2003 sunfire 2.2 ecotec won't start.

Car ran fine, all of a sudden it stalled with no warning, leaving us stranded 30 miles from home Would not re-start at all, cranks and cranks but won't start. Got the car towed home and am now trying to figure it out.

Here's what I know so far, to no avail:

-fuel pump primes when key is turned on
-all fuses are intact, nothing blown
-fuel pump relay clicks when key is turned on, working normally
-replaced ignition coil (or whatever its called that sits on top of the spark plug boots)
-replaced ignition control module (ignition cassette, whatever, the thing on top of the previous item)
-no security light on (ie. it's not passlock)
-no codes found with a scantool
-tried wiggling wires that go into the BCM as i read in a previous thread, no change.
-tried checking the fuel pressure, fuel sprayed all over when i pushed the valve on the fuel line
-cleaned up small ground wire on top transmission bolt, as i read in a previous thread, no change.

I am at my wits end. Talked to two different mechanics, who suggested nothing that i haven't already tried. Why would this car just turn off for no reason and never start again??!?!?!?!? PLEASE HELP


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98 Z24 5-speed

do a compression check. where there any strange noises right before this happened?

no strange noises, sounded just like it would have if you turned the key off.

i am 99% sure this is some sort of electrical problem.


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98 Z24 5-speed

When it cranks does it crank faster than it usually does ? Could be a broken timing chain. Get a spark plug tool and see if you are getting spark, could have saved $200 if you'd bought the $15 tool instead of the ignition parts. Next take your scan tool and make sure your Crank Position Sensor is working, that will cause it not to run. Let us know if you have spark, then let us know if you have a good CPS signal, if those don't help then let us know if you hit anything on the road before it happened, If you hear any different noises from the engine when you try to start it, and we'll try from there.

Pull the battery and have it tested. Example on our show car the battery has had its share of stress over her 5 years of service and age finnaly caught up to it. I cant start the car just cranks. I hit it with our shops starter and fires up. as soon as i turn off useless again. guages and all accessories work fine.just not enough crank amps to turn over. new battery Good to go. also i would take the few minutes to go under the car and remove the starter simple 4 bolts and have that checked as well. i just did a swap on my buddies avalanche and his truck was hit or miss starting. it would crank n crank but not enough output to spin the speed range needed to turn over. your looking at less then 20 mins to pull ur battery and starter plus time to go to auto store and have tested. at least worst case youll have a better peice of mind knowing u can rule them out and also did i mention the tests are FREE lol. idk how far u are from a advance or auto zone or pepboys but worth a shot. also based on my past expericance is your belt on the side intact? my tentioner snapped last year and i lost my belt. soon as i took my foot off the gas it died i was able to get her home but id look there too. like i said this is just based on my experiance and these are also all free quick checks. good luck hope u get it working again.

When your battery went bad but still turned over the engine do you know if it was still reading over 12 volts or not. I expect that to become an issue for me soon since the battery I have is 7 years old, probably about 2 years longer than it was supposed to last but who's counting ?

the car cranks at normal speed. I returned the ignition parts after I determined they weren't the problem, so I didn't have to worry about the $200. Scan tool is reading that the crankshaft position sensor is "OK" although the car isn't running so i can't see how it would know that. I took the ignition piece out and cranked the car but could see no sparks in the boots.

No battery or starter issues... it cranks like a champ but the engine just won't start. I can hear the engine turn, just not start.


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98 Z24 5-speed

The crankshaft position sensor makes a pulsed signal from a reluctor wheel on the crankshaft, so when the engine is turning over it is sending a pulse to the ECM, that is how the ECM can read the Crank Sensor with the car not running. The ECM uses this signal to generate the ignition timing, so if it doesn't see a signal it won't send an output to the ICM to fire the plugs. Is the scantool showing it is OK because you aren't getting a code for it, or is it showing OK because you are seeing a signal for it on your scan tool ? Two different things.

I'm not following to well how you saw no spark thru the boots. I would think you could pull the coil pack off and take out the plugs and push them back into the boots and ground the electrode on the valve cover to see if you were getting spark to the plugs, but you'd have to make sure the plugs were against the spring inside the boots, I think the coil pack puts pressure on them to make a good connection.

You should be getting spark if you checked the fuses and changed everything you said because the ignition works by the pulse from the crankshaft going to the ECM which sends the signal to the ICM which puts voltage to the coils that fire the plugs, it's pretty simple and if all the parts are good and you aren't getting spark then it would have to be in the wiring. The only other reason would be if the theft lock is on, which I know nothing about but have seen procedures on resetting it in the forum if that light is on. I think those are your options if you have no spark, there may be different ones I'm not thinking about maybe someone else can bring up.

In my manual the list of engine not starting problems are

Fuel pressure, fuel pump, fpr, leaky injectors
Battery
incorrectly gapped plugs (yours should be alright)
broken wiring
bad ignition components(you changed out)
Crankshaft sensor(you say is good)
Broken timing chain(you say the engine cranks at normal speed, so shouldn't be the problem)

Those are the no start causes so take your pick. Just for kicks you could spray some starter fluid in the throttle body and see if the engine tries to start to rule out the fuel system and also would prove you have spark if it tries to start. If you check the plugs they should be wet if you aren't getting any spark. If your battery is good you are down to broken wiring being the problem. I think I'm about out of ideas without being there to look at it.

the scantool I was using was a rental from autozone, and i couldn't seem to find where the readings were for the crank sensor. it read ok on the screen, but i could not verify it with any numbers or signal voltage or anything... I am going to start there. Can't be too expensive to drop a new sensor in there and see.

If it's not that, I'm going to assume is a wiring/computer problem, and that goes beyond my areas of "expertise" (meaning things i'm even remotely comfortable working on). I'm pretty sure it's not theft lock as well, as the theft light is not doing anything to indicate it.

Thanks for all the suggestions.




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98 Z24 5-speed

You need 3 things to have a running engine. Fuel, spark, and compression. I would start by checking all 3. If one is out, still check the other 2.

Have you tested fuel pressure at the rail yet? My 03 Cavalier did the same thing. I took off the rail cap turned the ignition to run and then depressed the valve and no fuel. Fuel pump was dead.

xstatic180 wrote:the scantool I was using was a rental from autozone, and i couldn't seem to find where the readings were for the crank sensor. it read ok on the screen, but i could not verify it with any numbers or signal voltage or anything... I am going to start there. Can't be too expensive to drop a new sensor in there and see.

If it's not that, I'm going to assume is a wiring/computer problem, and that goes beyond my areas of "expertise" (meaning things i'm even remotely comfortable working on). I'm pretty sure it's not theft lock as well, as the theft light is not doing anything to indicate it.

Thanks for all the suggestions.

Was you losing any top end power before it stopped running ? You cat could have become plugged and that cause it not to run, but usually it will try to start or run for 30 - 60 seconds. Has your check engine light been on for awhile ? If you've been running rich it would cause it to plug the cat. I doubt that your ECM is bad since you are communicating with it thru the scan tool. Wiring problem is possible but I don't think that is it. Did you try starter fluid ? The most likely cause seems to be the CPS, but I wouldn't change it just for kicks, plus I think it is a PIA to change. Still think you are going to need to get a fuel pressure gauge to make sure it is the right pressure and the spark plug tool to see if you are getting spark. Then if that shows good you are going to need to do a compression check, then if that is good, sounds like it is your timing off.

accually the cps is easy ti change i had to on mine after i had my swap all done n my new harness was dirr from the one the motor came with ( harness didnt have abs i did). so i changed mine out wasnt bad few mins.

I know you checked this already, but, this sounds exactly like you lost your CKP signal, or Cam sensor signal. Both will result is the engine shutting off and not restarting.
You should check to see if you actually have a pulse coming from the ckp sensor. back probe it with a meter and have someone crank the engine while you watch for the voltage spikes. Or, use a test light. It can sometimes hard to see the voltage on a cheap meter.
Do the same for the cam sensor.