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96 Cheyanne 350 Vortec Super Rich at Idle?

Old Oct 11, 2010 | 7:04 PM
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Default 96 Cheyanne 350 Vortec Super Rich at Idle?

Guys...where do I start when diagnosing a super rich condition at idle...the engine has a miss too or it might be due to too much fuel. Some smoke is visible at idle and it misses in a way that it blows smoke rings sometimes! Pretty cool but killing my MPG....All ignition componments have been changed, I need to look at this thing from a point of how does the computer(also was replaced, either computer run exactly the same) decide what amount of fuel to dispense...please advise
Michael
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Old Oct 11, 2010 | 7:20 PM
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do you have a check engin light? if not, you proably have a lazy O2 sensor. get a program for your laptop, and loke at the O2 readings. (also can do a lot of other cool monitoring. I use http://www.obdcom.com it is $87 with the cord to connect to '96 and newer autos. works for what I am doing and can data log if you want to "play"
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Old Oct 11, 2010 | 8:34 PM
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Default great suggestion

Thats right up my alley...no CE light but i can say i replaced all 4 02s...and it got worse....I changed them all at once but im really curios to know what they are telling the CPU...will update...any more suggestions would be appreciated..i really dont know what I should be looking for...also a wild thought...wouldnt be catalitic related would it? no rotten egg smell..but sulfury
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Old Oct 12, 2010 | 4:26 PM
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sulfure smell? could be an issue, get the program, and set the data log to monitor O2 outputs, short term trim and long term trim. I'll look at mine and see what else we need to look at, and let you know
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Old Oct 12, 2010 | 5:34 PM
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Default ok

Ok..I ordered it and they sent me an email confirming shipment..cant wait!
MM
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Old Oct 12, 2010 | 6:56 PM
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the really cool thing once you understand the program, you can hook up to almost ALL '96 and newer autos, and diagnose CE light. can you say $$$ on the side
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Old Oct 14, 2010 | 8:06 PM
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Default Got the USB Scan tool- running rich...timing WAY off

Wow..this is cool..I posted a couple short videos, please take a look and offer any suggestion. For one thing...should the timing be around -20 etc? im sure not...then looks like one of the 4 02s not reacting normally...please take a look at comment back..thanks

http://www.youtube.com/watch?v=qLBQhPMkETM


http://www.youtube.com/watch?v=e1pdfd5CdAM

I know you can adjust the timing by the dist. on this model. Could it be possible Im off one tooth on the distrubuter? its a lot to be off assuming im shooting for 0.

thanks
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Old Oct 14, 2010 | 9:36 PM
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do not mess with the distributor, take that to a shop they have the tool to adjust it. set up to data log, save the file, then send it to me , i'll look at it. but looks like either you have a bad O2 sensor or a bad vacume leak on that side. Does it miss? you may have to drive it if you can. I'll PM you my email addres p.s. how do you like the program? kind of cool isnt it?
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