just finished doing a full build, and currently kept stock injectors just for breakin period, and to become more familiar with tuning stock ecu before i do anything too drastic.

Have been making basic changes but right now the car will start fine begin to idle at a reasonable afr, but then slowly drops to 10.0 afr, as car warms up it will lean out slightly but maybe to a 11.2ish. Not sure why, i tried changing the % in the open loop tables but it made no difference bypassing it. If i give it a few quick blips in the throttle it will rev up fine, but sometimes wont catch its self and rpm's will drop very low/stumble, and could stall. i've brought up the idle to 1000, and brought the ign timing to 7* and kept the 0/0 cell at 5*. In evoscan the fuel trims are at 0 as well.

p&p head, kelford 272's (ix), 35r, 93oct

any help would be appreciated

 

Are your inj scalings and latencies in your tune right now for the stock injectors? Or are they for your larger injectors, but your using your stock injectors?

Nevermind.

 

Stock injectors, stock scaling. Did more of a full cold start to warm up log today. Was still pretty rich until the car was up to operating temperature. At that point the fuel trim started going down (negative) and then stopped at -12.5 and still would idle at 13 afr. A few times through warm up the car would stumble/studder and I gave it gas quick to clear it up but rpms hung a little and would then fall hesitate to idle good again.

 

New o2 sensor? If not, it could be going bad....

 

well it didnt really change when i forced open/closed loop running. So with or without going off the front 02 no changed happened....

 

any help?

 

Forced open loop will pretty much do the same thing as a dead front o2

 

check for leaks in the charge pipes.

 

Went over all my pipes, checked for vacuum leaks still nothing. I let the car do a full warm up again and I was watching the trims. Oxygen feedback trim (stft) was always -xx.xx. ltft were 0 until the car was coming up to operating temps then ffuel trim mid (ltft) started to pull negative stopping at -12.5. The stft still in negatives would dip to 0 and I could feel it in the car and idle smooths out as that began to go negative again. (I have full log of this if anyone is that interested in helping)

 

many people tells me that they checked the vaccum and charge pipes until they make a leak test and change their mind,send me a log please from 0 trims till it starts to fall down,but does this happens at cold start or fully warmed up situations ?,,what do you mean when you said it didn't catch itself ? you mean it doesnt rev up till redline at neutral gear ? does that happens when the trims and 0 too ? or only at -12 ?

 

when you forced to full time open loop did you try to lean it out at low load ? is your maff clean ?