1997 Dodge Van Rough Idle only when started cold

WILCHAPPELL

MEMBER
1997 DODGE VAN
6 CYL
2WD
AUTOMATIC
101,000 MILES

Hi,
Running out of ideas. Idles very rough when started cold, idle is worse if it is colder outside when starting, runs great after warm up for 15 minutes, problem started after 4 month storage, no trouble codes, O2 sensors checked OK, IAC replaced but moves only slightly, restrict the air more and it idles correctly, no leaks on the intake manifold, acts like a partially open egr valve but I can't locate the egr valve - it should have one, new gas, battery OK, all new wires & spark plug and tune up last year at 100,000 miles and it ran fine then.
I'm sure that something simple is being missed and some sensor is screwed up.

2 Replies

MMPRINCE4000

MECHANIC
8,549 POSTS

The engine will run off a set program of fuel and spark until the O2 sensors and engine temp get to operating temp. You will not see much movement in the IAC during this period.

The EGR connects exhaust gas to the intake manifold, so look for a valve connected to both.
This vehicle also has an Exhaust Air Check Valve and an Exhaust Gas Recirculation (EGR) Valve Control Solenoid Filter. I would check both.
I would also clean the EGR base and pintle.

When you store a car (even 4 months) you should put some fuel stabilizer in it. You may have some injectors that are not sraying properly.