Car "stumbles" at lower rpms - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 01-30-2008, 04:18 PM   #1
Junior Member
Thread Starter
 
Join Date: Dec 2007
Location: Indianapolis
Posts: 167
Total Cats: 0
Default Car "stumbles" at lower rpms

Ok, I finally got my car running decent. LC1 reads fine, yeaa!!!. I do have a problem and it is that at lower rpms (1000-3000rpms) when I'm cruising and apply throttle the car stumbles, its not smooth at all. I did many logs and used the analizer but I cant get rid of it. Could it be a timing issue or VE table is not adjusted right??
Any ideas?
BTW the car does have a 7lbs flywheel but I dont belive it makes such drastic driveability issues. Im sure its the tune, but I dont know where to look.
here is my (well, brainecks tune modified to suit my car) tune
Attached Files
File Type: zip From braineck, ready to go.zip (5.5 KB, 42 views)
90turboMX5 is offline   Reply With Quote
Old 01-30-2008, 04:35 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,868
Total Cats: 1,790
Default

did i give you that fuel table?

how rich are you? from glancing at the msq it looks like too much fuel.

post a log as well, that would be more helpful. Try turning off the CLT-related air density correction....go to advanced and turn it to normal....
Braineack is online now   Reply With Quote
Old 01-30-2008, 04:47 PM   #3
Junior Member
Thread Starter
 
Join Date: Dec 2007
Location: Indianapolis
Posts: 167
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
did i give you that fuel table?

how rich are you? from glancing at the msq it looks like too much fuel.

post a log as well, that would be more helpful. Try turning off the CLT-related air density correction....go to advanced and turn it to normal....
Yea, you posted that fuel table but I modified quite a bit.
Here is a log and here is my other map that I smoothed out by hand after analizing the 1st map (the one I posted) through the log.
I didnt have time to try it yet but it should make it better.
Cruising AFR is 14-16 it jumps all over.
Attached Files
File Type: zip 2nd test.zip (286.1 KB, 36 views)
File Type: zip Analizis by hand plus MVL.zip (5.5 KB, 32 views)
90turboMX5 is offline   Reply With Quote
Old 01-30-2008, 05:23 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,868
Total Cats: 1,790
Default

everything looks fine, to me it looks rich in cruise. 11.5-12:1.

I see a few times on the log where it freaks out. like you blipped the throttle over and over.

I see the MAP go to 80 and then to 12 and back up and down....is this when you are having the issue? 5343sec on the log. 2nd test.
Braineack is online now   Reply With Quote
Old 01-30-2008, 09:37 PM   #5
Supporting Vendor
iTrader: (5)
 
Join Date: Jun 2006
Location: Duluth, GA 30097
Posts: 798
Total Cats: 0
Default

Is AE kicking in during cruise? If the MapDot/TpsDot threshold is too low, or if there is noise in the signal, you can have AE kick in when you don't want it and make AFR wildly jump around...

If it's just happening at tip-in it could be AE just needs to be dialed in.

Otherwise it may just need a good steady state tune... I've felt cars run like CRAP that just needed a good tune, and people had been driving them that way for a while and dealing with it. Tune it and a beautiful thing happens .
FoundSoul is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
The "other" spool question stefanst DIY Turbo Discussion 44 09-28-2015 08:16 PM
VE analyze and Autotune seems funny (noob) TorqueZombie MEGAsquirt 64 09-18-2015 06:03 PM
ms2e No Rpm Signal Dobzeh ECUs and Tuning 5 09-17-2015 03:56 PM
ME221 Now has Autotune and Long Term Fuel Trim Tables Motorsport-Electronics ECUs and Tuning 0 09-05-2015 09:02 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:22 PM.