Non-linear injectors. - 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 08-29-2014, 04:43 AM   #1
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default Non-linear injectors.

First off, this is an MS3 built by Reverent, and it worked great with RX8 yellow injectors.

I purchased a set of 1000cc injectors that BEGi is selling, put them in with my turbo system, got everything installed and go to fire it up after changing the injector size in the MS3. Car starts and then goes dead lean and stalls out. Since it was going lean, I start ramping down the injector size and trying to start it. When I hit 450cc/min I was able to get a good idle. Now if I do anything other than idle it goes dead rich, and stumbles and stutters.

Do other 1000cc/min injectors have this problem, and everybody but me knew about it? Or are the injectors from BEGi a huge pain in the *** and big injectors from other places idle like a dream?

I see the "enable non-linear pulsewidths" option in the fuel settings for pulse widths between 0 and 2 milliseconds, but it says you need specific data for your injector characteristics in that range if they are horribly non-linear like mine... and I don't have that data.

Thanks for listening to me bitch.

Oh, and any suggestions would be great!

Keith
Twodoor is offline   Reply With Quote
Old 08-29-2014, 05:14 AM   #2
Elite Member
iTrader: (1)
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,658
Total Cats: 39
Default

Set req_fuel at the correct amount. With the EV-14 injectors you'll find you have to ramp up the numbers in the VE table considerably around idle, everywhere else will be more 'normal'

No need to mess with non-linear PW settings.
richyvrlimited is offline   Reply With Quote
Old 08-29-2014, 08:53 AM   #3
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,440
Total Cats: 198
Default

EV14 injectors generally require a very high number around idle, and only slightly more fuel in the rest areas compared to idle.
Reverant is offline   Reply With Quote
Old 08-29-2014, 08:56 AM   #4
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default

So, just set the injector number to 1000 and then richen the idle area of the man manually.

Got it!

Keith
Twodoor is offline   Reply With Quote
Old 08-29-2014, 09:29 AM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,833
Total Cats: 1,786
Default

yes, and correctly set your deadtimes. you'll end up with VE% values around 60% or so in idle cells.
Braineack is offline   Reply With Quote
Old 08-29-2014, 08:38 PM   #6
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default

First thing I did was adjust deadtimes.

I am starting to wonder if I have a gross conceptual error in how I think this works.

I was under the impression that I just had to put in the new injector numbers, and then it would require just minor tweaking of the map to even everything out. Isn't that how it should work?

I ended up having to take my VE table and add +60 across the board. Now it idles OK and runs well enough for me to use VE Analyzer Live to dial it in the rest of the way.

I have been running E85 the whole time on the old injectors, and now on the new ones, so that should not make a difference should it?

Any help appreciated,

Keith
Twodoor is offline   Reply With Quote
Old 08-30-2014, 06:11 AM   #7
Senior Member
Thread Starter
iTrader: (2)
 
Join Date: Mar 2014
Location: Meridian, Mississippi
Posts: 637
Total Cats: 42
Default

I may have no real idea why, but everything is working great! Car is running like a dream rather than a nightmare like when I first started it with the new injectors.

Keith
Twodoor is offline   Reply With Quote
Old 09-01-2014, 08:36 PM   #8
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,174
Total Cats: 2,575
Default

To answer your question about req fuel from the other thread:
I think the huge difference for you lies in the fact that you switched from completely different styles of injector. You went from a ev6 to ev14 and tripled in size. rx8 ev6's are also known to have the funky deadtime issues going from cold to hot.

When I had my car on pump gas on ID1000's, and then e85 on ID1000's, it was as simple as switching req fuel by 30%, and anything else I touched was just really really minor stuff.
18psi is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
WTS: 460cc RX-7 Red Top Injectors albertogti117 Miata parts for sale/trade 6 10-08-2015 10:09 AM
Red NB Injectors 260cc $60 ericwh Miata parts for sale/trade 3 09-24-2015 08:47 AM
DIYPNP Won't Stay Running huesmann MEGAsquirt 19 09-16-2015 08:11 PM
1991 Turbo Miata partout tottestad Miata parts for sale/trade 18 09-14-2015 08:52 PM
FM 1.8 Mani, Test Pipe, HP+, Injectors Chooofoojoo Miata parts for sale/trade 6 09-13-2015 11:01 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 01:02 AM.