Subject	I like the Conzult Display
Posted by	Cjw3 on October 12, 2022 at 9:38 AM
	This message has been viewed 227 times.
In Reply To	Re: Do a Cylinder Idle RPM Drop Test. posted by 90Z_NA_Auto on October 11, 2022 at 08:37 PM
Message	It looks from the O2 Sensors, that you are idling a little rich.. Perfect is .4, Lean is .2 rich is .6.. Rich is 'Somewhat Normal' for a '90NA, as the Idle Set up is really screwed on the 300 With the IAV's.. ( Blowes Air into the Exhaust during Idle to keep the Cats Lit, and it needs a rich mixture to do that ) If you look at the Left O2 Sensor, It's Rich (.8Volt ) and it 'Bumps Down' a little when the Miss-Stumble happens.. That is a bump toward the leaner side, which happens when the Fuel does not burn, and the O2 Sensor just sees the Air and raw fuel from that Cylinder. The way I would fix this is to 'Chip' the ECU and put a little tuned chip into it.. It will help with Performance and Fuel Millage.. Tuned chips do not have to deal with the IAV's, and will pass all tail pipe sniff smog tests.. However, your Question, how to fix this.. Check fuel pressure at Idle.. if the Pressure Regulator is running high at Idle, then the Mixture Control ( which is Horrible at Idle ) will not be able to correct. Or Find a '94 NA Auto ECU.. they will run leaner at Idle, as they do not have IAV's to deal with.. It will Plug right in.. and it's always good to have a Back Up Spare of the Electronics.. Cj
Follow Ups	Idle Troubleshooting - 90Z_NA_Auto 18:17:28 10/11/22 Do a Cylinder Idle RPM Drop Test. - Cjw3 20:12:50 10/11/22 Re: Do a Cylinder Idle RPM Drop Test. - 90Z_NA_Auto 20:37:19 10/11/22 I like the Conzult Display - Cjw3 09:38:03 10/12/22
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