MEGAsquirt A place to collectively sort out this megasquirt gizmo
Sponsored by:
Sponsored by:

Needing help with cranking...

 
Old 01-24-2019, 06:52 PM
  #1  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default Needing help with cranking...

Car is starting pseudo reliably. A quick refresher is that this may entirely have to do with my camshafts potentially being out of whack (idlin at 40kPa). If it is that, then I'll stop and walk away (till next week when I'll verify cam/crank timing).

My main questions are in regards to my crank pulsewidths compared to everyone else. I've got 2001+ injectors on my 1999. These were flow tested at 282 @43.5psi - so the REQ calculator is set to 330cc/min injectors = 9.1. Dead time was reduced from 1.3 --> 1.0 (as an attempt to fix the lost sync, it did not - different story). Stock coils, plugs, etc.

A few days ago, I flooded my engine, damn well wouldn't even turn. Came back at lunch time and hooked up my other car to it since I pretty much killed the battery as well. I never really ran into too much of an issue since it never got "that cold" for whatever reason. These past mornings it was 50F, and the last datapoint (at ~35F) was just bad.

Priming pulsewidth is untouched.

Cranking pulsewidth (as seen in MSQ) is...

-12.1 265 (adjusted along time ago - but now untouched - basemap is over 300)
12.3 231 (adjusted along time ago - but now untouched - basemap is close to 300)
34.1 137 (this WAS 177 prior to the change that finally made it start)
63.7 131
84.6 121
107.1 121
128.6 118
148.5 111
170.8 102
201.8 101

Regardless of all this, it still doesn't start how I would like (better than stock). After reading some other threads, it looks like my pulsewidth at cranking...is quite high. So...I don't necessarily know where to go from here. I would imagine that my numbers SHOULD be much higher in practice - but it feels like I still have a ways to go (down) before it feels right. But then all my cranking PW's would be essentially closer to 100 more than anything.

I've attached a few datalogs of various starts at various temperatures. The cold starts are the ones at 48 and 50F. Others are just examples at the higher temperatures. That last attachment is the one where I switched from 500rpm cranking RPM to 400 per some of brain's old posts.

Again...if this is all expected to go away once my potentially* out of sync cams are fixed...then send me on my way.
Attached Files
File Type: msl
2019-01-23_13_177F_crank.msl (137.6 KB, 11 views)
File Type: msl
2019-01-23_12_91F_crank.msl (207.0 KB, 9 views)
File Type: msl
2019-01-24_08_48F_crank.msl (293.6 KB, 6 views)
File Type: msl
2019-01-23_17_91F_crank.msl (323.5 KB, 11 views)
wherestheboost is online now  
Old 01-26-2019, 02:09 AM
  #2  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default

Alright, so I saw some other threads that showed pw's going below 100. Without killing my battery, I went and adjusted pulsewidth's down trying to find a point where the car wouldn't start...and couldn't really find it. Granted I still have the basemap priming pulse - don't know if that's botching me. I've attached the datalog of all my cranks ~15 cranking events.

At cranking PW at 120%, my pulsewidth is 12.9ms (9.1 REQ - cleaned nb2 injectors ~330cc/min @60psi, 1.0 deadtime). at PW = 80%, I'm at 9.2ms pulsewidth. (old reference would be ~14.3ms at 131%PW). Is there an identifier in MLV for cranking pulsewidth? I'll make it a point next time to record the actual PW% to match the datalog crank.

Looking at the datalogs, all of my cranks (defined by me as the time between first drop in voltage --> to the first actual VE table lookup). As I dropped the pulsewidth, I couldn't get cranking any faster than ~1.5 seconds.

Tomorrow morning...would my best bet be to hookup my SUV's battery to my battery, start at something like 60% PW cold (guarantee that it doesn't start), and work my way up - so that I have a consistent starting voltage as well?

The starts still aren't smooth per say. It's definitely a jolt - not a backfire - but I suppose I'm going in the right direction since the crank times aren't changing.
Attached Files
File Type: msl
2019-01-25_17.04.14.msl (1.89 MB, 8 views)
wherestheboost is online now  
Old 01-26-2019, 03:17 PM
  #3  
Senior Member
 
Join Date: Apr 2017
Location: Greeley, CO
Posts: 602
Total Cats: 60
Default

Originally Posted by wherestheboost View Post
Car is starting pseudo reliably. A quick refresher is that this may entirely have to do with my camshafts potentially being out of whack (idlin at 40kPa). If it is that, then I'll stop and walk away (till next week when I'll verify cam/crank timing).
Figure out why you're idling at 40kpa. You're wasting your time. Everything you're changing will have to be revisited once you fix your mechanical problem.
SpartanSV is offline  
Old 01-26-2019, 03:28 PM
  #4  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default

Did more testing this morning. Started at 80% Cranking PW. Took 2 cranks but then started (first crank got to 380 rpm). Second fired right up. Had to move the car...so this wasn't a great day for testing 70F cold start. Next was ~126F and I brought the crank PW down to 60%. Took 2 cranks again. First got to 468 rpm so it triggered the VE table. Guess it wasn't ready yet. Next down to 50% (car's at 140F) now, started right up. Still some oddities. Dropped it down to 40%...still started right up. Altered the VE table in the first column around 100kPa to see if that would do anything...it did not.

Either way, here are the values for Cranking PW% and the resultant PW according to MLV during cranking.


I could see why my engine was essentially flooding way back when - still not sure how it actually started all those times either since the values were anywhere between 120-130% (aka 13-15ms). Looking at a few other threads and cranking pulsewidths (actual milliseconds vs %) datalogs...it seems like this is going in the right direction. I still have yet to hit the "lean" bottom where it won't start.

The main question is...WTF happened such that my resultant ACTUAL cranking PW milliseconds is so high? Since this is independent of my idling at 40kPa. Either way...tomorrow's another day. Hopefully this thread helps anyone else who might be going through the same issue.
wherestheboost is online now  
Old 01-26-2019, 03:31 PM
  #5  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default

Originally Posted by SpartanSV View Post
Figure out why you're idling at 40kpa. You're wasting your time. Everything you're changing will have to be revisited once you fix your mechanical problem.
Will do. That's on the schedule for next week. It's still a great learning experience for me. So I'd only call it ~40% wasting time
wherestheboost is online now  
Old 01-29-2019, 02:42 AM
  #6  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default

Per the other thread, mechanical timing looks good so far. So I went ahead and continued my crank PW tuning. Connected my battery to our SUV's battery so that I don't kill my battery like the last time.

This is the current curve thus far. The PW vs PW% curve still follows the above table, but these are the PW% currently. It's obviously still a work in progress, but it's firing up better than before at least, and I FINALLY found the bottom end (where it actually won't start) - and that's 60%PW at 66F. Still working on ASE and WUE. It seems good once I'm ~140F+, but in the cooler temperatures, it's gotten down to the 11's before it shifts to WUE (then 12s).



It's no wonder my car was flooding itself with the previous previous settings (not even basemap) - since it was clocking in at ~150% at 60F, when clearly...even 75% was enough.
wherestheboost is online now  
Old 02-05-2019, 08:57 PM
  #7  
Junior Member
Thread Starter
iTrader: (-1)
 
Join Date: Apr 2008
Location: Southern California
Posts: 316
Total Cats: -1
Default

Compared the 0105 basemap to my 9900 map. Saw that back then, when my car was having trouble staying on, I fixed it by addressing cranking pulse and ASE. Now that I'm slightly wiser...I went back to the basemap. Saw that 0105 had an REQ of 11.6 (265cc/min injectors - even though they're ~296 at 60psi). Went back to basemap values, and added 6% to compensate the psi differences...seems good.

Turns out I've botched the battery since I've been doing much of this without driving the car. The SUV helped, but right now I think I just need a successful start plus some driving (an hour or two). Had a successful start this morning, but battery volts dropped down to sub 6V.

Since I'm idling at ~13.2AFR to get the lower MAP of ~34kPa, I've kept the basemap ASE, and reduced the WUE dramatically since I don't need much of it. It's doing better...so far.
wherestheboost is online now  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Renhalt
Meet and Greet
3
01-20-2016 02:22 PM
Chased123
Wheels and Tires
25
01-16-2012 02:51 PM
minileprechaun
MEGAsquirt
0
04-26-2011 11:06 AM
aphongt
DIY Turbo Discussion
3
04-02-2009 12:06 AM
arkr9909
General Miata Chat
7
07-20-2008 04:24 PM


Thread Tools
Search this Thread
Quick Reply: Needing help with cranking...


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.