engine or which turbo is on it which doesn't help either, but I read about other folks running low 11's/ high 10's with pump gas and alky, so I know these things don't HAVE to have 110 to just drive them. Thanks for the replies and am so glad to be on this forum! I would have probably sold this thing a while back otherwise.

 

[blackgn1]

You are getting high knock with no boost. Sonmething is making the knock sensor go off. My first thought is something hitting. Downpipe on the frame or something. Your boost never got over 11.9 psi. Your are playing it safe. It looks like false knock. Just keep looking. You will find something.

 

[turbojay]

Noisy valve train?