I've got a 1996 SL2 that had thebattery died. Replaced the battery, it died, replaced alternator and battery again. Now, when you start the car, the engine will idle at 2100 RPM and will not drop down to low idle even when warm. There are no codes, just a very high idle. Any ideas on what the problem is?


I need to get this car fixed for my daughter, it's getting a little old driving her to school and work each day.Edited by: Fireball69

 

Replaced the Engine Coolant Temp Sensor today and the car idled normally for about 30 seconds and then went back to idling around 2000 RPM. Sprayed TB cleaner all around looking for a leak around the intake but none found. Cleaned the TB and still idles high.


Any other ideas? I am throwing a Camshaft Positions Sensor #1 code still.

 

Did you also replace the ECTS connector? Corrosion here will hose the signal from a brand new sensor. Replace the connector with the Saturn replacement part.

Are you sure that all sensors were reconnected after the
alternator/battery swap and the throttle body cleaning? PCV valve
seated and hose re-connected to the air intake?

Might want to check the IAT (Intake Air Temp Sensor) -- should be located in the air intake tube either in the base of the air cleaner box or upstream of the filter (towards the front of the car). It may be disconnected or may be sending a bogus temp signal (that corresponds to the dead of winter in Wisconsin) to the PCM, causing the PCM to step up the idle .....though this usually sets an IAT code...

what is the cam code you're getting (Pxxxx?) cam codes are usually indicative of ingition related issues....






Edited by: derf

 

Did not replace the ETCS connector, it looks clean with no corrosion as did the connector on the old sensor. I replaced the Crankshaft Position Sensor today as that wascode the car had thrown before and would not reset. Also replaced the spark plugs. Old plugs were carboned up but dry.


Checked air intake sensor, it is connected and tight. How do you check other than visual?


Engine is still idling at 2000 RPM. No longer getting P0321 code. Engine is weak (no power). Any other ideas or things to check?

 

Engine is weak (no power). Any other ideas or things to check? </span>

This would suggest that you are not getting a spark to all four spark plugs. You could pull each plug wire off individually with the engine running to see if there is a difference in the idle and if there is spark. What I mean by pull off is really pull wire slightly away from the spark plug top. You will hear the spark jump if there is spark.
This doesn't address the high idle- like derf suggested, replace the wiring harness to the CTS. A Saturn only part approx. $38 Mine had no signs of corrosion, but was still causing the CTS to send a cold start signal to the PCM and that rich air/fuel mixture was causing a bad catalytic converter code to be set. It also caused the car to run rough because it has the same effect as applying a manual choke to an already warm engine. I hope you used the copper tip CTS.
This is a good thread for the CTS
http://www.saturnfans.com/forums/showthread.php?t=37884

 

I am throwing a Camshaft Positions Sensor #1 code still.</span>


Both P0340 and P0341 both relate to the Camshaft Position Sensor(I will
just call it Cam sensor from now on), the only problem is that the
S-Series engines don't have a Cam sensor, not a typical one at least.
instead, the DIS module watches when the #4 spark plug fires on the
compression cycle and fakes a Cam sensor signal from it. the tricky
part is that on a DIS waste spark system, spark plugs fire with their
mated cylinders(1/4 and 2/3 in 4 cylinder engines) every time the
cylinder is at TDC, regardless of weather the cylinder is on exhaust or
compression. However, it takes far more voltage to fire a spark plug on
the compression stroke then on the exhaust stroke, due to the
compressed air(more air molacules, more air the spark needs to jump,
more resistance to spark). The increased voltage needed on the
compression stroke is detected by the "#4 sensing circuit" inside the
DIS module for the Cam sensor signal. if the resistance of the
secondary system is not in the proper range or something else is
affecting the voltage draw, the "#4 sensing circuit" will be unable to
work properly.



In short, anything wrong with the ignition system, bad Cam sensor signal.
Edited by: paulorlo

 

I replaced the crankshaft position sensor (CPS) and have no more codes. I still have high idle and no power even at high idle due to a very rich mix. I will pop in a 300 ohm resistor in place of the connector for the ects and see if my RPMs drop to normal it does, then it's a bad connector, otherwise I would have to assume that it is something else.

 

I'm a bit confused now....your original post said "There are no codes, just a very high idle ". Your next post indicated "I am throwing a Camshaft Positions Sensor #1 code still" (which is odd for a car throwing no codes..(??)).

Your third post references P0321, which is:


DTC P0321 Ignition/Distributor Engine Speed Input Circuit Range/Performance.

Majority of Camshaft position sensor codes are P0340 to P0344.
Majority of Crankshaft position sensor codes are P0335 to P0339 and P0385 to P0389.

That having been said, I found a vague reference on the net that prompts you to change the Crank Position Sensor (CKP), which tracks the rotation of the crank and therefore indirectly provides a measure of the rotational speed of the engine. The CKP's (dirty) signal was probably interpreted as outside the range of normally expected output.

I'm surprised this cleared out the P0321 code. However, this did not fix the idle issue, so it is not the only issue.

Go to Saturn, lay out the $40 for a new ECTS connector, and let us know--if it doesn't work, we'll continue to troubleshoot.

-----

IAT Sensor Sensor Resistance ranges for testing:
212 F (100 C) 177 OHMS:
-40 F (-40 C) 100,700 OHMS

Also -- have you checked the PCM input for the ECTS to ensure the wiring is intact/in good shape?

Derf

 

Just remembered a quick test I did on the CTS when I suspected it was making intermittant contact, since I had replaced the sensor but not the wiring harness. Remove the sensor wire cap and spray the cap with PB Blaster. It is a penitrating catalyst that is also compatible with electrical parts. Replace the cap and start the motor. Allow the motor to warm up and with it still running apply a downward pressure to the cap on the CTS if the idle changes, you have found your culprit.

 

My error(fat fingers) [img]smileys/smiley9.gif[/img]. The code the car was throwing was a P0341 (crank #1). The code has been an ittermittent code since we bought the car last year. It has alway reset and normally occured oly when you attempted to start the car and it didn't. i.e. let go of ignition switch too fast or meant to put switch in ACCY and went too far into start position.


I did change the crankshaft sensor on Sunday after I was getting a constant code that would not change. The code resets now but there waschange in idle speed, still high.


Today checked all vacuum lines again and the PCV valve, and made sure all wire were connected and lock into position. Car started and idledabout 1200 RPM. Took it for a test drive. Engine is strong [img]smileys/smiley4.gif[/img]except transmission is slipping in first gear now.[img]smileys/smiley19.gif[/img]


Drained transmission and replaced filter. Need to fill transmission in morning and take for a drive to see if that helped. We've put on about 30,000 miles since we bought it and don't know when trans fluid was changed last. Fluid was a little dark and smelt a little burnt.


Do you think trans will survive or will I need to get rebuilt?