2001 SL1 misfire trouble

I'm looking for a little help here please:

We went away on vacation and ur 2001 SL1 sat for about 10 days. I tried to
start it when we got back and it ran very badly to say the least. It was
misfiring, had a strange odor from exhaust, and had no power. I let it run
for a few minutes and gave up. I came back later and started it up, and it
gradually ran smooth again so I took it for a spin, and figured I'd get to
it later if it happened again.

The very next day my wife went to use it and it was running bad again, just
like before. It has not cleared up since, and here is what I have
discovered/done:
- it has fault codes P0300 (random misfire) and P0340 Camshaft position
sensor.

I know it doesn't have a CPS, so I replaced the spark plugs and wires (they
were due anyway), and took measurements on each of the wires and coils. The
coils and wires measure normal.

Someone mentioned it could be a clogged catalytic converter, so I
disconnected the O2 sensor on the manifold and it had no affect at all on
the engine power/misfiring. There is also a large amount of flow from the
tailpipe (enough to blow the rocks in my driveway out of the way from it).

Anyone have any ideas on what could be causing this? What are my options
here?

Thanks in advance for any and all help!

Justin

 

When I recently had the same problem, it was Cyl. 3. Oil fouled plug. BUT
you changed the plugs and wires, right? PCV sensor / valve or whatever it
is called... Could that cause this problem?

Clogged fuel injector?

Joe in Northern, NJ - V#8013-R

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A couple of thoughts for consideration:

Look carefully at the ignition coil/plug wire tower. They have a tendency
to corrode over time and can cause misfiring. Removing and cleaning is
fairly simple and good preventive maintenance.

Make sure you gapped the plugs correctly. I'm not sure of your year, our
'96 lists .060" in the manual, but is supposed to be .040".

Make sure the plug wires are run identically (and cross themselves in the
same place and manner) to the way they were from the factory/previously.

Make sure your battery is putting out the desired voltage and definitely
over 12V since the computer can do strange things with a bad cell causing a
low voltage situation.

The connectors to one of the fuel injectors could be dirty/oxidized or not
making good connection. These can be easily unplugged and sprayed with a
good electrical contact cleaner/lubricant available from radio shack or
similar electrical store.

The Crank Position Sensor could be bad causing the OBDII code you are
seeing.

Saturn's are notorious for having the Coolant Temperature Sensor fail and
not setting that code. Typically this could cause the engine to run badly
upon start up. These are cheap and fairly easily replaced.

You could have gotten some bad gas last fill up. Try adding a good fuel
injector cleaner (I use Dupont Techron) and running the tank down as far as
possible before refueling.

Good luck.

Bob

 

ECT sensor could behave like this. If it gives a "cold" value when you
start it up it will run far to rich. What "brand" and type of plugs did
you buy? Sometimes a .040 gap works better on the s-series.

Below 15k ohms is good.

Other than ECT sensor I would still focus on the plugs and wires and
also look at fuel pressure and I should go ahead and ask when you last
replaced your fuel filter.





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Well I have discovered that number 4 cylinder is not getting spark at all.
I don't know why but I do know that for a fact. I am going to check all
connections again and re-measure everything to make sure I didn't miss
something.

Any ideas oon what would block the signal to #4 cylinder?

 

Clean the corrosion from the ignition tower block...

 

Is the engine single overhead cam? SL1, SC1 use SOHC design - This
engine misfire
problem besides plug, wires and ignition coils - the intake manifold
gasket aslo leaking
You can check by spraying some carburetor clean at the intake manifold
cylinder #1, 2
area. If misfire that is the vehicle problem. Part for this is cheap
but labour take about
3-5 hrs with proper equipment an tools.
As for the rotten egg smell is from the catalytic converter. this
occurs when trying to burn
of excess fuel due to the misfire. If left unrepair will permanetly
damage the catalytic converter. I recommend fix the problem ASAP.

 

I have what sounds like the exact same problem except mine is cylinder #1.
If you find it let me know. I too have replaced my plugs and wires as well
as cleaned the contacts on the ignition tower. Mine is a 98 SL1. 169,000 km.

 

Hi, Justin,
Take a look at
http://www.magnecor.com/magnecor1/techbulletins/techsat.htm. You may need to
adjust the spark plug gap.