i have an 86 silverado 2wd 1/2 ton with a new 350 crate motor and a th350 tranny. it has an edelbrock 1406 600cfm carb. it will idle ok when it is in park or neutral but in drive or reverse the idle drops so low it will barely run and usually stalls out. i suspect a carb issue but it has just been rebuilt. could a modulator cause this? thanks for any help- robert.
sound like you load idle is to low. in park what you idle . When in drive it should idle @ around 550 RPM - 650 RPM as high as 650 RPM - 750 RPM depeneding on you motor in the truck. The info should be on your radsuport for the basic idle.
thanks for the reply. i didnt know the idle was supposed to drop so low. every automatic i have ever had idles around 1000 rpm in park. its probably at 1500 or 2000 in park right now. it does have headers on it so that could be tricking me, without a tach.
