how to speed up idle.

[felskee]

i recently got my engine rebuilt 500 miles ago and it still idles around 500 rpm. which is bad because the voltages are are around 13 v.

 

[AtomicHoe094]

can you put an over drive pulley on the alt? Might be something in the computer?

 

[felskee]

it would have to be somthing with the computer id imangine... but i still does needa idle higher cause my engine runs hotter cause the waterpump isnt running fast enough. how could i fix the computer?

 

[SunlitComet]

programming the PCM. Blackbear Performance can do that for you. I would wait until you are broken in if you can wait and get a tune and have that changed as well. Double wahoo.

 

[felskee]

well i already racked up 500 miles. changed the oil. soooo its time for the tune i guess

 

[SunlitComet]

Maybe have your vehicle scanned and make sure the live rpm the scanner has match the tach in the cab first.

 

[felskee]

but when i stop at a stop light my volts go fro 14+ to 13's and theyve nevr done that

 

[gpracer1]

but when i stop at a stop light my volts go fro 14+ to 13's and theyve nevr done that

Just wait till you have the front and rear AC blowers on high, have your headlights on, are sitting at a light in drive with the brakes/brake lights on and you are reading 11.9-12.3

Thats when I got a 140 amp alt from an LT with heated seats and put a super small pulley on it....problems solved.

 

[SunlitComet]

but when i stop at a stop light my volts go fro 14+ to 13's and theyve nevr done that

I under stand that but if you PCM is interpreting a high rpm from a screwy crank sensor it may slow down the engine thinking it is at about 625-675 but in reality it is much slower. Maybe not really happening but worth checking at least since you have had the engine assembly apart. Computer speed is determined by crank. Tach is determined by spark.