midweekwarrior

Hey, I just pulled Code 13 from my car. Suggestions how to fix it?

Symptoms:

Car shut completely off, then would not crank for about 15mins. During that time the starter engages but no engine turn over.

History:

The opti spark was replaced last year, and two weeks ago the water pump was replaced.


Please don't tell me it's an opti again *facepalm and maybe a nice conversation with my mechanic...

Cliff Harris

Code 13 is low O2 sensor voltage. Could be bad O2 sensor or wiring shorted to ground.

Engine not cranking is either low battery, bad battery cable connections, bad starter or the contacts in the starter solenoid are burned.

midweekwarrior

would that battery issues cause the car to shut off while driving though?

SunCr

If the alternator was bad yes. A battery is good for maybe an hour. After that, the voltage will be too low to keep it going. Sounds like your Vette has more than one thing going on.

midweekwarrior

alright. let's tackle the O2 sensor problem..

the alternator is rather straight forward (replaced those before).

What, how and where is the O2 sensor? and how do you replace it?
Are there other things the sensor controls ?

Cliff Harris

The O2 sensor(s) are in the exhaust pipe. The early cars have only one in the driver's side exhaust pipe, just under the junction with the exhaust manifold. It's on the back of the pipe and angled toward the block.

Newer cars have 4 O2 sensors, one in front of and one behind each front catalytic converter.

Here's our guy. There are special O2 sensor sockets, but I just unplug the connector and slip a box end wrench over the wire. I'm sure it's a metric size, but 7/8" works for me. Make REALLY SURE the replacement has anti-seize on it (the Bosch O2 sensor I just put in had the anti-seize on it already) or you'll never get it out again... I have a new Magnaflow Y pipe and the mounting flanges are upside down compared to the stock ones.

John Robinson

On my 93 LT1 I only have two O2 sensors. I replaced the the right side sensor by soaking it in penetrating fluid. Then using a long extension and a little imagination I was able to come down from the top of the engine bay and and put a socket on the sensor and used my impact driver on a low setting to brake the sensor loose. Of course that meant I had to cut the wire to get the socket on the sensor. After I removed the old sensor then I was able to get under the car and put the new sensor in and snug it down. You really don't have to torgue it too tight since the sealant and temperature will seal it.

midweekwarrior

Okay, found some time to mess with it. I've managed to find the O2 sensor - will order a new one and some tools.

Next, I decided to check what y'all said about the alternator...

So i cranked it up and let it run to see if it would shut off; and it did about 35 minutes later, and gave the same symptoms and cranked back up 15mins or so afterwards. The console displayed the service engine light and a battery light. No codes this time. Verdict? Alternator?

midweekwarrior

Okay, im going to bite now.. the alternator was not it.. there is 14.1 coming from it.

The starter engages but there is no spark - and this is sporadic, sometimes it starts and others it doesn't and it cuts out on me while im driving. The water pump has been messed with so could it be the opti (again)? But, if it is the opti how can i check it since i am not getting any codes for it.

Cliff Harris

Check the ignition module to make sure there is thermal grease under it (and the screws are tight). They can fail if they get hot.

John Robinson

I totally agree with this advice and would add that as long as you are there also check the coil heat sink grease.

I just went through having bad signals and the tachometer needle jumping around with a rough running engine. Pulled the coil and cleaned the surfaces with brake cleaner then liberally coated the surface to the engine block with dielectric grease. My car is now running smooth and no more jumping needle on the tach.

chrldo

does your battery go low and need re-charged between attempts to start car? or do you let it cool down and it will restart?

midweekwarrior

It starts after the car cools down (I believe)

chrldo

if it starts after it cools down, i would look at the starter. pull it out and take it to a shop the rebuilds starters and alternators. it can short out and pull the amps down low enough to cause the electrical components to stop working.

coupeguy2001

If your car shuts off, I would look at the ignition coil in the distributor, or the module.
That being said, it is possible you have a bad ignition switch.
When the car shuts off, check the pink wire on the dist. cap for power.
If you mean "turn over" to mean start, turn over usually means the starter is turning the crankshaft.

chrldo

did you resolve the code 13? this discussion is about a 92 vette right?

midweekwarrior

I have not fixed the code 13 as of yet, the priority is getting the car drive-able. Being a phd student doing research and not having a car is kind of a huge problem. Walking almost 2 hours to lab everyday is getting old very quickly.

From what I can tell there is power to the Opti or at least the wire that runs from the ICM to the driver's side of the opti and connects at the top, and the battery appears to hover around 13.6, and the alternator is good (14.1).

The ICM, ignition coil, pigtail and the other wire to the opti are used ones i installed from a camaro LT1 this time last year when i replaced the Opti Spark.

Coupeguy2001, the car starts and runs well for a bit then shuts completely off and will not start again. The starter engages but there is no spark. However, usually after i let it sit for several hours it will start up again without any hesitation. It seems to be connected with the car heating up, usually 15-20min or so after reaching operating temp. Also, before i was able to initially jump start the car and have it run even when it was hot, now i can't even do that.
Other things:
The car was overheating, and the water pump has been removed 2x during the replacement. Once to replace it and a second time because I damaged the coupling.
The opti spark was replaced this time last year
The car is running rich (when it does run)

chrldo

its frustrating, i know! we've got to ask questions its the only way we can help. when you say starter engages ,do you mean the bendix kicks out the gear and you hear a loud CLICK or do you mean the engine cranks over and over and wont start. if you mean the starter clicks but doesnt crank after the car is warm then suspect the starter. if the engine is cranking over but wont start after its warm then its electrical. like a solder joint on a pc board that is expanding and contracting with the temp. do you have the old coil?

kimmer

From what you have said, If your engine turns over, starts when cold or cooled down you most likely have a bad icm or coil. Can you verify spark from the coil when it doesn't start. I just went through this after replacing my opti, ended up being junk new icm and coil from a chainstore. Put in gm parts and my problem was solved. But I also had a bad coil plug harness. I know this sounds weird but it seems that a lot of members have coil & icm problems after changing the opti like it takes them out with a power surge.

midweekwarrior

i hear a "whirring" type noise when i try to start the car, not the "Clicking" noise you'd usually associate with the starter being bad.

How can i check for spark from the coil and what voltage will i be looking for? Pictures if you can as well


Can you check for voltage to/from the ICM as well? if so how.

Im fairly handy with a MM