I do take care of this car and iam on top of most thing but this one i dont know. it will just stop, everything will turn off. it will not start untill you let it cool off and the way you go, it will start right up not knowing how far you will get. i did replace the cps sensor and fuel relay and did try it out sunday,it went dead at the stop light. did order a cks sensor ,inline gas filter going to try that first be for i get the fuel pump checked. did put new plugs and coil packs in 30,000 miles ago. if any body got any ideal could use some help thanks

 

Ses light on? Any codes? Pls report as Pxxxx. Thanks.

 

no sen lights on and no codes? it only turn off when you are going down the road and you never know when that is going to be, so it is hard to try to get a code when it only does it at off times. let it cool down 15-20 min just like nothing wrong i just got a new cks sensor have not put that in let but will and try it again, i sure wish somebody out there had the same problem, that would sure help alot. keeping my car and finding what the problem is the main deal. thanks for the input if you hear of anything let me know

 

ok this is the 3rd time responding (fell asleep, interrupted)....

1) Yes you are making educated guesses but educated guessing and troubleshooting are not the same thing.
2) Your educated guessing is ruling things out at the cost of parts & time, both of which equal money, which is a very inefficient and expensive way to "fix" your car. I doubt you would accept a bill from a mechanic where he replaced 7 different parts to fix your one issue unless by definition they were all part of the same assembly

3) Anything that involves ignition, fuel, combustion and air is in play of course
a) combustion---would get a misfire code stored somewhere along the line
b) Air ---Air filter clean? How does it idle?
c) EGR--also "air" in a sense. I have had my EGR malfunction from carbon buildup such that the car would stall on it's own when decelerating, then wouldn't restart for 5 min, then would start again like nothing ever happened. Somehow did not set a code -- oh wait that was 95SC2 OBD I -- they had EGR codes but just basic ones.
d) Battery/Charging system--Are your battery and alternator connections tight and CLEAN? Are your battery and alternator cables crunchy from acid corrosion?

Step 1: Get the the charging system load tested at AutoBlows or similar -- it's FREE.
Rationale: Bad or failing diode in diode trio will cut your alt output by 33% Since the bridge rectifier is still good, you still see 14.4V at the output, but if the output current dips intermittently by 33%, it may not leave enough current to power the rest of the car (read:ECU and other computerized modules) Alt running in wounded mode likely not fully charging battery. Far fetched? A bit. Just throwing out food for thought.


Battery may have a marginal cell. Yes, alternator supplies current to run vehicle once running, but batt acts as capacitor to smooth things out. If alt cannot keep up with current needs, drain on battery begins until the V needed to run the ecu stops

However if this were the case, I would not expect you to be able to start it back up........

d) fuel: It is unlikely that a plugged fuel filter will unplug itself just sitting there
Fuel pumps tend to blip to zero and return to normal, or just flat out fail. Usually the latter. Only way to confirm it is to drive around w a scanner that captures real time data and watch the fuel pressure OR route a fuel pressure gauge to the fuel rail and run the hose between the hood and the windshield so that you have a real time indication of fuel pressure--not what the ECU SAYS it is

e) ignition : Host of possibilities.
You already swapped out coils
Ignition control module may be acting up and failing when hot. However, ,if you're on the highway I'd think it would be running cooler with the breeze across it. But if defective, its temperature tolerance may have shifted

OK:

Here are two straightforward tests you can do for free:

The next time the vehicle shuts down:

a) Hop out w a rag, cover the fuel pressure tester on the rail, then depress the center of the valve. If you have a nice stream of fuel, fuel is likely not the problem

b) Have your spark plug remover ratchet/extension socket rig with you. As soon as the vehicle stops, run out, pull a plug *gently*, leave it hooked up to the coil and plug wire on one end. Pull the fuel injector fuse. Ground the electrode tip against the block and have someone crank the engine over.

If it sparks, you know you've got spark in general. if you do not have spark, you have found the smoking gun, just not its owner.

Please post results of the above two tests and the charging system load test and we'll go from there

 

Could it possibly be related to the ignition switch? IDK, I'm just asking. You wouldn't happen to be one of those people with 3 or 4 pounds of keys on your key ring, are you?

 

derf, thanks for your input, i cant check the plugs if it stop. have to pull the upper intake off to get to them under the coil packs. if this next step doesnt work , then i will be takeing it down for a long check up on everything with somebody that knows what ther doing i hope, not going to try and try again cost money anytime.if you hear of anybody that is rerally good hear in las vegas let me know thanks

 

I dont know if it is related to the ignition switch idk but i do have alot of extral keys on my ring. thanks for your input

 

Nice catch, Rube. Don't know why I always leave that out of my analysis tree.

However, I would not think this is temp dependant.

Are you sure it is not time rather than temperature dependent?

You can still get the free charging system check and check for fuel at the rail......

 

My thinking on it since he's out in Vegas is some type of thermal expansion break in the switch, derf. Maybe the extra weight of all the keys is causing enough weight on the switch that once it gets hot, it loses connection? IDK Jaj105, why don't you try this for ONE day. Just take your ignition key off the key chain and use it alone in the switch. If it craps out on you, then you can probably cross that off the list of probabilities. I don't know what the hell else to tell you. Call several GM dealerships in the area and ask if any of them have a tech that's familiar with Saturns.

 

indeed. Some of the GM dealerships are now refusing to work on Saturns, prob due to parts availability and lack of knowledge