Sputtery inconsistent idle

Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
My car has been dropping rpm's and sputtering/sometimes dying on occasion at stop lights or after accelerating.

As of today the issue is consistent and happens anytime after I give it gas. I had my camera with me so I recorded it.
http://s373.photobucket.com/albums/oo175/Bri7manx/supra/?action=view&current=P5050045.flv

SO I started it up again
http://s373.photobucket.com/albums/oo175/Bri7manx/supra/?action=view&current=P5050046.flv

After this it would not start and I was getting code 31, so I pulled the afm, let it cool to 75 deg F and measured its resistance at 1760ohms.
http://s373.photobucket.com/albums/oo175/Bri7manx/supra/?action=view&current=P5050047.flv

After this it took about 20 secs to start but it did so i got my camera and it acted just like before after starting. I replaced all my hoses as you can see they are new, could this be a boost leak?
http://s373.photobucket.com/albums/oo175/Bri7manx/supra/?action=view&current=P5050048.flv
 
gennro

gennro

New Member
Mar 12, 2008
357
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Alamogordo, NM
I have noticed 90% of the time the AFM will check out fine as per the TRSM but it still doesn't work. Also since you been having CPS problems check the wires in that area to make sure you didn't break anything. Plus 18 to 24 year old anything electronic will fail at some point.
 
Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
hvyman;1561649 said:
Does it start with the gas pedal fully depressed?
Click to expand...
yeah
adampecush;1561650 said:
does pulling a vac line make the problem worse?

I'm guessing vac leak...
Click to expand...
no just throttle, all my vac lines, accordian and hoses coming off of it are new
 
hvyman

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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Fullerton,CA
No it means to press all the way. Flattened. Nvm then.

Rough idle and hard starting thought it could be it but its still something to inspect.
 
Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
The last time it was hard starting like that was when I was trying to teach my sister to drive stick in the supra. She stalled it and it would not start for 30 minutes again. It started the same way it did earlier not in the vid but it took like a 15 second crank and barely caught on then started, started no prob after that.

I'm not sure if its related to the problem at hand or not.

---------- Post added at 03:11 PM ---------- Previous post was at 03:07 PM ----------

Forgot to add something.. Car backfires occasionally when decelerating while in gear, usually around 2-3k rpm's. It's a dull wha-pop-pop usually.
 
Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
Just finished buying everything needed to make a pressure controlled boost leak tester, hopefully it's a boost leak rather than something electrical, thanks for the help so far :)
 
Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
adampecush;1561910 said:
you check the timing?

did you change anything before this problem occurred or was it out of the blue?
Click to expand...
Yeah I set my timing on Monday to 10, I had it at 12 for a while.

The issue has been going on since a week after I rebuilt my engine so about 2-3 months ago, but ever so slightly. So at first maybe once a drive and up to the other day it was just a stumble say once a drive that a slight blip of the throttle would fix then today it just changed directions like a bipolar monkey.

I made this today:
sm_photo_missing.jpg


To check for boost leaks but never got around to using it because I was in question of the right way to do it, so tomorrow it will happen.
 
Bri7man

Bri7man

"Yeah! Take the lemons.."
Jul 17, 2009
580
0
0
35
Torrance, CA
I found a boost leak on the stock IC hardline that comes up by the intake. It's on the manufacture line where the plastic comes together.

I plugged it with my finger and revved but the car still would sputter and want to die every other rev after it returns to idle.

Also I unplugged the battery to reset codes after everything was hooked up and code 31 is showing again.

I checked my AFM per tsrm but I'm thinking like Gennro said, maybe it is bad even though it checks out per tsrm?
 
hvyman

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
12,568
1
0
Fullerton,CA
My buddy had 31(i think) one time when we were cruising around and it wouldnt rev. We swapped like 3 afms and same shit. Finally put his back in and tapped on it a little and has been good ever since. Didnt have a mm so we didnt check it. Afms are tricky little things.

Btw you can just pull the efi fuse for 30sec or more to reset instead of pulling the ground off the battery

Edit: I would just start going down this trouble tree and testing.
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=16

Afm is on the list but at the bottom. It really shouldn't effect idle as you usually can unplug it and it will idle perfect just wont rev.
 
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