missfire, stalling out

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
ive had this problem for a while but i just thought it was a tuning issue as a resuld of a clogged cat and it still might but im running an unrestricted exhaust no cats. anyway at idel car sounds like its missfiring and sometimes even stalls. i checked timing that was ok TPS is ok spark plugs are new but checked them anyway and appeared to be ok. can anyone offer any insite im lost. oh and i noticed at idel car goes way rich like 10.2 but not all the time
 

mkIIIman089

Supramania Contributor
Mar 30, 2005
3,061
0
36
Ohio
51 Switch Signal


Diagnosis

* No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.

Trouble Area

* A/C switch circuit
* A/C switch
* A/C amplifier
* Throttle position sensor circuit
* Throttle position sensor

* ECU
 

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
mkIIIman089 said:
51 Switch Signal


Diagnosis

* No "IDL" signal, "NSW" signal or "A/C" signal to ECU, during diagnosis check.

Trouble Area

* A/C switch circuit
* A/C switch
* A/C amplifier
* Throttle position sensor circuit
* Throttle position sensor

* ECU
i measured the resistance on the throttle position sensor and it came back normal.
 

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
mkIIIman089 said:
Welp, any vacuum leaks or big holes in the IC piping?
nope vac on my guage reads ~10 in hg. and checked around the manifold for leaks and nada. ill check the ic and report back but i dont think ill find anything its in tip top condition.
 

mkIIIman089

Supramania Contributor
Mar 30, 2005
3,061
0
36
Ohio
Well, my best guess would be the TPS or something causing the AFM to send an incorrect reading.

Mods?
 

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
mkIIIman089 said:
Well, my best guess would be the TPS or something causing the AFM to send an incorrect reading.

Mods?
map-ecu, megan racing downpipe, custom cat back exhaust, hks bov, horsepower freaks intercooler, ct-26 with 57trim.
 

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
Nick M said:
10 inches of vacuum indicates a vacuum leak, or horribly weak engine.
i got the reading off my boost/vac gauge.
and i was a little off its closer to 15
 

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Nick M

Black Rifles Matter
Sep 9, 2005
8,894
38
48
U.S.
www.ebay.com
In Denver (I didn't even notice that part ::dunce::) that is close to normal.

Does the air fuel ratio constatly roll, or is it just sometimes that it moves?
 

F_T_F

C2H5OH
Nov 12, 2006
255
0
0
fort fun, colorado
Nick M said:
In Denver (I didn't even notice that part ::dunce::) that is close to normal.

Does the air fuel ratio constatly roll, or is it just sometimes that it moves?
for the most part at idle it stays around 18 but sometimes it drops down to 10 and will idle at 500rpm then sputter and die. if i rev my engine up to 5000rpms or so that seems to correct the problem but its annoying having to rev it up at every freaking stop light just to keep the car from stalling out. i cant seem think of any other relevant information.