1992 SL2: spark, fuel, air, no fire (new air & fuel filter, spark plugs, wires)

[onixwj]

1992 Saturn SL2 DOHC 275,000 miles

Car stalled while driving at about 10mph. Wouldn't start. Turned over, but no firing. Fuel gauge low, so assumed out of fuel. 12 hours later, added fuel, started without hesitation. Re-fueled and realized it had *not* been empty. After a couple miles of driving, stalled again. Towed home.

After sitting a week, started without hesitation. Didn't drive it. Fuel filter had about 75,000 miles on it, so replaced that. Replaced dirty air filter. Fired once while cranking, but didn't start. No more firing.

Observed spark between coil towers 1 & 2 (didn't look at others). One terminal corroded. Valve cover gasket is leaky, so three plugs were oily (about 2" of oil in wells). Plugs covered in carbon deposits. Replaced plugs and wires. No firing. Pressed fuel test valve and got a spray.

What next?

[redkees@msn.com]

Clean the corosion off the coil tower tips gently with steel wool until shiny, apply dialectic grease on the tips and re-install spark plug boots.
Take plugs out of engine clean off oil regap at .040 and reinstall. Replace ECTS-engine coolant temp sensor, probably cracked if it the original; replace with new steel tipped replacement and also replace the wire connector too.
Start the car and see if it runs. Then plan on replacing cam cover gasket to stop leaking oil on the plugs.

[onixwj]

Thanks for the suggestions, Redkees. Responses follow inline:

Originally Posted by redkees@msn.com

Clean the corosion off the coil tower tips gently with steel wool until shiny

I did that when installing the new wires.

Originally Posted by redkees@msn.com

apply dialectic grease on the tips and re-install spark plug boots.

The new ones came with grease applied.

Originally Posted by redkees@msn.com

Take plugs out of engine clean off oil regap at .040 and reinstall.

I believe they were pre-gapped at .04, though in a rush and in the rain, I didn't dig up my gap gauge and verify. In the past, I always have, and have always found them to be gapped properly already. I'll double-check.

Originally Posted by redkees@msn.com

Replace ECTS-engine coolant temp sensor, probably cracked if it the original; replace with new steel tipped replacement and also replace the wire connector too.

It was replaced about 75,000 miles ago. I don't know if the mechanic used the newer, preferable, design, or one that was the same as the original. I'll check it for cracking.

Would a faulty ECTS prevent the engine from firing when the starter is cranking?

Originally Posted by redkees@msn.com

plan on replacing cam cover gasket to stop leaking oil on the plugs.

That's been in the plans for quite some time, though it seems that I need to bump up the priority now.

[OldNuc]

If the engine starts and runs and then stalls when its warmed up do the following. Right after it stalls remove the #1 and #4 plug wire from the coil and crank the engine, if no spark jumps between the 1-4 towers then the CKS, Crank Position Sensor, has failed. Replace it. It is a 14.00 part at the parts store and is conveniently located behind the starter on the back of the block. There is a richpin video on how to replace it.

[onixwj]

Originally Posted by OldNuc

If the engine starts and runs and then stalls when its warmed up do the following. Right after it stalls remove the #1 and #4 plug wire from the coil and crank the engine, if no spark jumps between the 1-4 towers then the CKS, Crank Position Sensor, has failed. Replace it. It is a 14.00 part at the parts store and is conveniently located behind the starter on the back of the block. There is a richpin video on how to replace it.

Thanks. If I can get it to start and it stalls again after warming up, I'll be sure to check this.

For now, it won't start, and it's cold.

[OldNuc]

Then run the spark test. They will eventually die where there is never any spark.

[onixwj]

Now, after sitting for about a day and a half, it started immediately when I tried.

[OldNuc]

That still could be a failing CKS (crankshaft position sensor). If it dies again promptly do the spark test.

Nothing ever fixes itself.

[onixwj]

Originally Posted by onixwj

Now, after sitting for about a day and a half, it started immediately when I tried.

I didn't drive it yesterday after starting it. It sat for about 24 hours, and started immediately when I tried this morning. I stopped it, started again without trouble, and let it idle for an hour. No problem. Stopped it, started again, drove it around the block a few times, then stopped it.

Then it sat for about an hour, and when I tried to start it, it wouldn't fire. I then removed the leftmost spark plug wires (for cylinders 1 and 4) from the coil tower, cranked the engine, and found that a spark was jumping between the two terminals.

I'm stumped.

[OldNuc]

Put the wires back on and see if it will start. When it dies what dash lights come on? Oil pressure for sure but what else if anything.

[onixwj]

Originally Posted by OldNuc

Put the wires back on and see if it will start.

I did that. It didn't start.

Originally Posted by OldNuc

When it dies what dash lights come on? Oil pressure for sure but what else if anything.

I'll check this evening and report back.

[OldNuc]

The trick is going to be to figure out what is shutting it down.

[onixwj]

After sitting a few days, it started right up without hesitation.

Hoping to read any codes that the computer might be showing, I checked the instrument cluster bulbs, found two burned out, and swapped them to the airbag and anti-lock brakes spots, since this care doesn't have either feature.

With known-good bulbs (known by swapping them to another position and observing them lighting) the service engine, overheat, and up-shift lights do not light when turning the key to the on position. Do these three have anything in common?