hot lean restarts - 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 03-01-2012, 10:17 AM   #1
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default hot lean restarts

How many others still have this issue even with altered MAT corrections?
restart couple minutes later and see AFR lean out till you start get going enough.
Techsalvager is offline   Reply With Quote
Old 03-01-2012, 10:22 AM   #2
Senior Member
iTrader: (8)
 
Join Date: Jun 2010
Location: Navarre, FL
Posts: 1,127
Total Cats: 39
Default

yep. would be really nice to have an idle specific MAT correction table that would taper off with rpm... my understanding is MS1 has this, but not anything since then.
aaronc7 is offline   Reply With Quote
Old 03-01-2012, 10:27 AM   #3
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

Quote:
Originally Posted by aaronc7 View Post
yep. would be really nice to have an idle specific MAT correction table that would taper off with rpm... my understanding is MS1 has this, but not anything since then.
The question is not about the MAT correction, its about the hot restarts.
I would say though phase in MAT correction over a certain time from restart.
Techsalvager is offline   Reply With Quote
Old 03-01-2012, 10:40 AM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,838
Total Cats: 1,787
Default

Not enough to care about. I can run the car pretty damn lean on seq. fuel.
Braineack is offline   Reply With Quote
Old 03-03-2012, 11:25 PM   #5
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

not a question of caring its a question does it still happen to whoever.
Techsalvager is offline   Reply With Quote
Old 03-04-2012, 03:31 PM   #6
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 408
Total Cats: 19
Default

Restarting my car is a train wreck after I get off track.
FatKao is offline   Reply With Quote
Old 03-09-2012, 02:07 PM   #7
Newb
 
Join Date: Sep 2006
Posts: 20
Total Cats: 0
Default

Hot starts are the bane of my life. I find the only way to get going is to crank for several seconds then blip the throttle as I release the key. If I don't do that then it might sometimes fire up but will then stumble along at 400-500 rpm until I blip the throttle. I've tried alternately increasing and decreasing the cranking pulsewidth by 10% or even 20% but neither seemed to improve.

I stopped to fill up today and it took me three tries to get started. Embarrassing with a queue at the pump.
Martin Y is offline   Reply With Quote
Old 03-09-2012, 06:02 PM   #8
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

fatkao can you expand on that.

MartinY thow your tune up and a datalog if you have one at the time it happens
Techsalvager is offline   Reply With Quote
Old 03-09-2012, 11:39 PM   #9
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 408
Total Cats: 19
Default

I see intake temps around 140F from heat soaked everything after the car sits for 30m-1hr after a session. The last event I did the ran 2 out of 3 run groups and the restart after the 30 minute pause was never pretty. Usually have to keep the throttle open a bit and the RPMs at 2-3k for 30s-45s to give the intake tract a chance to cool down a bit before the idle is stable.

One thing I need to do is move the sensor so it's not on the same side of the intake tubing as the radiator, currently it's about 4" off the throttle body coming out the drivers side. Another thing I need to do is switch to a metal intake pipe vs the plastic I have now.
FatKao is offline   Reply With Quote
Old 03-10-2012, 03:12 PM   #10
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

what EMS fatkao if its MS can you upload a tune and datalog?
Techsalvager is offline   Reply With Quote
Old 03-10-2012, 11:09 PM   #11
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 408
Total Cats: 19
Default

MS3, I'll see if I can find a datalog of it happening. Not sure if I logged it. Today I had the car dyno'd and my MAT was 120F after sitting ~20 minutes after 2 pulls. It wasn't very happy restarting but with some throttle it deals.
FatKao is offline   Reply With Quote
Old 03-12-2012, 07:07 AM   #12
Newb
 
Join Date: Sep 2006
Posts: 20
Total Cats: 0
Default

Quote:
Originally Posted by Techsalvager View Post
MartinY thow your tune up and a datalog if you have one at the time it happens
Fixed. When I spent some time on the datalogs instead of just whining about it, it was obvious that -----footing around with 10% changes was a waste of time. I needed to halve the cranking pulsewidth and work from there. Starts right up now.

We now return you to your regular thread:
Martin Y is offline   Reply With Quote
Old 03-12-2012, 08:38 AM   #13
Senior Member
 
Join Date: Mar 2006
Location: Schwarzenberg, Germany
Posts: 1,497
Total Cats: 81
Default

ould you please tell us, what your reqfuel is and what the cranking PWs were before and after?
Zaphod is offline   Reply With Quote
Old 03-12-2012, 10:00 AM   #14
Newb
 
Join Date: Sep 2006
Posts: 20
Total Cats: 0
Default

Req. fuel 12.5ms

Before: PW 15.5 @ 85C wouldn't fire without blipping the throttle.

After: PW 7.95 @ 94C started easily.
Martin Y is offline   Reply With Quote
Old 03-12-2012, 08:31 PM   #15
I'm Miserable!
Thread Starter
 
Join Date: Jun 2009
Location: albany, ga
Posts: 1,869
Total Cats: 3
Default

Quote:
Originally Posted by FatKao View Post
MS3, I'll see if I can find a datalog of it happening. Not sure if I logged it. Today I had the car dyno'd and my MAT was 120F after sitting ~20 minutes after 2 pulls. It wasn't very happy restarting but with some throttle it deals.
check datalogs, is gair moving around from 100?
If so thats probably your hard to restart issue mostly.
if your MAT correction table is 0 across the board then your MS is causing a lean condition whenever it reads a higher air temp.
Techsalvager is offline   Reply With Quote
Old 03-12-2012, 11:29 PM   #16
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 408
Total Cats: 19
Default

Meant to get a MSQ posted today, hopefully I'll remember tomorrow. All my recent MSQs are on my work laptop and digging that out of the car at home is far too much effort.

I have some adjustments to my MAT correction table but I'm not sure if it is enough to keep everything 0.
FatKao is offline   Reply With Quote
Old 03-14-2012, 01:46 PM   #17
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 408
Total Cats: 19
Default

Have a MSQ.

Just looked at a log, my Gair is completely fucked, sits around 93. If I adjust it to stay around 100% should I drop 7% fuel across the board to keep AFRs about even?
Attached Files
File Type: msq CurrentTune.msq (158.0 KB, 66 views)
FatKao is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Back to Stock Part Out!! Turbo Parts, MS2 Enhanced 01-05, Suspension, and MOAR! StratoBlue1109 Miata parts for sale/trade 16 10-02-2015 10:39 AM
why is my car running like pewp? (tune/datalog) itsMikey MSPNP 3 09-28-2015 07:40 AM
DIYPNP problem PA0 VICS output spidy MEGAsquirt 7 09-24-2015 04:14 PM
VE values too low? compuw22c MEGAsquirt 4 09-12-2015 08:42 PM


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 12:20 PM.