12thstreetjunkman

iTrader: (16)

I have hp tuners, but havn't used it much, my car is missing like crazy from anything above idle, at idle it runs fine, and I can unplug each injector and the engine changes pitch, so it isn't missing at idle. When you drive it, you can feel a definite vibration from a dead cylinder. What is the best method using hp tuners to help pinpoint the cylinder giving me trouble. It isn't throwing any codes when I chect the dtc's. I had put a post up on how to log misfires, I think I have figured it out, or at least I have got the current misfires for each cylinder loaded into the tables, but when I go out and drive it, They all show 0? I am lost, If anyone can help, please let me know.

jimmyblue

iTrader: (11)

log all 8 "Misfire Current" PIDs and go after the one that
stands out from the rest.

Very unlikely that misfires-current would show zeroes
consistently. There should be a little bit of chatter,
single digits or teens on a low mods car. "Misfire Current
Cylinder #1" through "Misfire Current Cylinder #8" are
what you want. If they all say zero, all the time, something
isn't right or your tune is too perfect.

I don't know whether there are things you could do to
the tune data, code suppression etc., that might suppress
misfire counting; I've always just left it be and took what
it told me. I have used these PIDs to find a loose plug
wire.

12thstreetjunkman

iTrader: (16)

I was kind of wondering about my pcm having something turned off on it preventing from showing misfire codes, I assumed it was all stock when I got the pcm, and all I have done is turn off vatts, egr stuff, air stuff, but everything else should still be on there. I will try again, to log it, I didn't understand why it was showing all 0's. I thought maybe there was something else I needed to do. The other values left on the table, temp/rpm/etc were all showing correct.

RedHardSupra

iTrader: (1)

there's also a bunch of other misfire PIDs, cylinder mode index, revolution mode index, total, etc.
what do they all represent? how do i use them generically to spot what kinds of problems? Right now i'm mostly interested in checking if injectors are working properly, as I put in a set bought on forums, and would like to know if they work well.
how would it show up if you did have a loose spark plug wire?

WS6FirebirdTA00

iTrader: (33)

last timei was logging these things i saw a misfire of 0 all the way across...so yo say they should be going to low numbers? ill try and relog today and see what it says, maybe it wasnt connected

RedHardSupra

iTrader: (1)

i get some single digit misfires on few cylinders, is that ok? i have new plugs/wires/injectors so it should be ok, but i'd rather scan and know for sure.

02sierraz71_5.3

iTrader: (2)

If they all say zero, all the time, something
isn't right or your tune is too perfect.
what do you mean? desnstized the misfire tables too much?

WS6FirebirdTA00

iTrader: (33)

yeah cause im seeing 0 all the time from what i can tell id like to know thsi as well

12thstreetjunkman

iTrader: (16)

up again, I just swapped out coils with another motor, put new plugs in, all the plug wires are clicking once, and twice at the coil. Still this damn miss and no code or misfire on the table, whole freakin car shakes. What is the stock misfire #'s maybe It has been messed with before me.

WS6FirebirdTA00

iTrader: (33)

mine have never been messed with and it was missing cause i didnt have my wires plugged in all the way one time. check your pushrods, maybe u have one broken, happened to my friend, first his maf was bad, it would idle great and then down the road it would miss like a son of a bitch, then he broke a pushrod after we fixed that, u could hear it missing slightly at idle, those are 2 easy things to check out. what are your fuel trims? if they are maxed out thats a sign of a bad maf. check the trims and the MAF rate and let me know what they both say.

i would still like to know about this misfire deal, mine stays at 0 and i would imagine iwth the cam i would see something