I have a 1999 SL1 with ~154000 miles on it. It has been
running great and I have had no issues with the car
until early this week. I went to start it Tuesday
morning (it was colder and rained Monday night). It
would not start. I stay home from work and went through
the usual. Made sure the fuel pump was working. I
replaced plugs and wires because they were pretty bad.
I changed the oil because it was due and I was working
on the car anyway. After all of this, it started in the
afternoon. By this time the weather had cleared up and
it was sunny. I thought that the plugs and wires must
have fixed it. It was rainy again on Wednesday and when
I tried to start it, it refused. It will turn over but
just won''t fire. Anybody have any ideas?

Well, the first place I would look would be at the computer, to see if there were any codes stored in the system.


Next thing I would do, is check for proper spark and also proper fuel - of course, this can only be done when the vehicle is in ''failure mode'' early in the morning, under cool and wet conditions ... not fun

Thank you for your response OceanArcher. I know that I
have fuel pressure at the injector rail. What is the
best way to check for spark? Error codes 420 and 404
are present. I don’t think these are the issue, as I
have had these before and been able to ignore them.
Also they are both exhaust related. I am confident that
the 420 is caused by a bad sensor. I am unsure of the
cause of the 404. Any help is greatly appreciated.

OK ... the 420 error refers to the catalytic converter system. Hopefully just a bad sensor.


The 404 error refers to the EGR system, and suggests that the EGR valve is stuck in the open position.


As for checking for spark, an easy way would be to take a neon lamp type sensor, and hold near each of the plug wireswhile an assistant cranks the engine. You should get indication of spark by flash of the neon lamp.

I spent the afternoon working on the car. It was a nice
day today, and the car still wouldn''t start. So I am
going back on my original thought that it was weather
related. I do not have spark on any of the plugs. I
checked the secondary resistance on both coil packs and
they were correct. The ignition module has ground and
power. Any ideas on where to go from here?

Here are a couple of things:


Faulty or incorrectly gapped spark plugs.Plugs do not come already gapped, and must be set at .040 for your vehicle.


Broken, loose or disconnected wires at the ignition coil - or faulty coil.


Ignition components damaged or disconnected.


Crankshaft Postion Sensor defective.


Hope you find the problem ...

+ 1 on CPS if it goes bad, no spark. Period. These often flake out shortly before death.

Today:
<ul>[*]I replaced the Crankshaft Position Sensor (I found the old one when probed had infinite resistance between the pins). [*]I cleaned the throttle body (it was really gummed up). [*]I used a wire brush to remove all of the junk from the EGR Valve.[/list]The car starts and runs like a charm. It looks like the CPS was the cause of the no spark condition.

There is still a small issue though. I now have a service light with a little wrench next to it. The light comes on about a minute after the car starts up and it stays on. I tried disconnecting the battery to reset the light, and that worked. But one minute after the car starts, the light comes back on. The Saturn manual says this could be caused by a serious condition, but my OBD-II code reader doesn''t give me any codes. Is the car safe to drive? Where should I go from here? I was hoping someone on this forum might have an idea.

Thank you for all of your help so far.

One final update just for anyone who has this issue in
the future.

I brought the car to my mechanic because of that light.
He got out his fancy diagnostic computer and found that
the light was related to the sensor I had just replaced.
It turns out that one of the easiest ways to reset this
particular error light was to go through enough ignition
cycles once the issue was resolved. We started the car
a few more times and the light is now gone. Luckily he
was nice enough to send me on my way without a bill.
Anyway, the CPS was really the only problem, and the car
runs great again.

Thank you again for all of your help.