The compression looks good. No cylinder is supposed to be less than 100 and the lowest one should not be less than 70% of the highest.....which is 140. So I would think that would rule out the valves.
Having the wrong plug - make sure when you put the correct plugs in the gap should be 1.27mm or 0.050 in.
Since you will have that stuff apart, really look the plug boots....inspect really good. Put a little ignition grease in the boot. When you take the plugs out, really look at the ends that were in the cylinders and see if number 1 looks any different that the others. Compression is the same as 4 and higher than 2.......but still look really good.
Also, they have a technical service bulletin out on misfire, rough idle. When you have it apart really look to make sure the spring is there. I have attached the bulletin.
File In Section:
06 - Engine/Propulsion System
Rough Engine Idle, Misfire, Possible DTC P0300 (Replace Spark Plug Boot Assembly)
1999 Chevrolet Malibu
1999-2000 Chevrolet Cavalier
1999-2000 Oldsmobile Alero
1999-2000 Pontiac Grand Am, Sunfire
with 2.4 L Engine (VIN T - RPO LD9)
Some customers may comment on a rough engine idle and/or misfire. The Check Engine Light (CEL) may or may not be illuminated, and DTC P0300 may or may not be set under rough idle conditions.
Condition may be due to a missing spark plug boot spring.
(1) Spark Plug Boot Spring
Check for presence of the spark plug boot spring (1) by removing each boot and checking for spring presence at the boot to coil tower connection If the spring is missing, replace the spark plug boot assembly
Also there was a important note for the ICM cover bolts. Make sure you follow that. Install the Ignition Coil and Electronic Ignition Control Module assembly to the engine while carefully aligning the spark boots to the spark plug terminals. IMPORTANT: The ICM cover bolts must be installed with isolator washers with the rubber side facing down
You said you took the car to the mechanic...........are you able to do these things yourself or have to take it to someone? If you are using a mechanic, then have him do the fuel pump pressure check. I have attached a pic. It is an inline fuel pressure gauge.
FUEL PUMP PRESSURE
With the ignition switch "ON" and the fuel pump "RUNNING", the fuel pressure indicated by the fuel pressure gage should be:
With EGR 284-325 kPa (41-47 psi).
Without EGR 358-405 kPa (52-58 psi).
Once you change the plugs, see how it does. If it is still there, my earlier suggestion was to swap the number one fuel injector with another. Again, don't forget new O'rings with a little vaseline on them. Then make sure there is no codes, run it and check for codes and let's see how it does. It would be nice if the code jumped to the other cylinder. Then you would know the injector is bad.
Also the TRAC light - not to go too much into this right now but did it come on when you would floor it and then the car smoothed out for a little, or just normal driving......or when it starts to run rough......light comes on?
Here is some info on the TRAC light for your reading enjoyment though for now.
The amber TRAC OFF indicator will illuminate in order to alert the driver of an existing malfunction with the Enhanced Traction System (ETS). In this situation, enhanced traction will not be available. The ABS VI/ETS must be serviced in order to regain enhanced traction ability.
The amber LOW TRAC indicator illuminates in order to alert the driver when the ABS or ETS is active. Whenever the EBCM determines that the vehicle has entered a braking event that requires the ABS or an ETS event is occurring, the amber LOW TRAC indicator will turn ON. The amber LOW TRAC indicator will remain ON for approximately 3 to 4 seconds after the ABS/ETS event is completed.
The ABS VI with the ETS includes the following components:
" The ABS modulator/motor pack assembly
" An Electronic Brake Control Module (EBCM)
" Four wheel speed sensors
" An electronic brake control relay
" An ETS OFF switch
" An amber ABS warning indicator
" Amber TRAC OFF and LO TRAC warning indicators
" The interconnecting wiring
Okay Ted..........let us know............
Please consider a to help us answer more questions.
Thursday, October 23rd, 2008 AT 6:03 PM