Dirteeboy808

iTrader: (11)

Is the ECU grounded through the harness or is grounded with it's casing or something like that<sorry noob question>

I'm throwing CEL codes "misfiring cyl 2 and 3" codes are on this post if you feel like reading it

http://forums.nasioc.com/forums/show....php?t=1281260

any suggestions and where the ECU is grounded???

Thanks

BTW 04 STI

91sleeper

iTrader: (13)

why would the ground on the ecu effect cyl missfire codes? check your plugs and there is a simple test you can do to check if it's a bad coilpack or plug wire. is your cars idle rough? bring it out tomorrow night and we'll have a look

iNfEk

iTrader: (33)

grounding is through both the case and the wireharness

iNfEk

iTrader: (33)

the guy that posted after your question is correct. the cylinders are as follows if your looking at the front of the car

3 4
1 2

misfiring are usually due to the spark plugs as notated earlier but there would be no definitive way to find out if your utec was bad unless you send it back to TXS for analasys. i would probably contact TXS on this one if you have your utec connected to the car. Have you tested it without the utec connected to the car for a while? This is very similar to other types of troubleshooting that you eliminate all other things that would cause your problem.

since the CEL says misfire... firing comes from your spark plugs so that would be the first step. you'll definitely need to research this on your own since no two cars are a like.

good luck though

iNfEk

iTrader: (33)

also DEFINITELY make sure you DISCONNECTED the green connectors on the drivers side under the dash.

Dirteeboy808

iTrader: (11)

I figure I start with what I took off or messed with first to start off, which was the ECU and because the car acts the same with and without the UTEC, maybe the ECU not grounding good so maybe it might be throwing some of the electricals off....before checking plugs which is a PITA to get to.....the meet is a little far as the car runs really bad, idle is terrible...backfires, almost dies off, running really rich2.....car tends to die want to die prior to boost, so driving is kind of sketch

how do check the coilpacks and wires??was going to switch them, but since the (2) seperate misfires are on seperate coilpacks wouldn't tests be kind of in???

if someone like to stop by to drop by and diagnose problem, I'd be more than happy to buy lunch, drinks and even gas money.....btw live in Waikele

thanks for the help

Dirteeboy808

iTrader: (11)

I don't understand how it would start misfiring especially at those random cylinders as I only upgraded the software of the UTEC, without any maps installed....and set at '0' or stock setting......I tried resetting ECU, but still runs like doodoo

oh yeah the test plugs are unplugged....

iNfEk

iTrader: (33)

the car wanting to die before boost could be a sign. did you remove your intercooler? you might want to double check that all the hose clamps are tight for any connections. you suppositely only changed the firmware version on the UTEC. the UTEC is technically only a piggy back since it goes onto your ECU and doesn't replace it. if it runs the same with an without the UTEC the the trouble has to be on your engine somewhere or a ground wire got cut or disconnected somewhere. I know that grounding is very important since without a ground sensors don't run right. did you touch anything in the engine even though it could be considered small and technically not related to your trouble? yes the plugs are a PITA but hey you have to pay to play. if the plugs are fouled that could cause your trouble. Have you reset the computer after you took the UTEC off the car?

waikele... the meet at aiea so that's kinda far.

Jon

Dirteeboy808

iTrader: (11)

the only thing that was touched during the UTEC install was the ECU or course and the battery needed to be changed since it went dead when I was doing the install.....I checked the ground cable to the battery to see if anything was loose, but was ok...........=(

nothing else was touched...

yeah I resetted the ECU: unplugged negative terminal, pumped brakes and left door open......I'll double check the grounds and see if that helps if not, going to the next task of the plugs..

thanks, Mike

91sleeper

iTrader: (13)

ok here is what you have to do. if your looking at the coilpack you start the car and then go from 1 to 2 to 3 to 4. you listen to the car and how it's idleling. you remove the plugwire at the coilpack just a little and look for a spark. then remove it all the way and see if the motor sounds worse or stays the same. if the car sounds worse then plug the wire back and that plug, wire, and coil are fine and you go on the the next one. if you don't see a spark then the coil is bad. if you see a spark but the motor doesn't sound any different then bad plug or wire. i can come help you tomorrow but it will have to be later at like 7pm. lmk and i'll shoot out there after work. try and see if anyone has a spare ecu you can borrow to plug in and see if the ecu is als the problem.

iNfEk

iTrader: (33)

That would be right if you were dealing with spark plug wires like on a GC8 but these are coil packs not spark plug wires. the contact is all the way in closest to the coil. you will not be able to see the spark.

as soon as you remove the screw holding the coilpack in that would disturb the firing order of the spark plugs even more.

Since these are coilpacks they have wires connected to them on each side. The white connectors stay in front and the black ones stay to the back. someone on another board came up with a saying that is quite racist so I won't post it up but you get the point. make sure those connectors are on securely and the should snap in. if in doubt remove and reconnect. I have seen CEL's thrown on another suby's car for this connector coming undone.

Jon

Dirteeboy808

iTrader: (11)

that'd be cool if you want to stop by tomorrow...I live in a townhouse area and it's a little dark, so we may have to find a lighted area and that the resident manager is a little strict so he might not let us run the car since the car idles loud and backfires pretty loud...i'll PM you my number, LMK if you want dinner, I have drinks alcoholic and non...a

91sleeper

iTrader: (13)

hey i tried calling you but i guess your passed out already. try putting up a list of all your mods since this doesn't seem like a bad plug or coilpack.

iNfEk

iTrader: (33)

the guy that replied to you on your original thread hit the nail on the head when he stated that you should be at 1.0-1.2 volts at idle.

If you look at the numbers you posted you stated that your WOT or full throttle is set to 5.5. why is your idle anywhere near that?

Further since this is probably user error in tuning this should NOT affect your ECU in anyway shape or form since it is only a piggy back computer and NOT a reflash or standalone.

you stated earlier in post 6 of this thread that the car runs the same with and without the UTEC connected. that baffles me because of the earlier statement I made on this post.

When resetting your ECU you should have the UTEC completely disconnected from the car and not even wired in at all. Connect all the connector securely onto the ECU and that your battery negative terminal (at least) is disconnected prior to touching anything with your ECU. when everything is reconnected as far as ECU is concerned hold the brake peddle down for a few seconds until your mileage display disappears. Then reconnect the battery and start your car. The idle SHOULD be different. IF not then you need to further investigate your engine situation. Your engines ECU should retain all factory parameters since your ECU has NOT been flashed at all. IF your car still idles like **** then you might have fried your ECU.

if all things as far as your coilpacks and ground wires...etc. in the engine bay are fine you should have no problems. I would double check the connectors connecting to the coilpacks as i mentioned earlier and see if that makes a difference.

good luck dude.

at what point (RPM) with the UTEC disconnected from your car and you driving it does the car feel like its going to die?

Jon

91sleeper

iTrader: (13)

just a though but have you also stuck a voltmeter on the battery and alternator since you did change out the battery. i mean i dought the battery is bad but could it maybe be the alternator? if you don't have one i'll bring mine with me and we can check that too.