Hi all I need some help for a 97 SC1. The engine runs fine good throttle response throughout the full range while sitting in the driveway but when driving and going to shift rpm climbs a couple hundred when the clutch is depressed going to second gear then will climb even more going into third. The high rpms won't come down until you basically stop the car just holding the clutch while rolling doesn't seem to help. I've cleaned the throttle body butterfly and shaft and I've removed and cleaned the IAC. It did seem to get worse after cleaning the IAC but I don't understand how that would affect engine performance between sitting still and driving. Thanks for any input.

 

I think some of that could be related to your Coolant Temperature Sensor and harness. Seems a lot of the idle problems are related to the CTS because of inaccurate readings and the PCM isn't sure that it's up to operating temp. I'm not a mechanic and I'm sure some of the other guys can tell you what to do.

 

Hi Rubehayseed thanks for replying! I should have also mentioned that the rpms are in the 2000 to 3500 range and that I sprayed all the upper vacuum hoses I can see with carb cleaner with no effect. While doing what I done so far I noticed a sensor (looks to be plastic? about 5/8" in diameter)on the left side of the head/block and that it's obviously been changed since the 2 wires coming from it have been butt sliced to the wires coming from the main harness. The butt splices are of the heat shrink/sealing style so I believe there would be no corrosion issues. Since I haven't as of yet found a good shop manual I'm not sure if this could be the ECTS I keep reading about.

 

I can't say for sure, but if you'll do a search, I'm pretty sure you'll find a lot of idling problems are related to the ETCS and the wiring harness that goes with it. If you can find a GM dealer in your area that still services Saturns, I'd recommend getting the parts there. Aftermarket vendors didn't seem to get these right for some reason.

 

That's what I've notice while doing a search. This weekend I'll replace the sensor and solder the connections. I also plan on changing the thermostat since I'll have the coolant drained. The car has 102000 miles on it so it's probably the original thermostat.

 

Let us know if that works out for you. My 95 SC1 has 296,000 miles on it now. The kid I got it from said the engine had been rebuilt while his mother-in-law owned it, but he didn't have a clue how many miles the rebuild had on it. It runs good, but I've got a slight slip in the transmission between 2nd and 3rd gear. A fluid and filter change did not help. I'm just needing it to last until this fall when I get a chance to replace it.

 

Will do. I managed to get a little time last night and took the car out for about 30 minutes. The temp guage didn't rise above the 1/4 mark and I ran it pretty hard so it's probably a good thing I was planning on changing the thermostat.

 

that low temp gauge reading may be the result of the ECTS having failed -- usually read low when they fail. get replacement and connector from a GM dealer

 

Thanks derf good to know. I placed the order for the sensor at the local chevy dealer and it's due in tomorrow night. I've started watching Ebay for a shop manual - I prefer the OEM because of past issues with discrepencies or lack of info in the others.

 

Be sure to replace the connector.