Fickert

iTrader: (6)

I am having issues my 8, recently just happened after I drove it from sitting for 3-4 weeks, I forget. Anyway, got in the car and I notice a very minor jolt while giving it a pull in sixth gear to jump up to 70. So I duplicated this and it did it again. I also saw the cel start flashing (I have a full exhaust minus header so I am used to the cel for the rear o2) but it has never flashed before, signaling a misfire. So I went and got it checked at autozone. I have a custom ls1 kit with msd wires and new plugs that never gave me trouble a few months before letting it sit for this period. I got it checked, and found the low voltage error, the front heater core, and two signals of misfires in the rear rotor. I did a 20 pump brake for the eccentric shaft sensor to reset it. Still nothing and now I am not sure where to go from here. I replaced the front o2 about 4 months ago and so this is why I am confused. Any help will be great! And I will get codes up later, I will haveto get it tested again for exact codes.

My thoughts,

Obviously, to me at least, the low voltage is giving my coils not enough juice to fire properly, causing the unusual misfire and thus the front o2 is registering the misfire against the reading it is expecting of no misfire. But I am not sure. I don't have a volt meter at the moment to test the alt to see if it is going bad at all. Also, It cannot be a bad ground. I have a grounding kit installed as well.

Thanks in advance!

Legot

iTrader: (1)

Cheap meters literally cost $1 at stores like harbor freight or online. Get one, they're useful. What makes you think you have low voltage? It's not like you can "feel" the voltage your battery is at. Low voltage won't do much to stop a coil until it is very low, for most the threshold for non-riring behavior is below 9v, and at that point it is highly unlikely that your car would be starting. Misfires aren't detected by the O2 sensors, they are sensed by erratic variations in the engine speed, picked up by the ESS. You shouldn't reset the KAM without resetting the NVRAM. It causes some issues, either reset them both or don't reset them at all.

Is your ESS clean? What kind of coils are you using?

Is it possible your ignition just failed? That's a thing that happens sometimes.

RXeligion

Seems like it could be a bad ground. Go over everything you changed and ensure the grounds are on good and tight. A digital multi meter is not that expensive or hard to find. I bought mine at Lowes.

Fickert

iTrader: (6)

I had the car checked at auto zone and one if the codes read low voltage. But I am not sure why. I will have to check it when I get back. And if it was a bad coil it would have shown up on the code reader right? I also have d585 ls1coils. I will look over my grounds when I get back home here and see if I find anything.

Fickert

iTrader: (6)

Just got the codes read again to get the actual codes. The big one I am seeing is a p0562. Then a p0302. And the usual p0037. So no front o2 sensor error my mistake.

rioredstang

P0562 is keep alive memory for ecu. P0037 is o2 heater circuit low voltage. The ecm looks at the o2 heater circuit at koeo(key on engine off). It should be about 9-10 volts.
Keep alive memory could have a bad room fuse or loose connection.

Fickert

iTrader: (6)

Right, I am not sure, a simple room fuse can cause this? Idk if it is a loose connection as I just started it up and drove it from storage. But I am up in Akron now, and I cannot check fuses or for any loose connections any more. Anything else I should possibly look for when I get back home for thanksgiving?

rioredstang

P0562 is the memory for the computer. It will not effect the running of the engine. P0302 for misfire is what you need to check. Needs a compression check by a qualified shop.

Legot

iTrader: (1)

Can I have a source for that? All I can find are low voltage references.

RIWWP

iTrader: (2)

From the service manual:

Fickert

iTrader: (6)

So I have checked grounds, terminals, plugs etc and found nothing, what exactly is an open circuit to the pcm? Like no fuse it it's place or what? I am not sure.

Legot

iTrader: (1)

It's in the last post....

Open circuit means disconnected. 5J should be connected to the positive terminal and show the exact same voltage as the battery.