04 MSM, MS3 PNP Pro 3. Idle and Pulsewith Issues - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members

MEGAsquirt A place to collectively sort out this megasquirt gizmo

LinkBack Thread Tools
Old 04-29-2016, 07:40 PM   #1
Thread Starter
Join Date: Apr 2016
Posts: 1
Total Cats: 0
Unhappy 04 MSM, MS3 PNP Pro 3. Idle and Pulsewith Issues

Hi All,

My name's David Adams, I don't post much (if at all) but I do a lot of reading and searching. This issue, however, has my tuner and I perplexed. He says this is something he's only seen with Mazdas so I'm posting here in an effort to help get to a fix and I'll try to be as consise as possible.

My car is an 04 Mazdaspeed Miata, mods currently are wideband, 10.6 pound flywheel, clutch, intercooler, intake, exhaust, boost at 12 pounds and megasquirt MS3 PNP Pro. What my car is doing is very strange so I'll try to be accurate. It has the (seemingly typical) warm/hot restart issues whereas it doesn't want to. It also, even when cold, will sputter and sometimes die if you hold the clutch in after starting. The only way it'll "catch" idle is if you let the clutch out immediately after starting.

The car also hesitates when getting on the throttle from idle. Of course, the harder and quicker you push the throttle from idle, the more likely it is to konk out and die. Very strange.

It also, and I think this is related, won't enter launch control. Come to a stop, clutch in, 1st gear, hard down on the the throttle, it'll just sputter and it won't go above 500RPM. At all. Even if you slowly rev up to 4k then put your foot down, it'll just sputter itself almost to death.

Lastly, when "revving down" from any engine speed (for example when coming to a stop at a redlight), if you leave the clutch depressed, the engine will cut out.

My tuner, wanted me to mention that the pulsewiths with the clutch OUT are "normal" at around 2.5ms. However, with the clutch DEPRESSED, they jump to 8ms. I have no idea what that means (maybe someone can explain that to me).

I hope I didn't ramble on too much while still giving all information needed.

I've posted the MSQ tune and a quick datalog of me going clutch in, clutch out, trying to start with the clutch held in and starting with the clutch out. Let me know if I need to post a driving datalog as well

Thank you all so very much and please pardon my ignorance. Though I am a SysAdmin, this vehicle stuff perplexes me to no end.

Thank you all again!

David Adams
Attached Files
File Type: msl startup and idle issues.msl (2.66 MB, 49 views)
File Type: msq WideBand MSM.msq (251.8 KB, 33 views)
David_Adams is offline   Reply With Quote
Old 04-30-2016, 05:44 PM   #2
Cpt. Slow
iTrader: (25)
curly's Avatar
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,109
Total Cats: 518

Pulsewidth is how long the injector fires. It's the final voltage the MS gives out after it uses your tune, including fuel table, WUE, AE, etc. 2.5 is pretty normal, 8 would be pig rich. Your "tuner" most likely just needs to "tune".
curly is offline   Reply With Quote
Old 04-30-2016, 06:34 PM   #3
Supporting Vendor
iTrader: (33)
Ben's Avatar
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99

I noticed your MAP signal was very poor and initially assumed your MAP line was pinched. However then I noticed that the lags are turned way down. This motor would respond like poop. Start with the lags at 90. (higher numbers = better response)

Launch control is turned off in the tune... Either way, you shouldn't be leaning on a 2-step if the car runs badly.
Attached Thumbnails
04 MSM, MS3 PNP Pro 3. Idle and Pulsewith Issues-80-1_5038931f2258ab93eba396da3b89d45bdd9cc1de.png  
Ben is offline   Reply With Quote
Old 04-30-2016, 10:41 PM   #4
Boosting since 1984
iTrader: (1)
stefanst's Avatar
Join Date: Sep 2011
Location: Levittown
Posts: 1,198
Total Cats: 68


Last edited by stefanst; 05-01-2016 at 12:22 AM. Reason: Lack of comprehension.
stefanst is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
1992 Turbo 1.6 won't start after upgrading from MSPNP to MSPNP2 Buckles MSPNP 25 05-25-2016 10:58 AM
MS3 Basic 6000 rpm backfire and check engine light poormxdad MEGAsquirt 67 04-24-2016 04:50 PM
Cut the bump stop or not Dietcoke Suspension, Brakes, Drivetrain 22 04-19-2016 10:23 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 12:14 PM.