All of the sudden leaning out everywhere - 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 04-06-2016, 12:40 PM   #1
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default All of the sudden leaning out everywhere

Hey all, finally got the car running and it's been great over the past week, yay!

Today, something new. I drive to work, and I as soon as I get off the highway, the car is running a bit leaner than usual. As in, at idle it will be about 18AFR

Also just low speed cruising around the base, I get inconsistent drivability and jerking, all the while the AFR is hovering (as though offset) by 3-4 points higher than normal.

Since I haven't touched the tune in months and months and it was driving perfectly fine over the past week, is there anything I should be on the lookout for? I haven't noticed any cracked hoses or leaks, but I literally just observed this this morning. I don't know if I should just baby the **** out of it on the commute home or just tow it. I don't have my laptop so sorry I cannot be much help.

Just probing your collective minds for troubleshooting this evening.

Things I know I need to do:
Tighten up the alternator belt, it squeals on startup
Replace Idle Control Valve (could this be the culprit?)


Maybe bad fuel pump?

Last edited by psyber_0ptix; 04-06-2016 at 02:01 PM.
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 12:41 PM   #2
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,199
Total Cats: 2,584
Default

do you have baro correction working right? is ts afr lining up with gauge?
18psi is offline   Reply With Quote
Old 04-06-2016, 12:51 PM   #3
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Unfortunately laptop is at home. I'll check this for sure when I get home.
This is on the MTX-L

Barometric pressure history shows fluctuations of less than an inch over the past 3 days. But no change from yesterday when the car was working fine.
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 12:58 PM   #4
Elite Member
iTrader: (17)
 
Join Date: Aug 2007
Location: Fort Myers, FL
Posts: 2,791
Total Cats: 130
Default

Do you have a fuel pressure gauge on the car? Not Miata or megasquirt specific but I've had fuel delivery issues before. I've had an in-tank filter sock pick up rust/junk and clog. It would be fine for 15 minutes or so, then start leaning out after driving a while. I've also blown a o-ring on the fpr on a returnless fuel system that did the same thing you describe. Fuel pressure would show if something like that could be the issue.

The only other thing I've seen randomly affect afr like that is a cracked/pinched/disconnected MAP sensor, but that will typically make you rich at cruise not lean.
pdexta is offline   Reply With Quote
Old 04-06-2016, 01:01 PM   #5
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Thanks for the insight. I don't have a fuel pressure gauge until I swap in my fuel bits. I did note that a couple days ago the fuel pump (which is usually loud on startup, kept wining even after warming up). But I didn't want to jump to conclusions and it hadn't happened since. I'll check around but aside from starting my fuel system project sooner than desired, I don't know what else to do if in case this thing is clogged.

There's also plenty of gas in the tank.

I hope to god it's not the injector(s).
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 01:08 PM   #6
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

Is it only lean after getting off the highway and immediately after?

I'll idle lean at highway off ramps, haven't been able to figure out why. After idling for a while it will fix itself.

It almost acts like a lean hot restart, I notice it more lately since I've switched back to 91 from e85. I'm wondering if it's not because my cruse PW is so low, maybe the injectors cook a bit while rolling down the highway for 30 miles?

I'd try and limp it home, if it were me. You'll have warmup fueling helping for a while, and hopefully ego to pull back some. Stay under 75 kpa or so and you can get away with a lot on the fueling, just doesn't always drive so smooth, melts sparkplugs...
deezums is offline   Reply With Quote
Old 04-06-2016, 01:21 PM   #7
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

It's actually everywhere now. Idle, cruise, slow, Swift but not loaded. Egt's are higher than normal
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 01:40 PM   #8
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Might try replacing fuel filter just for ***** and giggles
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 01:41 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

log first.
Braineack is offline   Reply With Quote
Old 04-06-2016, 03:33 PM   #10
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Quote:
Originally Posted by Braineack View Post
log first.




I hope I can make it back, it doesn't want to stay running at idle.
Attached Thumbnails
All of the sudden leaning out everywhere-untitled-1.png  
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 07:12 PM   #11
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

So i dropped into Rosenthal and bought a fuel filter anyway and changed it out. Topped off the tank too.

This log is after the 6th attempt to get it to start without stalling out. The log starts of just idling in the driveway then took it out around the block. I didn't want to drive too much on it.

I haven't plugged my computer up to the car for a long time so I don't know what would change between yesterday and today.
Attached Files
File Type: msl 2016-04-06_17.56.20.msl (770.2 KB, 52 views)
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 07:32 PM   #12
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

Quote:
Originally Posted by psyber_0ptix View Post
..I did note that a couple days ago the fuel pump (which is usually loud on startup, kept wining even after warming up). ...
What fuel pump you running, and how old is it?

Fuel pump is my guess based on your comments and the log you posted.
patsmx5 is offline   Reply With Quote
Old 04-06-2016, 07:35 PM   #13
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Did you check fuel pressure yet?

Do you have a vac leak?
Leafy is offline   Reply With Quote
Old 04-06-2016, 07:46 PM   #14
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

Quote:
Originally Posted by psyber_0ptix View Post
So i dropped into Rosenthal and bought a fuel filter anyway and changed it out. Topped off the tank too.

This log is after the 6th attempt to get it to start without stalling out. The log starts of just idling in the driveway then took it out around the block. I didn't want to drive too much on it.

I haven't plugged my computer up to the car for a long time so I don't know what would change between yesterday and today.
are you in Arlington during the day?
Braineack is offline   Reply With Quote
Old 04-06-2016, 07:53 PM   #15
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Unfortunately no, I'm in Bethesda. Though if you're willing to take a peak, I can leave a key somewhere among your favorite beer and a bunny. We have lots of rabbits in the area.

Just replaced the idle control valve as well. I want to say it's the fuel pump, only because I don't know any better.

Why can't I use an NA8 fuel pump in my NA6? Can I harvest the wiring from the Walbro? Is this real life?
psyber_0ptix is offline   Reply With Quote
Old 04-06-2016, 10:19 PM   #16
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

your MAT is showing 180F and your MAT corrections are pulling 20% fuel.

you need to make your MAT corrections flat at 100% across the table and replace your AIT sensor.




I may have a spare GM open element if I didn't give it to Lars, otherwise disconnect yours to drop the temp down to 70 which is the failsafe.

Try to recalibrate it first, seems really odd it's pegged like that.
Attached Thumbnails
All of the sudden leaning out everywhere-80-blob_336c6da0733076cec8d18a1da452cb376c5e21f0.png  
Braineack is offline   Reply With Quote
Old 04-06-2016, 11:05 PM   #17
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,199
Total Cats: 2,584
Default

probably shorted
18psi is offline   Reply With Quote
Old 04-07-2016, 09:14 AM   #18
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Holy crap. I'll take a look tonight. I hope it's not shorted, but if it where, perhaps unplugging wouldn't help and we'd know for sure.

I can pick this sensor up locally from parts stores I imagine?
psyber_0ptix is offline   Reply With Quote
Old 04-07-2016, 09:15 AM   #19
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Quote:
Originally Posted by psyber_0ptix View Post
Holy crap. I'll take a look tonight. I hope it's not shorted, but if it where, perhaps unplugging wouldn't help and we'd know for sure.

I can pick this sensor up locally from parts stores I imagine?
If you unplug it and it still says 180 then it's shorted in the wiring.
Leafy is offline   Reply With Quote
Old 04-07-2016, 09:48 AM   #20
Ich verstehe nur Bahnhof
Thread Starter
iTrader: (3)
 
psyber_0ptix's Avatar
 
Join Date: Mar 2012
Location: Northern VA
Posts: 3,713
Total Cats: 320
Default

Quote:
Originally Posted by Leafy View Post
If you unplug it and it still says 180 then it's shorted in the wiring.
My favorite demons. Thanks guys, I'll try this tonight. In the rain. Outside. On my muddy dirt way. Hopefully I can hobble this thing together again.
psyber_0ptix is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
1990 MSPNP AFR confusion?! confusedmx5 MSPNP 9 06-28-2016 12:48 AM
Tuning shop recommendations in Las Vegas? EpicOtter ECUs and Tuning 9 05-31-2016 02:35 PM
Low RPM signal, no spark macman2212 MEGAsquirt 16 04-10-2016 12:49 PM
Idle strangeness during warm up gregmiata MEGAsquirt 1 04-06-2016 08:18 PM
Finally Bit The Dust RAHNDEE General Miata Chat 4 04-05-2016 06:44 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 12:07 PM.