Mechanics

DROPPING RPMS AND WONT START AFTER HEATING

1996 Saturn SC2

Engine Performance problem
1996 Saturn SC2 4 cyl Front Wheel Drive Manual

I have a Saturn sc2 1996 it is dropping RPM's every once in a while. I was told it was the fuel filter so I changed it, Still dropped RPM's then I was told it was the coil packs I replaced them and then throttle position sensor, crank shift position senor, catalytic converter and map sensor I replaced all these items and it still happening and now when I start the car it starts up fine but when I shut it off the battery dies after about 3 hours I can start the car again. I don't know what more I can do can anyone help me?
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Bonniehann
July 31, 2010.



First of all thank you so much for your donation. Let's start with you going to a auto part's store like auto zone and having your code's read. Let me know what the number's are if you have any code's. The coil pack's hardly ever fail I mostly replace the coil's because the coil tower's get corroded on that year. The throttle position sensor hardly ever fails can't remember the last one I replaced even. Crank shaft position sensor hardly ever fail's on that year it's mostly on the 1998 and higher year's that the fail. The cat's do get clogged and have to be replaced on those. The map sensor's hardly ever fail as well the last one I replaced was years ago. So when you say it drops rpm's do you mean it misses?If so is this at idle or while driving when the car is under a load?Also have you checked your spark plug's for being worn or black residue on them where they meet the wire's. Also have you checked your spark plug wire's they could be breaking down internally. Now let's talk about your car get's hot and won't start for three hour's?You also said something about the battery dieing?So when it doesn't start for three hour's what happens when you try to start it?Does it crank no start or no crank no start?If it's a no crank no start can you even hear the starter click?Also do you have a multimeter to do some testing?

Saturntech9
Jul 31, 2010.
As far as the spark plugs and wires they have been replaced. What is happening is as I drive she will run great as long as I am on the highway but once she gets into the city the RPM's drop between 10 -0 she does stall I have to hit the peddle and she goes back to running normal for a while. As for the starting of the car it starts fine but once she reaches temp and I stop to turn it off to go into a store when I come out I need to jump her and some times jumping won't work it just clicks. This problem came to happening after the starter was moved to make room to get to the crank shaft position sensor. Oh I almost forgot I had the cars codes read 8 times each time it says cam shaft position sensor but I was told this year car doesn't have one the engine light goes on and off after a few days.

Tiny
Bonniehann
Jul 31, 2010.
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http://www.2carpros.com/forum/automotive_pictures/416332_1996_sc2_spark_plug_wire_1.jpg


On your starting concern have you checked and made sure your battery cable's are clean and tight?Also have you had your battery and alternator tested?Have you made sure that all the connection's to the starter are tight you said you moved the starter so i would check all those connection's.Also what kind of plug's did you put in?When you replaced the wire's are you sure they were routed correctly?I would check those for sure.Also another thing that fails a lot on those cars is the coolant temp sensor there only 10.If you replace it make sure you get a brass tipped one the plastic tipped one's crack.Also inspect the connector going to it if it's corroded then you will have to replace the connector.On the diagram i posted the big one is the engine and the little one is the coil all you have to do is match up 1 to 1 2 to 2 3 to 3 and 4 to 4.All so can you get me that code number that keep's setting

Saturntech9
Jul 31, 2010.
I have cleaned the battery terminals and replaced them as well, as for the spark plugs the book said to place copper spark plugs so we have done that we checked on the plugs and everything looks good there. My wires were place correct. I have had my battery and alternator checked they checked in fine. I will go and check the coolant temp sensor next. Wish me luck ! I will go and get a reading for the code again I think it was 2902 but not sure I will recheck that

Tiny
Bonniehann
Aug 1, 2010.
Alright good luck let me know what you find.

Saturntech9
Aug 1, 2010.
I was thinking last night. Could the reason for the RPM dropping or the car not starting after it heats up be from the fuel solenoid? Does my car have one?

Tiny
Bonniehann
Aug 2, 2010.
Fuel solenoid?You said when your car doesn't it just click's i'm thinking bad starter or loose connection. Don't forget to check out that coolant temp sensor and the connector going to it being corroded. Also check and see what code's you have. Do you have a multimeter we can trace power with?

Saturntech9
Aug 2, 2010.