my buddy has a 2005 cobalt ss with 60# injectors 2.8 pulley and all that. it has a bad idle when you start it up cold you have to hold the throttle some for a second or 2 to keep it going. there are no warm start issues at all. dont have a log of it. any help?
maf test.hpt
I'm having the exact same issue with mine, started after replacing the MAF sensor. After I get it figured out I will for sure let you know.
yeah we tried replacing the maf retune maf and all that and no differnce
bump any ideas anyone?
Bad injector or injectors? Every try doing a boost leak test?
the car runs fine and starts up fine when warm or warm out
Have you tried disabling the MAF sensor and starting the car in speed density mode? If I remember correctly you can set your MAF High Fail so that it will be trip DTC and disable then triggering the car to operate in speed density mode. This should eliminate the MAF feedback/regulation loop better than a sensor replacement. I notice you have the tune in the OP, could you try to get a log (I realize it will be difficult to get a log for that first couple seconds).
I have noticed some shady performance from Siemens 60# injectors on cold operation and low idles. They don't like to pulse accurately approaching their low limit.
2010 Camaro SS - Stock
2005 Cavalier L61 Supercharged - Sold
I'm not sure where you got your 60# Fuel injector data that you guys are using in the FUEL>GENERAL tab. You guys have modified Stoich, as well as told the car that the injectors are smaller than they are. Seeing a log could be very helpful.Originally Posted by 09cobalt 2.2
Are you guys seeing really rich LTFT's?
ignore that
Your Open Loop tables need enrichment for starts, you have the whole table set to 1.0, probably a result from tuning and not changing it back.
I recommend trying to create multiple files,
1 Maf, 1 VE, and 1 dd tune files at the very least. And even for tuning I would set the open loop tables to 1.0 only above like 150F coolant.
OPEN loop tables.PNG
I have run the same injectors in temps below freezing without ever having cold start issues. But in those temps my AFRs were starting around 11:1
He said his afr is like around 11.0-11.5. I need to log it some time and see. He said if he gives it a little throttle on cold start for a second or two and let off it idles fine. He also had an issue even before tuning and mods that the car would stall at a stop sign but I have yet been able to log that for some reason.
And I changed the cold areas of those to 1.28 but it didn't seem to help
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