Jump to content
LegacyGT.com

Knocking like crazy


black318i

Recommended Posts

OK I don't think this is really a tuning issue, but I figured I'd post here since I'm going to use RR to log. I've been on the same map for weeks with no issues and all of a sudden yesterday I noticed my car was hesitating pretty bad under moderate acceleraton in the 2-3k RPM range. I did a LV when I got home and IAM was .375 IIRC and up to ~8° was being pulled :eek:. What should I log? I was thinking.

 

RPM

load

knock sum

AVCS

WGDC

A/F sensor

throttle open angle

manifold relative pressure corrected

 

Is there anything I should add or remove?

Link to comment
Share on other sites

I think the LV will be the most telling.

 

I would first take a LV of the current condition, reset the ecu and log engine speed, load, knock sum, manifold pressure and throttle opening angle.

 

I suspect bad gas.

Link to comment
Share on other sites

It looks like low level knock..I get it too, it is usually just noise.

 

IAM is dropped due to too much fine learning knock correction..I ended up raising the fine correction listening range to keep my IAM from dropping due to the very low level knock/false knock/noise.

 

Post a LV.

Link to comment
Share on other sites

I'll post some LV's hopefully tonight. I couldn't find any issues and this did start happening the day after I filled up. I added some octane booster and filled up again which was only 6.5 gallons. It took 100 miles but, IAM was back up to 1 yesterday. I will continue to monitor the issue. I was doubtful it was a fuel issue since it only knocked somewhat small area, but things seem to be working out so far. Thanks for the input.
Link to comment
Share on other sites

I watched the roughness monitor continue to increment on cyl 4 then I went away. This seems to come and go, but it went for a long time today. I swapped injectors and there were a few misfires still on 4. Does this monitor any misfire or is it limited to ignition, other? Here is my last then an older typical LV. Only revision between the two is I pulled some timing in two cells where I logged knock then did some smoothing.

1648008323_LearningView_SS_5-2-2010122621PM.jpg.09bde419157c77f519eee90e52484a45.jpg

1621375012_LearningView_SS_4-6-201095656PM.jpg.560b55464a6e6a610245008411d7334b.jpg

Link to comment
Share on other sites

Cyl roughness was at idle and kept cycling from 0-10 for like 20 seconds or so. I shut down and stared again and all was fine I swapped injectors, plugs, and coils and I still see 4 incrementing. not continuously though.
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.



×
×
  • Create New...

Important Information

Terms of Use