jumpy idle on cold start.

[ajan246]

Ok so i just replaced my thermostat, radiator hoses, and radiator (had a radiator explode on me and just did some insurance replacements) in my 97 HB truck. KA24E engine. While replacing the thermostat i had to take all the belts off so i replaced them as well. When I got it all back together i started her up and she runs and idles perfect in Park and Neutral, but when I throw it into R or D the idle starts JUMPING around from about 500RPM - 1100RPM and then it motor just dies on me. Any ideas on what could cause this? If i keep the engine reved at high rpm and warm it up for a few minutes it's fine and runs great! Could it be a too loose/too tight alternator belt? I'm stumped.

I also replaced distrib rotor,c ap and plugs.

Thanks!

[hardbody90]

mine was doing that a couple of days ago after replacing a throttle body gasket and i couldnt figuree it out.. turns out it was a vaccum line that was expose under the intake that i never saw.. so id just go over every line you took out.. recheck everything.. i dont think a tight belt would do that.. just my two cents.. peace man.. hope it works out..