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2002 Saturn hard start and high RPM


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comnavguy
User

Jun 2, 2009, 12:51 PM

Post #1 of 8 (6467 views)
  post locked   2002 Saturn hard start and high RPM  

2002 Saturn SL 1.9 engine. 5-Speed tranny. 172,000 miles

Car is very hard to start and runs rough at first. After a few minutes it runs smoothly but at 1200 RPM with the A/C off. With the A/C on, the RPM drops to 1100. How is RPM adjusted?

It just failed emission test: No fault codes but; Catalyst "Not ready"; Evap "Not Ready"; O2 Sens "Not Ready"; EGR "Not Ready".

I disconnected the battery for 10 minutes and have re-connected it and driven for 20 miles. According to my Actron CP 9135 there are no fault codes and all monitors are ready NOW, but that was the case before I took it in for it's annual a week ago. I get one re-check free, and then it's another $40.

What would cause those sensors to be "Not Ready"? and how to adjust the RPMs?

ALSO - The water temp gauge just stopped working. Needle is below C. Where is the water temp sensor on this car and is it one wire or two?


Loren Champlain Sr
Veteran / Moderator
Loren Champlain Sr profile image

Jun 2, 2009, 3:35 PM

Post #2 of 8 (6458 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

comnavguy; There are two sensors; One for the guage (single wire) and one for the PCM (two wire). If the PCM 'thinks' the engine is cold it may not be going into closed loop operation, and running too rich. That could account for the fast idle speed, as well. Every time you disconnect the battery, the monitors have to go through a re-learn process. There is actually a drive cycle process for this, but usually, just driving it at normal, varying, speeds works. Sometimes, 20-30 miles. Generally, the EVAP and Catalyst are the last ones to complete. Fill the gas tank to between 1/2 and 3/4 tank. No more, no less. That will help the EVAP monitor to complete more quickly. Needs some, but not too much, air space in the tank.
The engine idle speed is controlled by the IAC (idle air control) motor which gets it's information from the PCM, which gets it's information from the various sensors. If the thermostat is missing or stuck in the open position, the engine may not be reaching operating temp (200-220F).
Loren
SW Washington


comnavguy
User

Jun 3, 2009, 3:49 PM

Post #3 of 8 (6446 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

Thanks, Loren,

I followed your suggestions and the vehicle passed inspection about 2 hours ago. The idle is still high and the temp gauge needle is sitting on the low peg.

I have to believe the water temp sensor is bad or the lead has been disconnected.

I have been told that the thermostat is on the passenger side at the outlet port of the water pump and that the sensor is located on the top of the engine on the driver's side close to the top hose from the radiator. Can you (OR ANYONE) confirm that ?

Thanks much for the help.


Loren Champlain Sr
Veteran / Moderator
Loren Champlain Sr profile image

Jun 3, 2009, 4:08 PM

Post #4 of 8 (6444 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

Yes, the thermostat is where the lower radiator hose connects to the engine. The coolant temp sensor is at the rear of the cylinder head, near the upper radiator hose.

Looks like this vehicle uses one sending unit for both the guage and the PCM. The one shown is for the SOHC engine.
Loren
SW Washington


comnavguy
User

Jun 4, 2009, 10:29 PM

Post #5 of 8 (6435 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

I'm going to replace the temp sensor. The RPM was high before the temp needle was resting on the bottom stop.

If, when I replace the sensor, the RPM is still high, what do you (or anyone) suggest is my next step ?


Loren Champlain Sr
Veteran / Moderator
Loren Champlain Sr profile image

Jun 5, 2009, 3:02 PM

Post #6 of 8 (6429 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

comnavguy; Look and listen for any possible vacuum leaks. Clean the IAC and the throttle body, if you haven't already.
Loren
SW Washington


pjmncccn
New User

Jan 17, 2011, 11:49 AM

Post #7 of 8 (5476 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

Common problem with Saturns. Replace coolent temp sensor and Theromstate. The computer isn't getting the correct temp feedback to perform a reset.. easy job- takes about 30 minutes and around $20.00. check I/M status with an OBDII reader. Most Autozones (outside of CA) will let you use a reader.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Jan 17, 2011, 12:16 PM

Post #8 of 8 (5472 views)
  post locked   Re: 2002 Saturn hard start and high RPM  

pjmncccn

This post is over 2 years old. Please check the dates before posting.




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