limige

when i reprogrammed my car i wanted to see what a lower idle would sound like. i set it at 875 rpm for both neutral and drive tables. (car is a 6 speed)

car idles at 950-1000 according to datamaster and shows 875 as the target rpm

why would it be idling so high? did i miss something??

mike

Injuneer

Is the coolant temp sensor input correct? That will affect idle speed. Is the VSS showing "0"? If it isn't, idle speed is elevated? Is the TPS showing "0%" and a closed throttle voltage less than 1.0V? Both those can elevate idle.

Is the IAC motor being commanded to close in response to the high idle? Is the IAC motor bottomed out at "0"?

limige

i'll check those out, i know for sure that the tps was at 0% i'll double check the rest when i get home

limige

ok
tps 0%
tps voltage .63
iac position 35

eng 78.5 deg C
oil 36.8 deg C

whats VSS?

MEAN LT1

Vehicle speed sensor

limige

OK, VSS is zero..

Injuneer

Seems odd..... the PCM should be lowering the IAC counts in order to pull the idle down to 875rpm. If the IAC counts are at 35, and the idle speed is high, should keep reducing the counts.

Is it possible you are reading the "learned IAC counts" rather than the commanded IAC counts? Your scan data will include both.

JPSartre12

Learned IAC counts? Which does Scanmaster LT-1 read?

limige

i'm using datamaster, i only remember seeing one listing for iac counts. it started at 51 and dropped down to about 35..

Injuneer

Scanmaster reads the commanded IAC position.
If its moving, its the commanded position. Datamaster will record a column for "IAC target counts"..... I believe.

limige

now this may be related but i just installed new injectors (syty) tried 55#pressure and tuned for 34.6# injectors..
bank 1 Long terms when up to 160 and bank 2 went to 135 or so..
raised the fuel pressure to 75# and bank 2 came down to 128 but bank 1 is still 157 or something.

other than a possible intake leak what could cause this?

JPSartre12

Thanks. My Scanmaster shows my commanded IAC position creeps up to 160 on idle when warm.

limige

found a couple of cracked hoses off the tb. fixed that and things got better, gotta get a new power invertor and do some new datalogs.