ECU Talk says my ignition timing is droping??((VIDEO))

[ShouldaHadaV8]

According to ECU Talk my car is idling at 750 , 20 degrees BTDC,
BUT when i hit the gas my ignition timing drops ,the car bogs and wants to stall unless i ease on the gas ,then i can give it full throttle but it doesn't give it all the power. and it keeps throwing code 34 ( knock sensor )
So my question is can the knock sensor affect the ignition timing this way, i've heard it only retards the timing up to 5 degrees and most people just clear the code. I have replaced every other sensor ,but im not sure whether or not replacing this one is necessary. I just want some input before i buy one because i have seen other people who said their car ran horrible until they changed the knock sensor.

[Sugar]

If you are throwing codes take care of the issues.

The knock sensor plays with timing, its more than likely your problem. You can bypass the knock sensor, see if the code goes away. This will at least let you know if its a wiring issue or the sensor it self. Put a 1M Ohm resistor in place of the sensor and see if the code goes away.

[ShouldaHadaV8]

If you are throwing codes take care of the issues.

The knock sensor plays with timing, its more than likely your problem. You can bypass the knock sensor, see if the code goes away. This will at least let you know if its a wiring issue or the sensor it self. Put a 1M Ohm resistor in place of the sensor and see if the code goes away.

but its alot easier to find out whether or not the knock sensor even has an effect on the actual IGNITION TIMING, i can replace it for $10 but i want to actually know if the sensor itself can mechanically cause the problem i am having? if i had to go buy a resistor and test to see if it works and blah blah i would just go buy a new knock sensor, this is why i thought i would ask just to see if the sensor has any effect besides retarding the timing by 5 degrees? either way its going to get replaced i just want to know if this is going to fix my problem.

[Sil240]

YES, The knock sensor does affect timing.
GO take care of that code first!!!
If it senses knock it'll pull timing.

[ShouldaHadaV8]

I already ordered one.. it should take a week to get here, we will see if it has any effect.

[Sugar]

A knock sensor is a b**** to change. Thats why I said to bypass it and see if the code goes away.

Nothing will effect the timing mechanically. The only thing that can be changed is ignition timing unless you physically change it...

[ShouldaHadaV8]

[ i want to actually know if the sensor itself can (mechanically) cause the problem i am having? ]
(electrically )

Nothing will effect the timing mechanically. The only thing that can be changed is ignition timing unless you physically change it...

so the knock sensor is the only sensor that affects the IGN. timing? I thought maybe it could also be the CAS sensor in the distributor ,but it didn't throw any codes besides 34

[ShouldaHadaV8]

Replaced the knock sensor, it didn't fix the problem. and the code still appears but i know its just from the bogging now.
I dont have a consult cable, i had another nico member hook up his and show me what was happening.
im stumped i've replaced almost everything now

[vancouverbc]

The ecu decides the optimal timing for the conditions so there are million things that could cause timing(you see on ecutalk) to look eccentric. sparkplugs, sparkplug wires, fuel filter, injectors. the possibilities for bogging are endless

[ShouldaHadaV8]

thank you because I understand that.
A) i don't have ECU talk, i had someone hook up for ten minutes and thats what we noticed happening.
B) I have already replaced sparkplugs, sparkplug wires, fuel filter, injectors,etc etc I have replaced everything I could possibly imagine could cause this problem, most sensors have been replaced (or tested with other sensors) new hoses, fuel filters, I looked for air leaks,I Haven't replaced the distributor/cap ,coil, or the fuel pump for the WAL.255 ( simply because I know they are working, and it worked fine on the last motor) or bought a reground kit.
C.) the possibilities are not endless although they are stacked against me it CAN be fixed and there ARE ways to find the problem through process of elimination. in this case the process sucks.
D.) I'm relatively smart I would say when it comes to motors, I am a certified airplane engineer, try dropping the engine on a BOEING jet.( it probably easier than a KA swap) and I have many friends who are mechanics which HAVE looked at this car and cant figure it out.

Everyone on the internet finds your tutorials for help on most everything 240sx. we can figure this out, something has to fix it.

[Sugar]

Does the car still have the knock sensor code? That code is no joke, it will rob your car of any performance.

Could the wiring be a possible issue? Check continuity with the knock sensor/ecu.

I had a issue with my knock sensor wiring. It felt like I was towing bus. the car had no throttle response, lots of hesitation.

[ShouldaHadaV8]

yes it does still throw the 34 code , the only problem is i am not sure whether its throwing because of the bogging below 650 rpms or if its a wiring problem. i have replaced all the wiring harnesses except the body harness which runs down the left side of the car. and i have replaced all sensors, and the ecu just to be safe

Im still waiting to buy ecu talk when i get paid this friday, im at the point now where i just stare at my car with a voltmeter in hand and think to myself PHUUUUUCK if i only know what was wrong with it I would pay to fix it. lol

if you have any suggestions i can get voltmeter readings and test anything you think may be the problem. i will see about the continuity with the knock sensor

[gaehrings13]

I know this sounds dumb... but the first thing I check when a car is bogging is the fuel pressure.. see if it is where its suppose to be at idle.. I had this same problem with my car a little while ago and I changed the pump and it still ran like crap.. Then I squeezed the return line to bump up the pressure on the injectors and the engine rev'd up good... So I changed the fuel rail with another one that I had, because I wanted to try another FUEL PRESSURE REGULATOR.. I did this and it works.. So the fpr was bad.

[Sugar]

yes it does still throw the 34 code , the only problem is i am not sure whether its throwing because of the bogging below 650 rpms or if its a wiring problem. i have replaced all the wiring harnesses except the body harness which runs down the left side of the car. and i have replaced all sensors, and the ecu just to be safe

Im still waiting to buy ecu talk when i get paid this friday, im at the point now where i just stare at my car with a voltmeter in hand and think to myself PHUUUUUCK if i only know what was wrong with it I would pay to fix it. lol

if you have any suggestions i can get voltmeter readings and test anything you think may be the problem. i will see about the continuity with the knock sensor

Follow the FSM procedure for testing the knock sensor circuit and the sensor itself. I want to say that code will put the car into limp mode, but I'm not for sure. Either way I'd say thats your issue, definitely take care of it before you try to continue diagnosing.

[ShouldaHadaV8]

I've been looking for the knock sensor section in the FSM for a while now. I cant seem to find it, If someone can find it or knows where it is please let me know.
AND now that I think about it, I used the 96 fpr?????? i know the 92 fpr was working, I will swap them to see what happens.
could be a 50/50 shot maybe its the knock sensor circuit, or maybe I just need to swap the fpr.
I will test the continuity for the knock sensor once i know how much it should be and where to test. if i can find my other FPR I will replace it in the next couple days.
LETS ONLY HOPE

[ShouldaHadaV8]

Bump
does anybody know where to find the knock sensor in the fsm? or does anybody know what the continuity of the knock sensor is supposed to be at the ecu?
and i found a few ecu pin layouts im not sure which one is right? http://www.s-chassis.com/resources/wiki ... oldid=prev
http://www.240sxforums.com/forums/ka24d ... ka24e.html
one says it should be purple but i dont see a purple one in that spot, and the other one is white but i dont want to post readings for something random, maybe someone can just tell me which color it is.

[ShouldaHadaV8]

ok so i tested the white wire( 27) for its continuity on a 9v load test, and got -0.06 pretty consistently. Is this good?

[ShouldaHadaV8]

My speedometer/rev limiter doesn't work, but you can hear it bog, still throwing code 34.
[youtube]http://www.youtube.com/watch?v=yiFS4wKxbKw[/youtube]

[90singleslammer]

i am having the same EXACT problem and i also could not find the knock sensor in the fsm

[ShouldaHadaV8]

Bump

Moderators please shed some light.

[ShouldaHadaV8]

Bump

Moderators please shed some light.

[ShouldaHadaV8]

Bump

Moderators please shed some light.

well in the mean time atleast I got to paint the car finally. no more black and gray primer, just flat black. it looks better I guess.
I still haven't got any response to my video though

[Sugar]

The problem is with the knock sensor or the knock sensor circuit, nothing more to say. If you can fix it yourself do it. If not, then pay someone to fix it for you.

If you are sure your knock sensor is good, then you need to check your wiring as the FSM states. Or as I said earlier, bypass the Knock Sensor with a resistor to see if the code is dropped, that will rule out the wiring.

No need to spam quote yourself. You know what the problem is.

[Sugar]

i am having the same EXACT problem and i also could not find the knock sensor in the fsm

http://www.phase2motortrend.com/nifasemaf.html

S14 SR (English) Also applies to S13 SR.

For Knock Sensor Diagnosis refer to EC 132 and 205 in the S14/SR FSM. (EC 132 = Page 268-270) (EC 205 = Page 340)

[ShouldaHadaV8]

You know what the problem is.

I beg to differ
I replaced the wiring harness from the ecu to the engine bay so I doubt its the same problem on two harnesses, although at idle mine is reading 0.06v at idle( but im not even sure im testing the right wire i think i am but i question the fsm ecu diagram) ,and even if the resistor fixed the code i wouldn't have fixed whats causing the original problem so i dont want to go that route although your right i could MAKE it work im sure . Maybe your used to splicing in resistors but i've never done it.
section EC says continuity should exist.... well mine is continuously 0.06 at idle. It doesn't specify to check throttle positions it just says running. on page ec-198 it says 2.0-3.0 volts ,so im really confused because i cant find any problems with the wires and im reading to low. i've been testing everything ,im really confused now
im not going to pay a "wiring specialist" F_ck that this isn't my DD its a learning experience

Man I couldn't even get a moderator to chime in with all the sub quotes.

[ShouldaHadaV8]

I noticed after watching my video over and over something which has been concerning me though. When I swapped the motor I used the same header and exhaust system that was on it but i didn't replace the headers gasket, I reused the old even though I knew I shouldn't ( I intended on buying a turbo manifold alot sooner) I just wanted to get it running first.
If you watch the video around 0:59-1:01 you will hear how loud the exhaust leak is. Now if i didn't know it was an exhaust leak because I can hear it upclose and know I didn't replace the gasket ,i would say it sounds like rod knock, although I am 100% positive it isn't. im wondering if the sound being so directly next the block is being picked up by the piezoelectric vibration sensor in the actual knock sensor? but im not sure if its possible because i dont know how sensitive it even is to that type of variable.

[Sugar]

I'm pretty sure a knock doesn't through a knock sensor code. If the sensor is working it will pull timing to eliminate the knock.

If you are getting code 34 then the problem is the sensor, the circuit, or there is a very slight chance that it could be the ECU.


You really are not understanding what I am saying with the resistor, im not saying to bypass the knock sensor and all is well. I'm saying reset your ECU, bypass your knock sensor and start it then shut it off, if it clears the code then the knock sensor is fautly, if it does not then it's most likely in the wiring.

But... your voltage is low, so you have found your problem. Check the ground for the knock sensor, make sure it's not grounding out with anything else.

As a last resort, re wire your knock sensor and ground it to the chassis.

[ShouldaHadaV8]

Thank Sugar for the proper answer
I think i have finally figured out the problem at hand
I ran the car for about 20 minutes after resetting the ECU and after turning it on and off a few times it seems like the factory fuel pump is definitely beginning to fail ( it sounds like i starting to grind and sputter). i bought a walbro255 so i can rule out the fact that its rpms are definitely going below 650 rpm which throws the knock sensor. fuel pump is one of the only things that i havn't replaced.

[ShouldaHadaV8]

so by reassuring myself its not fuel, i wont be if it has no effect. like i said i replaced everything else already so if a new fuel pump has no effect. its a guarantee that its the knock sensor circuit.

[ShouldaHadaV8]

I reset my ecu and let it run without touching the gas for around 10 minutes, shut it off and then tested the ecu for codes again and it came back 55. which is kind of reassuring me its the fuel pump.... because i know when i hit the gas it caused it to bog pretty low even shut off in a few cases, so im hoping it wont come up after I replace the pump. if it starts off running bad immediately after the fuel pump gets replaced i know its going to still be a wiring issue. The pump should be here in the next 5 days.