MEGAsquirt A place to collectively sort out this megasquirt gizmo

Car "stumbles" at lower rpms

Thread Tools
 
Search this Thread
 
Old 01-30-2008, 03:18 PM
  #1  
Junior Member
Thread Starter
 
90turboMX5's Avatar
 
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
90turboMX5 is offline  
Old 01-30-2008, 03:35 PM
  #2  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
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 offline  
Old 01-30-2008, 03:47 PM
  #3  
Junior Member
Thread Starter
 
90turboMX5's Avatar
 
Join Date: Dec 2007
Location: Indianapolis
Posts: 167
Total Cats: 0
Default

Originally Posted by Braineack
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, 38 views)
File Type: zip
90turboMX5 is offline  
Old 01-30-2008, 04:23 PM
  #4  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
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 offline  
Old 01-30-2008, 08:37 PM
  #5  
Supporting Vendor
iTrader: (5)
 
FoundSoul's Avatar
 
Join Date: Jun 2006
Location: Duluth, GA 30097
Posts: 803
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 .
__________________
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
FoundSoul is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
stefanst
DIY Turbo Discussion
44
09-28-2015 07:16 PM
TorqueZombie
MEGAsquirt
64
09-18-2015 05:03 PM
Dobzeh
ECUs and Tuning
5
09-17-2015 02:56 PM
Motorsport-Electronics
ECUs and Tuning
0
09-05-2015 08:02 AM



Quick Reply: Car "stumbles" at lower rpms



All times are GMT -4. The time now is 12:09 AM.