If you get a code34 anyway..any harm in unplugging sub harness

[s13pignose]

I don't know the ends and out of knock sensor..electrically that is. But say I'm getting code 34 constantly..even if it goes away with luck after driving for a while then resetting ecu. Would it be better for me to just go a head and un plug the sub harness running of the sensor from the ecu harness. Cause I'm thinking I'm gonna get the code no matter what till the problem fix, and my car has these random fits where the tach bounces back and forth and car may even die...leading me to think there's a ground issue involving the knock sensor. But I'm thinking if I unplug it wouldn't it eliminate all of that if knock sensor is the problem. Right now I just need something to prevent the jerking and tach bouncing..cause its embarrassing and extremely annoying. I can deal with the poor mpg and loss of power from having the code.

Just wanted opinions. Like I said I'm probably gonna have the code harness plugged in or not

[s13pignose]

BTW I'm N/A with basic bolt-ons and never adjusted my timing advance. Been running 93 octane since the code 34 knock sensor and nothing else. So if unplugging the harness off the sensor will help..I'm thinking I should be okay? I've ran with it unplugged. once before on accident no problems

[240s4life]

don't know if it will do it when you unplug the knock sensor but the car may go into a limp mode like it does when you unplug the maf.

[s13pignose]

Well from what I've read thats what it should be in know..like it's suppose to retard timing..definitely didn't advance it lol. Cause as long as I have that 34 car has no pep. Which is my reason for posting..I really have nothing to loose..I'm just wondering if it will cure the tach jumping, car cutting off, and relay clicking. I know I will always have that code until I get things figured out, and definitely with the harness unplugged. I wonder if all that happens because whatever the problem is goes and comes, and the car responds accordingly. Sorta like a loose ground if you were to hit a bump..every time u hit the car responds?

[s13pignose]

?? Bump for more input if any out there..thanks

[Jonnie Fraz]

If I remember correctly the ECU will dump more fuel to keep from knocking. It is not that it is detonating it is just the ECU does not know if it is so dump fuel.

[s13pignose]

Alright..well I tried driving with it unplug..didn't even make it around the block before it started messing up. So just cleaned my iacv again, plugs, and maf. I checked my ground cable..I might need to ground it somewhere else. Right now I got the end grounded on this part on the lower half of the intake manifold. I couldn't move the cable any with my hand so thought it was on tight..but went at it with my wrench and got couple more turns out of it. I dunno how loose a cable has to be to make the car act weird.

Anyway I plug the subharness back in, and after all the stuff mentioned above I'm gonna reset the ecu and see what happens.

Thanks

Also whenever I clean the IACV down the hose running off from it to my intake..when I pull my plugs they look white on the side electrode..instead just looking metal..kinda off white and the color fades. I did put the plugs in there prolly last month..maybe they turn that way with age? Cause last time I cleaned the IACV I had about month old plugs, and after cleaning the IACV only one looked like that.

[s13pignose]

Tried driving with the maf unplugged same issues..with the sub harness unplugged same issue. I already replaced my CTS like 3 months ago laong with fuel filter..dis rotor and cap

[Om1kron]

why would you drive with the maf unplugged?

[japslapsilvia]

have u checked to see if the knock sensor is cracked??

[s13pignose]

Originally Posted by Om1kron

why would you drive with the maf unplugged?

I thought a way to check and see if your maf was bad or going bad was to unplug and see if it made a diff? By drive I really should've said back up a couple yards and then move back in my drive way.

No I haven't check the sensor. I would but I figure as much of a pain as it is to get it off might aswell have a new one on hand, but I hate to order one ahead of time and that not even be the problem. Thats the thing from what I've read so many things can cause a code 34.

I noticed sometimes the tach needle drops REALLY fast if I let off the gas quick..and also when the car goes into next gear (auto btw) or if I hit a bump..it sometimes will do the jerk..big bumps almost dies.

I mean I'm willing to spend the money to fix whatever it is..if I knew for sure what it was to fix. Also think the IACV is on it's way out the door. You can take the car and put it in park, and it'll stay a tad above 1k and then idle normal. I threw a code for that first time ever SAT night..went home and cleared it headed back out. Still almost dies when I start the car first thing in the morning.

[s13pignose]

Originally Posted by Om1kron

why would you drive with the maf unplugged?

BTW read your build thread some..props on being able to deal with all that wiring cause my car is about to drive me crazy with this. You have an SR and I have a ka, but in your experience do you think it could be my coil or fuel pump? Also could eccs relay cause all of this..cause when ever the tach needle jumps in response to the problem..that relay near the ecu clicks each time

[smelly240]

Code 34 cannot be thrown for the engine knocking.

Its for a malfunctioning sensor/bad wiring.

just thought you should know.

[s13pignose]

OKAY I FINALLY HAVE A BREAK THROUGH...SOMETHING to work with

Yeah I type in all caps..cause I'm excited I have pinpointed something definitely wrong.

Okay there's part of the wiring harness wrapped up in wire loom..bigger than the type used to wrap the wires near the front of the motor. It's past the last fuel injector closest to the fire wall. Prior to pinpointing this area, I went out side took the cover off my fuel pump to jiggle wires nothing.. jiggled sub harness to knock sensor...nothing. All I had to do was touch the part of the harness in the big loom mentioned above..and the car cut off INSTANTLY! It never fails..did it 3 times. The lighter u touch it..it almost dies but not quite. So I think this is why I hit a bump or anything that would cause it to move..I get that jerk. Had my dad to tap it while I watch the tach..sure enough the car almost dies..tach needle drops..and relay near ecu clicks.

I'm suppose to have a guy that's good at car electrical look at it thursday..but if it's left all on me, at least I got an area to work with. Don't know what's going on inside till I open..which I wouldn't want to anyway cause been off and on raining to day.

Try and find a pic under the hood off a ka s14..and circle the area in ms paint and post

[s13pignose]

Not my car..but best pic I could find

The circled area..I drew a red arrow to point at it in case circle was too small when I uploaded on imageshack. Except that par of the harness on my car is bent up like an up side down U

[Om1kron]

Originally Posted by smelly240

Code 34 cannot be thrown for the engine knocking.

Its for a malfunctioning sensor/bad wiring.

just thought you should know.

And most of the time the sensors(knock) will throw a code if not tq'ed down properly as well. Hence why i'm just going to throw an ohm resistor on mine and call it a day.

[smelly240]

You can always test if its a bad sensor or bad wiring with a 1 megaohm resistor - stick one end in each end of the knock sensors plug - and start it - its code 34 goes away - ur sensor is bad. If its still there - its wiring.

EDIT - as i was typing this u posted the resistor method.

when they arent torqued down properly they have an improper resistance - its a piezo elec crystal - so pressure changes voltage and resistance. either way - resistor mod

[s13pignose]

Either way i've got another issue besides the possibility of sensor. The wiring. Like I said there's some wire in the bundle that is messed up or something. I cut away the wire loom around that one particular area..but all the wires are packed together so tightly I can't move around to examine. It's all in that location I showed in the pic. I think I'm gonna leave well enough alone and let dude look at it thurs. It's a definite problem for sure.

[smelly240]

U can jump out the knock sensor by cutting the knock wire a few in from the ecu and soldering a 1 megaohm resistor inline with a wire to the chassis.

[supreme_1]

does anyone know what kind wattage 1 megaohm resistor is best?

[s13pignose]

I used 1/2 watt..right on the ecu wire plug..did the trick..but it's temporarily there. Plan to get another sensor soon