ECU adjusting timming? and other questions

[poshatch]

so every once in a while i get something up my butt and i start doing rediculous amounts of research into any thing and everything having to do with my car, my engine, suspension, motorsports, etc...and my latest thing has been the EGR system

this lead me to ignition timing in that smog shop said i was running 14* BTDC of ignition timing, however, ka24de stock ignition is 20* BTDC, and at the time my knock sensor was malfuctioning (code 34), and that it can retard the timing up to 5* and boo ya that would explain why i was at 14* (if i was at close to 20 to begin with)

i want to be running 20* minimum if not slightly higher to give the fuel more time to burn and less unburned fuel means more power + less pollutants comming out of my tail

1. in looking around the forums online and google i found contradicting info, just to be sure 100% sure, advancing the timing (i.e. 20* to 25* BTDC) is turning the distributor clockwise (towards the back of the car) and retarding the timing (i.e. 20* to 15* BTDC) is turning the distributor counter clockwise (towards the front of the car) right?

2.how does the ecu adjust the timing as in when the knock sensor is malfuctioning and it retards the timing? im not quite understanding this because it seems to me that i can adjust the distributor all i want and the ECU can just change it right back to a point that i dont want it to be at...plus i dont see any way in which the ecu can change the actual spinning of the rotor in any way...

i was about at the middle of the distributor running 14* and i turned it all the way clockwise hoping to advance it, it felt like it ran a bit better as far as i could tell, no bad noises, sometimes the idle would dip (trying to get ahold of a timing light)

3. im begining to think there is a wiring issue distrupting the signal to the ecu or the ecu itself is malfunctioning because my EGR system is fucntioning properly (egr valve does and open under vacuum and close durring idle, and the solenoid has to be working since its connected to the scv solenoid and if that malfunctioned then the swirl solenoid which i disconnected while running and it sorta died because i believe its connected to the FPR)

going to either borrow or buy a voltmeter tomorrow and do the tests at the connector and the ecu per fsm instructions and see if i can locate the problem, if that checks out and the valve works and the wiring works ill replace the ecu if that dosnt work then the solenoid, after that......i just dont see anything that would be malfunctioning if the ECU, Wiring, Solenoid, and Valve all work correctly

sorry this is so long just being torough to get these questions answered

[zenkistic]

bump. interested in replies to his questions. I am soon gonna try to retard my timing by rotating the distributor to stop misfiring.

[ka-t4u]

does your check engine light come on for code 34?? am also very interested in this topic!! as my check engine light doesn't come on but when i turn the ecu to diag mode it displays code 34..... :/

[poshatch]

i think some vehicles it does come on and some it does not, from what ive read, and when i swapped everything over and the check engine light came on and it only read a code 34, and then after i reset it and drove it around some it would be 32 and 34

does your check engine light come on when accessory is turned on? also there is a procedure in the fsm to check the light for malfunctioning i think

somebody with knowledge on the subject please chime in!!

[zenkistic]

[threadjack]
about the engine light.
Mine is not coming on at all. I just checked the fuses in the kick panel, they are ok... What can be the problem? ASAIK the car has not been tampered.
[/threadjack]

The original questions still need to be answered, come on guys!

[poshatch]

go here:

http://www.nicoclub.com/FSM/240sx/91-94/EC.pdf

section ef & ec

page 41, it should be the bulb test diagnostic

start with that, its probably a blown bulb and needs replacing, shouldnt be too hard to find one

and yes please somebody answer the questions!!! there are many many people on here who are very knowledgable with nissans and 240s so i know somebody knows!

[zenkistic]

thanks, and bump for a question that is of my interest as well.

[poshatch]

bump bump bump, this i know there are smart people on here where are you! please restory my faith in NICO after nobody could answer my solenoid question

[some_white_guy]

man i wish some1 would answer this question, i'm curious about turning the distributor as well

[poshatch]

yeah i wish i didnt find contradicting info

like i saw this:



but then read on another forum one person saying it is this and the other saying it was hte opposite so i just want to be sure, best to take a light to it but im still curious about the ecu adjusting the timing (like when its knocking) and my other questions errrr

[Calizzaran]

Just had my KA24E SOHC timing adjusted thanks to Smog it was at 21* and my mechanic adjusted it from the Distributor just like shown to 15* which was normal. He just loosened the top bolt and pushed the distributor back a bit and went to 15* hope that helps.

[poshatch]

so what your saying is he did the opposite of the picture above?

[poshatch]

bummppppppppppppppppppp

[abstractjunction]

be careful when adjusting ur timing on the dist. advancing it indeed feels better has more response and power but it also equals more wear and tear and shorter engine life

[poshatch]

well i need to smog it so i want it at stock 20* for now and then i was only considering advancing it to like 23* which isn't that far advanced later on or just keeping it at stock. i'm not too concerned with gaining power out of this sort of mod so im cool with stock i just know that 14* is wrong wrong wrong

and my questions are still unanswered peeps:

1. advancing the timing (i.e. 20* to 25* BTDC) is turning the distributor clockwise (towards the back of the car) and retarding the timing (i.e. 20* to 15* BTDC) is turning the distributor counter clockwise (towards the front of the car) right?

2.how does the ecu adjust the timing as in when the knock sensor is malfunctioning and it retards the timing? im not quite understanding this because it seems to me that i can adjust the distributor all i want and the ECU can just change it right back to a point that i dont want it to be at...plus i dont see any way in which the ecu can change the actual spinning of the rotor in any way...

[kouki munster]

1. Get a timing light, hook it up, and then turn the dizzy if the timing changed in the wrong direction turn the dizzy the other way.

2. The ecu controls the signal that tells the coil to fire based on the signals it is getting from the cas(most important because this one tells the ecu where the engine is in the combustion cycle) and various other sensors. The ecu doesn't know what the timing is set at mechanically, all the maps in the ecu that determine when to fire the spark plugs are based off the base timing being set at the factory spec. Basically this means that if you advance the timing 1* it will be advanced that same 1* under all conditions, because the ecu doesn't know that you mechanically added 1 more degree of timing by turning the dizzy. The ecu will also only retard the timing below what the ignition maps call for, when it gets a signal from the knock sensor that tells the ecu that there is a high amount of knock, or the sensor itself is determined to be bad by the ecu.

Also look in the fsm for the procedure to set the timing, usualy you have to unplug or jumper something to let the ecu know to lock the timing so it is not adjusting it while you are trying to get it set correctly.

[poshatch]

1. Get a timing light, hook it up, and then turn the dizzy if the timing changed in the wrong direction turn the dizzy the other way.

2. The ecu controls the signal that tells the coil to fire based on the signals it is getting from the cas(most important because this one tells the ecu where the engine is in the combustion cycle) and various other sensors. The ecu doesn't know what the timing is set at mechanically, all the maps in the ecu that determine when to fire the spark plugs are based off the base timing being set at the factory spec. Basically this means that if you advance the timing 1* it will be advanced that same 1* under all conditions, because the ecu doesn't know that you mechanically added 1 more degree of timing by turning the dizzy. The ecu will also only retard the timing below what the ignition maps call for, when it gets a signal from the knock sensor that tells the ecu that there is a high amount of knock, or the sensor itself is determined to be bad by the ecu.

Also look in the fsm for the procedure to set the timing, usualy you have to unplug or jumper something to let the ecu know to lock the timing so it is not adjusting it while you are trying to get it set correctly.

lol well i guess ill just have to find a timing light to get the answer to number 1 since nobody remembers which way they turned theirs when they timed their car. that dosnt bother me

and what you said to 2 makes sense as well, so the ecu sends a signal to the ignition coil and it recieves that pulse for every ignition and then that is sent to the distributor cap center and then when the cap hits it it goes threw the wire to the spark plug, ok that makes sense, so the ignition advances when the rpms rise and i guess a change in pulse to the distributor itself could advance it. also i guess adjusting the base ignition timing also changes the power band a bit dosnt it, since the sweet spot durring the power band will change when the computer advances the timing

and i have read the FSM procedure on setting the timing and i will read it again when i get my hands on one to do the actual thingy

good news so far, swapped ecu to the one that came with the car (but not that engine) and the light has stayed off going to driive it a week to see if it comes on again before i attempt to resmog it to give it time to read any mistakes

thanks for the input on 2 that helps alot, probably a good idea to clean and regap my spark plugs too since they are slightly old and are gapped to the max of the standard range for the ka24de or a little over

[poshatch]

ok so my friend brought over his timing light, now it isnt the greatest gun mind you but from what i noticed the picture i posted is correct

i alos noticed the ecu adjusting the timing while i was tryign to time it with the tps in but the reading was way off when i tried doing it with the tps out so i did the final setting with it in, it stayed at 20* for the most part so im thinking the timing is pretty much close to 20 +/- 2* which is spec.