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ISC-BPA Malfunction Symptoms
I was just wondering if anyone knows what a common symptom of a failure of the ISC-BPA on a 90-93 EFI Festiva might be? ... aside from the check engine light illuminating that is 
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1993 Festiva L - B3/Auto -
If it is working OK , the idle should be higher on a cold start up, and as it warms it will slow down ,or any load, like cooling fan or A/C comp cycling , it should raise the idle as it pulls a load on the engine to compensate the idle speed .------------------------------------------------
The Trigger - Midwest Festiva Inc., Illinois Chapter
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90 Festy L daily driver wants to be modded, OK
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OK assuming its working correctly. Which mine seems to be. Should it run all the time even with the key out of the ignition?Search Master - Honorary Member of Midwest Festiva Inc., Gulf Coast Chapter
Everyone is entitled to be stupid, but some abuse the privilege.
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I don't like superstitious people. They're bad luck. - Serge A. Storms
If at first you don't succeed, failure may be your style.
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^^ I have never seen one do that , actually run with the key out (ISC).
How long does it run , after it is shut off ?------------------------------------------------
The Trigger - Midwest Festiva Inc., Illinois Chapter
Smart Passion white with H-D interior
HD2500 Duramax Chevy
Harley Davidson Ultra classic ..I am in love !!
Pro Street S-10 http://www.cardomain.com/ride/2214968
Diamond white Deville 27,000 mile cream puff
Z28 LS1 power 500 +
90 Festy L daily driver wants to be modded, OK
It is being modded , a little at a time http://www.cardomain.com/ride/2214953
Join me on Facebook !! ;http://www.facebook.com/profile.php?...00000295094896Comment
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Until it kills the battery.Search Master - Honorary Member of Midwest Festiva Inc., Gulf Coast Chapter
Everyone is entitled to be stupid, but some abuse the privilege.
- Unknown
I don't like superstitious people. They're bad luck. - Serge A. Storms
If at first you don't succeed, failure may be your style.
- Quentin Crisp
God, please save me from your followers!
- Bumper StickerComment
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Could it result in a stall after initial warm up to operating temp? And then hard starting with a rough idle, or cranking with no start at all?
I'm experiencing an intermittent problem (As described) , checked timing,fuel system, tps,fusible links, airflow meter etc.
Replaced temp sending unit, fan thermoswitch, cap and rotor...
Dare I assume an ignition problem?
Doing my best to diagnose before replacing parts here all suggestions appreciated! Really miss driving the Festy!1993 Festiva L - B3/AutoComment
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Bump to hopefully get some answers.Search Master - Honorary Member of Midwest Festiva Inc., Gulf Coast Chapter
Everyone is entitled to be stupid, but some abuse the privilege.
- Unknown
I don't like superstitious people. They're bad luck. - Serge A. Storms
If at first you don't succeed, failure may be your style.
- Quentin Crisp
God, please save me from your followers!
- Bumper StickerComment
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Please?1993 Festiva L - B3/AutoComment
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I'm supprised that the ISC would directly cause a CE light....it is an output from the ECU....The only thing that I could imagine is low air flow would cause a rich mixture thus setting the O2 sensor. Normally the VAF would adjust the fuel mixtur for a sluggish ISC. If the ISC is malfunctioning...just a little trhottle would ease the problem
More likely for the rough idle....locate the idle/air bypass screw...not the throttle stop....turn the screw in slowly....count all the turns full in....the pull the screw all the way out. spray the circuit/porting out with some gumout...install the screw all the way in than and then turn out the previous number of turns.
CE light....best to extract code.Joe Lutz
The SKATE ..... 1992L 5spd
The Greatest Purchase I Ever MadeComment
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CEL : 02 and 081993 Festiva L - B3/AutoComment
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