So my car had been starting to knock up top ~6500-redline, as well as random times when I punch it in 2nd or 3rd gear around ~3k rpm.

My buddy and I got 3 clean logs in and we saw knock in the upper rpm's but about 9 counts.

Here's my latest graph from this weekend at CBRD. It was not a tune session, and this was done during their dyno day/open house. Chad would add more fuel, but was having to target excessively rick target afr's up top to keep it from leaning out. This was with lean spool disabled.

My graph



Works Drop In Filter
Upgraded TB shaft seals
Nisei Short Route UICP
Buschur LICP
Full-Race 1st Gen Turbo Manifold
Works 76mm Downpipe
JUN B.L. 3" catback w/ testpipe
ACT HDSS w/ Streetlite Flywheel
Walbro 255
Stock Turbo
Stock O2 Housing
Stock Intercooler
Forge MBC

This is all chicken scratch to me at the moment. I don't have a laptop to log, so I rely on the help I can get from friends.

Next week I'll be removing my 2+ year old Walbro 255 and replacing it with a new Walbro 255 high pressure unit, as well as installing an AEM UEGO analog wideband.

I'll be logging again after the install to see what I get and adjust fuel accordingly.... hopefully.

-Jalal

 

I notice that I can't post .csv files. What format do these logs need to be converted to in order for me to post them?

Thanks.

ECU noob = me.

-Jalal

 

Let's see if this works!

-Jalal

 

on changing the pump...that's where I would start first.
A friend of mine had the same symptom, lean afr in the upper rpm which caused lean knock...his pump used to humm a lot. Switched to a fresh walbro and all is well.

 

yeah, something was odd, which is why i recommended the pump...

or there is a pickup issue...

The car would start going lean up top even with RICH target AFR's... stock injectors too, so no scaling issues.

cb

 

Yea his car behaved the same way, after adding almost a full point to the target AFR and didn't see much response we chalked it up to the pump.

 

+2 on pump. @ 5000 feet we see the stock pump max at 25 psi when the air temps cool off.

 

Lean spoolup suggests you have a fuel delivery issue, or weird fuel map. What are your fuel trims? AFR should not be in the 14's at 10psi. Also check FPR vac line. An intake leak after the MAF will also do this..

 

nm