BY U BOY

What would cause an 02 4.7L to not idle? When its cold and i take my foot off the gas it dies and to et it to restart i have to pump the gas.

After about 20miles of driving and i stop it acts fine.

my thoughts were a bad 02 sensor or an EGR.

bgchuby01

I am not a dodge mechanic but most engines have a cold temp sensor that will adjust the fuel mixture to help the engine run in cold weather

Ted G

You need an Idle air control valve. About 76 bucks at Autozone.

fabricator

Good possibility. Also could be a dirty throttle bore. When was it last cleaned?

BY U BOY

Well we put a code reader on it and found out it is a large leak in the emission system. Its going to be like finding a needle in a hay stack

BY U BOY

Thanks guys ill try some of the things yall have suggested.

mikes280

check the air tube from the air filter to engine and check for any vacum leaks

BY U BOY

I checked everything i could get to yesterday. Nothing out of the ordinary.

fabricator

A 'large evaporative leak' means there is a large leak in the fuel vapor recovery system. This will NOT cause your stalling problem. That code is most often caused by a missing or leaking gas cap.

mikes280

right, but a vacum leak may cause it and would be worse when cold. does that motor have a mass air, i can't remember but i thank it does. iac motor can be stuck also .