Hi.
If problem is only on startup and when idleing, then the
problem is likely IAC system, also a vacuum leak will cause the same
problem.
If problem is not only on startup and idle, but also when driving, then MAP sensor and EGR system must be checked.
Check also accelerator cable state and setting.
The
first thing to do is pulling out the OBDII fault codes stored in the
ECM. This is done connecting a code reader to the ECM diagnostic port.
The job can be done for a small fee at any local garage, and it is done
for free at AutoZone.
The codes will help locating the problem.
About possible faults:
Problem
is stalling when idling and during startup, but engine idling fast all
the time. Problem not starting at times it is due to the fact that the
wrong mixture is being sprayed, this is probably causing flooding and
misfire. Since the CEL is on, one of the codes returned is probably
misfire.
Check accelerator.
Check IAC system. This is
composed by a valve and a solenoid that check and control amount of
extra air air when the engine is idling. The IAC valve is located on top
of the throttle body.
Check the vacuum system and try cranking with gas tank cap off. Vacuum
system is tested using an hand tool gauge onvacuum lines while spraying
card cleaner on the hoses (or heating them with a torch). If there is a
leak, pressure will go up. A big leak will also do hissing noise, and
will often result in a lean code when doing an OBD code scanning.
This kind of symptoms can also be caused by weak wiring to MAP/MAF sensor (MAP in this engine).
If the car also drives very rough and is revving up and down in a weird way, check the EGR valve.
As
first thing I would do a code scanning. This car is OBDII. The scan can
be done for free at the nearest Autozone, or for a small fee at any
garage.
If you get any OBDII code from the scan, report it here, so that we can individuate the possible reason for the problem.
If
you repute my solution helpful, then please take some times to accept
the solution. Providing good repair tips requires time and skills, and
your feedback is important for us.
Regards.
Ginko.
