Anyone have any ideas as to why my car keeps doing this???
09-10-2004, 03:36 PM
#1
Anyone have any ideas as to why my car keeps doing this??? Its a 408 Stroker with mods in sig and has about 7000 miles on it I guess. What it does is when you first start it it runs really rough and spits and sputters and smokes a little, smells like it is running rich. If you try and drive it doesnt want to go and hesitates and pops. Now once the car warms up it doesnt do it anymore at all, only when its cold. Also my SES light is on and keeps giving my insufficient switching banks 1 and 2. My SES light will also flash if I sit in traffic and stop when I start moving. When I am sitting still it smells like it is running rich. If I go out and really lay into it it will blow out a BUNCH of carbon the first time and then anytime after that I get into the pedal it doesnt, like its loading up. I have replaced the 02 sensors and the plugs are fairly new as well. This problem started not too long ago and has seemed to have gotten worse as time has gone on. Any ideas would be appreciated!!
09-10-2004, 05:40 PM
#3
Originally Posted by Yelo
Sounds like a fuel problem to me......have you maybe cracked an injector or are the cats clogged to the point that the motor starts loading up ???
Could be an injector issue I guess. I have no cats so it cant be that.
09-10-2004, 05:41 PM
#4
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I have a feeling he doesnt have cats?...maybe im wrong, but if I had a 408 stroker, I wouldnt want any cat cloggin up my exhaust...as for your problem, I couldnt give you an exact answer, but my buddy had a somewhat simmilar problem with the smoke and all and he needs new valve seals. This is second hand information so im not sure, just an option though.
09-11-2004, 01:40 AM
#5
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The insufficient switching is probably due to the headers. You may need to grind the O2 bungs down some to allow the sensor to get into the exhaust stream a little more. With insufficient switching,the PCM isnt going to be fueling the car correctly. You need to ATAP the car and find out which cylinder(s) are misfiring and get that taken care of first.
09-11-2004, 09:17 AM
#6
Originally Posted by MyLS1Hauls
The insufficient switching is probably due to the headers. You may need to grind the O2 bungs down some to allow the sensor to get into the exhaust stream a little more. With insufficient switching,the PCM isnt going to be fueling the car correctly. You need to ATAP the car and find out which cylinder(s) are misfiring and get that taken care of first.
Could it also be that the tuner tuned the car to run lean at idle to try and help it pass a sniffer test?? I am hoping that is all that code is.
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09-11-2004, 03:55 PM
#8
Originally Posted by Dustin Butts
Engine coolant temp sensor? Did it get damaged or maybe it isn't working...?
No that is alright and working. We Auto tapped it today and all of the codes were insufficient switching bank 1 sensor 1 and bank 2 sensor 1 except one. That code was heater circuit for I believe bank 1. Now the funny part is while we were checking it the SES light started flashing so we checked for codes and there werent any.
It wasnt showing a misfire or anything, we revved it a little and it went out. Ity never showed a code while it was doing it. What gives??? What could cause the SES light to flash but not throw codes??
09-11-2004, 06:15 PM
#10
Originally Posted by Dustin Butts
I really think you need to get with Brent and let him do some more in depth tuning.
I am but I am trying to wait until I get my stand alone fuel system on and have my 200 shot on it. That way I cant get it tuned for that while I am there.
09-11-2004, 06:40 PM
#11
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Yeah if it only does it when it's cold and it's not the ECT sensor, and you just replaced the O2's...it's gotta be in the tuning somewhere. I am by no means a tuning expert but that's what it sounds like to me.
09-13-2004, 12:12 PM
#13
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ECT: Engine Coolant Temp sensor. Located in the drivers side head near #1 exhaust pipe.
According to the GM manual: The PCM applies 5.0 volts to the sensor. When cold the sensor feeds back high resistance. When warm, low resistance.
According to the GM manual: The PCM applies 5.0 volts to the sensor. When cold the sensor feeds back high resistance. When warm, low resistance.
09-13-2004, 01:00 PM
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I had the same issue and it was an 02 harness issue, SES light flashing means misfire
I noticed on my scanmaster and my a/f guage that the o2 was pegged at .999 all the time, I checked and found a broken o2 extender harness, replaced and all was well.
I noticed on my scanmaster and my a/f guage that the o2 was pegged at .999 all the time, I checked and found a broken o2 extender harness, replaced and all was well.