got stumbles narrowed down

Now that the weather has gotten nicer, and ive chased all the bugs out, I have a stumble issue in all gears. It is less and less as the gears increase. It only happens at light throttle in the 2000-4000rpm range under vaccume to slightly above.

LTFC was all over the place. and i think i found out why.

I set the car to run in open loop all the time. and the bog/stumbl got massivly worse.

Doing tons of logging, and the AFR mill max out at times to 20:1.(cause of the stumble.) This seems to happen in the 20-100g/s range. when slowly running through the gears in town.

(cause of the stumble.)

 

My plan is to set the load comp table to 0, Scale the Maf Then use the mrp load comp table to get those spots back to my primary target afr...

 

sound like a plan?

 

here is a couple of logs on what im talking about.

romraiderlog_20120127_lean spot.csv

romraiderlog_20120128_153856 lean area.csv

romraiderlog_20120128_153917 light throttle lean.csv

 

Mods to my car.

 

crower 264 cams (not BC)

Custom 8.75:1 pistons

el header downpipe, no kitties

bnr ht68

avo inlet

id1000's

IPR TMIC

 

PS I'm eyeballing the SD on 32b ecu on RR as i'm pegging the maf @ 4.95v in 3rd@6300..and it seems like the easiest fix.

 

mike

Have you gotten this sorted out yet? im having the same issues and my afr maxes out the same way like that but only in vacuum, for example off the throttle in gear or in between shifts.

It's hard to tell from just eyeballing those logs but I think you have a MAF scaling problem.

 

Also, since IAM is 0.625, stay out of boost until you get your MAF scaling good for 0-60 g/s or so, and then slowly turn up the boost (bit by bit) and work on MAF scaling after every pull or two.

 

SD for the 2005 MT OBXT might be released within weeks. But keep in mind that SD is still quite new, so there may be a few revisions to the code before it's really really 'done.' And you'll have an easier timing tuning it if you get your MAF scaling dialed in first. Plus it's good practice.