lt1 first start, wont stay idleing by its self

[Coreylt1]

just started my car yesterday for the first time, it wont start unless if its given some throttle, and it will not idle by itself.

i do not have oxygen sensors in it yet

its tuned for 24lb injectors and i have 30 lb injectors in it.

could it have anything to do with the throttle body and the hoses that go to it? im not sure about a few of them, and cant find a diagram of how its suppose to be



thanks

[sweetbmxrider]

Yes, all of those things can affect it. The o2's don't kick in for a little bit though so not them so much. Is it cammed? You should have it tuned for any and all mods you have otherwise you'll be fighting to make it run. You can try an IAC reset, turn the key on with engine off while holding the gas pedal halfway down for 10 seconds.

Being its a fresh build, you might just have to milk the gas pedal a little bit until the computer learns idle, spark and fuel tables, and whatnot.

Just saw your video, sounds good. If you aren't tuned for the 306, its not going to idle on a stock tune.

[Coreylt1]

Originally Posted by sweetbmxrider

Yes, all of those things can affect it. The o2's don't kick in for a little bit though so not them so much. Is it cammed? You should have it tuned for any and all mods you have otherwise you'll be fighting to make it run. You can try an IAC reset, turn the key on with engine off while holding the gas pedal halfway down for 10 seconds.

Being its a fresh build, you might just have to milk the gas pedal a little bit until the computer learns idle, spark and fuel tables, and whatnot.

Just saw your video, sounds good. If you aren't tuned for the 306, its not going to idle on a stock tune.

i plugged in my obd2 scanner, brought up codes for MAF and TPS.

whats the most effective way to troubleshoot for this?

[sinistr]

a voltmeter for your tps , it should be around .5 at idle then like 5.xx at wot . i believe its the gray and blue wire but im not sure , the maf im not familiar with

[sweetbmxrider]

Post up the code numbers. MAF should not matter. You will most likely have to slot the tps mounting holes to get the correct voltage.

Originally Posted by sinistr

a voltmeter for your tps , it should be around .5 at idle then like 5.xx at wot . i believe its the gray and blue wire but im not sure , the maf im not familiar with

Most say to go with .67 with throttle closed and wot is registered over 4.5 volts.

[Coreylt1]

Originally Posted by sweetbmxrider

Post up the code numbers. MAF should not matter. You will most likely have to slot the tps mounting holes to get the correct voltage.



Most say to go with .67 with throttle closed and wot is registered over 4.5 volts.

set it to exactly .67
took off the tb and i plugged in the tps and the iac and if both are working properly then i should be able to open the throttle and watch the iac move , correct?

[sweetbmxrider]

The IAC is used to maintain idle. Opening and closing the throttle body really won't show you much. You best bet is to use a scan tool that has the ability to display datastream. You want to watch IAC counts. 30-40 counts is desirable for hot idle. 160 is maxed out and means you'll have idling troubles. You want to drive the car and watch what they do when you come to a stop as well.

[Coreylt1]

Originally Posted by sweetbmxrider

The IAC is used to maintain idle. Opening and closing the throttle body really won't show you much. You best bet is to use a scan tool that has the ability to display datastream. You want to watch IAC counts. 30-40 counts is desirable for hot idle. 160 is maxed out and means you'll have idling troubles. You want to drive the car and watch what they do when you come to a stop as well.

what is the best scan tool for these cars? i only have a craftsman code reader, so im in need of something decent

[sweetbmxrider]

Anything that will support datastream will be fine