I have a 1997 Saturn SL2, 1.9L, twin cam, A/T, 135k Mi.
The problem(s) are as follows:
Hard starting, once started, very erratic idle, frequent stalling. When the vehicle is in motion it runs fine except when you have to stop. When you stop, you have to " Pop" it up in " Neutral" and feather the Gas pedal just to keep it running, but when doing so, the " Tach" will jump up to about 4-5 k when in neutral. Once the vehicle reaches " Operating Temp" if you have to shut it off for whatever reason, you have to put the Gas Pedal all the way to the floor in order to re-start the engine. Although, at " Cruising" speeds.(40-65 mph.) The vehicle runs perfectly. Yes, the " Check engine" light does intermittently come on.
I have hooked the vehicle up to my OBDII scanner and here were the results:
1) O2 sensor voltage above acc. Limits. (Bank #1 sensor#2).
2) IAT sensor faulty.(Intake air temp).
3) Coolant temp. Sensor above temp reading.
4) #3 cyl. Spark plug voltage not registering.
I then went ahead and did a cyl. Comp. Test and the results were:
#1cyl.- 135 lbs.
#2cyl.- 145 lbs.
#3cyl.- 005 lbs. (At 4 different tries)
#4cyl.- 150 lbs.
And here were the condition of the plugs:
#1-Oil Soaked (not carboned)
#2-Fine, normal " carmel" colored
#3-Carbon fouled, but Gasoline Soaked
#4-Fine, normal " carmel" colored
Note: the plugs and wires have LESS than 50 mi. On them. And are installed correctly.
But what gets me is why the spark is NOT registering in #3 cyl. The " Coil Pack" was swapped out with another " Working" one, with the same results.
Could the Computer have a bad " Leg" in one of the sectors? Or, is it simply a, " Blown head Gasket"? These problems are Driving me NUTZ trying to properly diagnose them. ANY help from another Technition would be GREATLY appreciated!
Thursday, February 16th, 2006 AT 9:18 AM