Ignition Timing Fluctuates

[Rekin]

Hey,

I have this problem in my car where the ignition timing tends to retard it self when driving. You can feel it pulling back and then jumps back to normal.

When i start the car in the morning and go for a drive (engine temp below 50degree's) the ignition timing sits on 7 degree's when im applying constant throttle. After releasing/pressing accelerator it fluctures but once constant rev's it jumps back to 7degrees.

It stays like this until it changes out of cold startup mode (whereby the rev's drop and the car feels fine; usually when it hits 60degree's)

During this whole time my O2 sensor voltage stays at the maximum 2.55v out of 2.55v when constant acceleration. Once i press/let go of accell the o2 sensor voltage fluctuates. It doesnt seem to fluctuate when cruising which ive heard o2 sensors are supposed to? instead it sits on the maximum voltage...

Ive noticed this after my mechanic replaced the o2 sensor but want to confirm if it is linked to. O2 sensor cost me $100, not keen to buy another to check...

Another problem which i think is also linked to it is if i turn on the car when the engine is hot (turn on engine after 10mins of turning off) The car starts misfiring, revs start fluctuating between 400-800 and the timing retards it self quite heavily as soon as i take off. Once i pass 3000rpm in first gear the pulling feeling goes away and the car returns to normal...

This also occured after the o2 sensor replacement, but want to confirm if this is all linked to it...

Would love any help

Cheers

[aleks]

So you are using consult to get your timing reading and O2 voltages?

The O2 voltage should stay between 0-1V. A factory O2 sensor is narrow band and don't go higher than 1V or 0.9V

At idle you should be at about 14.7 afr ~ 0.4V. so something there doesn't sound right.

[Rekin]

So you are using consult to get your timing reading and O2 voltages?

The O2 voltage should stay between 0-1V. A factory O2 sensor is narrow band and don't go higher than 1V or 0.9V

At idle you should be at about 14.7 afr ~ 0.4V. so something there doesn't sound right.

yeah im using a blitz rvit to read all my ecu sensors through the consult port.

My previous o2 sensor stayed below 1V, this one reaches a max of 2.55v

I'll check the AFR reading next time im in the car.

Are there any other ecu readings i should look into to diagnose my problem?

[aleks]

How will you do that with what meter?

[Rekin]

reading the service manual, the diagram says the ignition timing is affected by;

- crank angle sensor

- engine temperature sensor

- knock sensors

Seeing as the problem goes away after the car warms up but comes back when turned on when hot, it could be my engine temp sensor playing up?

[Rekin]

When cruising my ignition timing sits on 7degrees, as soon as my water temperature hits 65degree's the ignition timing jumps to 35degrees~ and feels normal whilst driving.

Does anyone know what could be causing this? Is this normal?

Thanks

[White GTS-T]

It's normal. The car will run R n' R when it is cold.

[NewKleer]

your o2 sensor isnt wired correctly from memory if ur getting 2.55v, the sensor wire is hooked up to the heater element power or similar.

[Rekin]

It's normal. The car will run R n' R when it is cold.

mm yes it does run RnR when its cold but its never dropped to 7deg constant over the 2yrs ive been driving it. Now it feels much more pulled back. Just wanted to make sure that 7degree is the value it drops to when temperature is below 65degree's...

your o2 sensor isnt wired correctly from memory if ur getting 2.55v, the sensor wire is hooked up to the heater element power or similar.

yeah the o2 sensor hits a maximum of 2.55v but usually stays above the 1.00+ value. It does drop to around 0.67~ but i dont like how it has such a large range up to 2.5v

It is a NTK o2 sensor and assumed they make direct replacement o2 sensors...

Would you happen to have any information on the wiring of the o2 sensor?, might double check if everything is correct

Thanks

[NewKleer]

theres no standardised wiring of o2 sensors due to all the variations so im not sure - on some cars white is sensor, blacks are heater, on other cars theres 3 different colours, and so on.

its probably 1 of 2 things - either wires are messed up, or the sensor doesnt have good electrical connection with dump pipe/ground circuit etc and theres more resistance to ground than there should be.

if the o2 sensor didnt come with a proper connector on it and there was splicing of wires or anything like that, i would say thats most likely cause

[Rekin]

theres no standardised wiring of o2 sensors due to all the variations so im not sure - on some cars white is sensor, blacks are heater, on other cars theres 3 different colours, and so on.

its probably 1 of 2 things - either wires are messed up, or the sensor doesnt have good electrical connection with dump pipe/ground circuit etc and theres more resistance to ground than there should be.

if the o2 sensor didnt come with a proper connector on it and there was splicing of wires or anything like that, i would say thats most likely cause

Thanks for the help, appreciate it.

Ill double check the wiring tomorrow in the daylight and see if it matches up. From what ive read, there are 2 heater wires and 1 sensor wire. Bother heater wires are same colours on both the o2 sensor and the connector on the car. Just got to match up the unique colour wire on the o2 to the unique colour on the car connector.

Also, seeing as you program/build consult reading units, does 7degrees ignition timing sound normal on cold engine cruising (below 65degree's?)

Cheers

[NewKleer]

on its own its not something id be worried about. i know on my car the timing is stuck at 5deg up to around 2300rpm till the car hits ~72C or so, then its normal. i believe its intended, just like the cold start enrichment is, just to make the car run better until its warm.

[Rekin]

on its own its not something id be worried about. i know on my car the timing is stuck at 5deg up to around 2300rpm till the car hits ~72C or so, then its normal. i believe its intended, just like the cold start enrichment is, just to make the car run better until its warm.

no worries, thanks for that.

Just trying to find a relation to why my ignition timing retards after a hot engine startup.

Will check out the o2 sensor tomorrow and see if anything changes, thanks

[Rekin]

yanked off my o2 sensor, its a NTK OTD2F-2B.

Has 3 wires; red,white and black and a plug.

Is this a suitable o2 sensor for RB20?

I see website's stating its a GTR o2 sensor, did my mechanic buy the wrong o2 sensor?

Thanks

[White GTS-T]

My genuine Nissan o2 sensor says 'NGK 205 Japan' and has a red, white and black plug. I'm not sure if the wiring for the o2 sensor is the same for the GTR and GTS-T but i do know that the GTR uses Zirconia o2 sensors and the GTS-T does not.

The o2 sensor voltage should be between 0.00 and 1.00v. It should not exceed 1.00v.

I would think that the ECU is running RnR (more so than normal) because it's not getting the correct 02 sensor signal/input. Your best bet would be to get a genuine replacement from Nissan.

[PUDZ 32R]

i recently bought an oxygen sensor for my RB20 and it is the universal fit one to suit EL falcon. seems to have made a good difference to my fuel economy as i am now getting 530km to a tank on 98 at highway driving including overtaking. old one gave me about 380km to a tank. i dont know any of the voltages but when i hooked mine up i bought a 4 pin plug from supercheap and just cut the old factory plug off and replaced the whole lot. there was 2 brown wires an one heavily shieled one which i assumed was the ecu signal. i think your o2 sensor is wired up wrong or is the wrong one. mine is a TRIDON FORD EL replacement P# TOS016 supercheap P# SP100905 got it for $95 inc discount. my car is doing much the same crap as yours still and it gets worse when i run it on 91 or other low octane fuel. im putting it down to the knock sensor but i dont know where it is. sometimes car runs like a shower of shit then it will suddenly lose power and struggle to overtake and refuses to rev out to 7800. gets there eventually but feels slow so i put it down to the timing being retarded by the computer. i think you should change your o2 sensor again mate as you will get crap economy if it isnt working.