Ignition Timing Question.

[Daboss]

Hey forum hows it going? Here to ask the opinions of the experts again. What I want to know is if a dead clutch can affect ignition timing? My car is a 95 gts-t mods are 3.5" turbo back exhaust with split dump, fmic, pod with cai, bosch 040 fuel pump, iridium plugs gapped at .7, boost turned up to 12 psi and afc neo . Ok I was just trying to up my knowledge level, so I got a timing light and was looking to see where my ignition timing was. After the car was completely warmed and i took a look I noticed it was at the first white mark which means 5 degrees btdc now I'm no expert but according to the forum and threads I have read shouldn't that be at 15 also I turned the cas all the way anticlockwise to see what would happen and the mark moved from 5 to about 15 degrees btdc. Now the low side of my neo has been adjusted to take out some fuel. I just wanted to know does this weird reading signify a problem, is it cus of my afc neo adjustments or can it be my clutch as it is dead? If so what are my options? Also I already turned the cas back to its original position and its now back to 5 degrees btdc.

[Daboss]

So nobody has any idea or any kind of solution for this prob? Come on I know there has to be someone out there with some kind of opinion.

[blind_elk]

Don't know how you could come to the conclusion that a clutch (in any condition) could possibly affect ignition timing.

If you have a programmable ECU, then you have to calibrate it (tell it where TDC is) before setting base ignition timing. You also need to be aware that some timing lights can give incorrect indications.

[QWK32]

did you disconnect the aac valve before taking the reading, at what rpm did you take the reading? and where did you take your signal from?

base timing cant be changed by a safc neo. you cant indirectly affect the ignition timing added on by the ecu by taking or adding fuel with the neo but this will not change your base timing.

[Daboss]

did you disconnect the aac valve before taking the reading, at what rpm did you take the reading? and where did you take your signal from?

base timing cant be changed by a safc neo. you cant indirectly affect the ignition timing added on by the ecu by taking or adding fuel with the neo but this will not change your base timing.

Ok here is the deal when I took the reading the aac valve and tps was connected I took the signal from the first spark plug thats when I got the reading of 5 degrees or saw it at the first white mark and the rpm was around 780 -800. I then tried to advance it and the furthest it could get to was 15 degrees btdc or the third white mark so I put it back to where it was. I then disconnected the tps and the rpms went up to like 1180 and when I checked timing It was at the 4th white mark or 20 degrees btdc. I reconneted the tps rpms went down to 780-800 and it read 5 btdc i disconnected the tps rpms went up to 1180 and the timing read 20 btdc and i did this about 4 times with same result. With the tps off I decided to retard the timing a bit via cas so I put it to 15 btdc with tps disconnected and the rpms went to about 900 and when I reconnected the tps rpms dropped to about 700 and timing could not be read it was in front of the orange mark so i put it back to the original position. Like I said some fuel had been taken out via afc neo and I wanted to know if that what was affecting the ignition timing and if it indicated a prob or if this was a normal thing to happen. For it to read 5 btdc at idle.

[QWK32]

have you tried taking a reading from the loop in the coilpack loom at the back of the engine.

how does the car drive, how does it feel? have you had the cas off anytime lately, and put it back on like a tooth off???

[Daboss]

have you tried taking a reading from the loop in the coilpack loom at the back of the engine.

how does the car drive, how does it feel? have you had the cas off anytime lately, and put it back on like a tooth off???

Nah the cas was never off and no I only took the signal off the number one spark plug. A fair bit of fuel has been taken out of the low throttle side via afc neo, 21 to be exact. Could this have anything to do with the timing being so low at idle? Cant tell how it drives as I haven't driven it lately due to clutch being dead was just checking the timing of the car for experience and to make sure all was right for when the new clutch goes in this weekend. What does the rpm jumping to 1180 and the timing reading 20 btdc when i disconnect the tps mean?

[QWK32]

What does the rpm jumping to 1180 and the timing reading 20 btdc when i disconnect the tps mean?

just means your base idle is abit off, the aac valve fixes it up when its plugged in. when you engine revs higher your base timing readings get larger, they are also wrong. the base timing needs to be set at a certain rpm for the reading to be correct.

at what rpm are you taking that much fuel out at? it doesnt really matter at idle because the ecu runs on closed loop and does its own correction.

[Adriano]

Why dont you try zeroing the settings on the NEO and then check the timing

[Daboss]

just means your base idle is abit off, the aac valve fixes it up when its plugged in. when you engine revs higher your base timing readings get larger, they are also wrong. the base timing needs to be set at a certain rpm for the reading to be correct.

at what rpm are you taking that much fuel out at? it doesnt really matter at idle because the ecu runs on closed loop and does its own correction.

ok the rpm tht the fuel comes out at is idle which is 800 with acc and tps connected. Just to know I never disconnected the acc only the tps, as stated by the manual. So you think that because so much fuel has been taken out that is why timing is so low cus at that -21% correction I advanced the timing via cas as far as it would go and the reading only came up to 15. Also whenever I disconnect the tps idle goes up and when I reconnect it idle goes down I tried to fix the idle but my ecu does not have the adjustment knob on it, neither the red light, or any kind of light for that fact, that shows error signals. So I just adjusted using the idle screw and got it to as close to 900 as I could and with the tps off that worked out to be 1180 rpms.

[QWK32]

i cant see why you would need -21% correction at idle have you tried taking the low throttle correction untill about 2000rpm back to 0% and see what happens. and have you tried a different timing light?

also in the sensor check screen on the neo what does it say your tps voltage is?

Edited November 19, 2007 by QWK32

[Daboss]

i cant see why you would need -21% correction at idle have you tried taking the low throttle correction untill about 2000rpm back to 0% and see what happens. and have you tried a different timing light?

also in the sensor check screen on the neo what does it say your tps voltage is?

I just did it awhile back as when at idle with the neo being to 0 my wideband read afr's of 12 after warming up for 10 mins so I took out fuel until it read 14.7, no I didnt take a reading with the neo at 0 will do tomorrow and no I have not tried a different timing light have to find someone with one first. I will try taking a reading with the neo at 0 tomorrow when I get a chance. If it does advance it back to 15 btdc do I leave it there, does it being at 5 btdc endanger the engine in anyway on the low side of the neo, does having the low side of the neo that much retard affect the hi throttle side of the tune? If I were to advance my timing to 20 and still tune my neo for 12 afr's do i risk damaging my engine? Just to know I always run 100 octane fuel. Will also check tps voltage.

Edited November 19, 2007 by Daboss

[meet07]

Revive from the Dead!!

Did the problem ever get fixed?? Im having the same issues. My car idles at 1000-1100 and when I checked my timing, it was way pass the "O" mark??

[Adriano]

Do a diagnostic check, the ecu is retarding the ignition timing to try and drag the idle speed down

[meet07]

Do a diagnostic check, the ecu is retarding the ignition timing to try and drag the idle speed down

But why?? That makes sense but what could cause the ecu to retard timing?? I did a diagnostic check the manual way and only got code 55. I have a nismo thermostat that opens at 150 degrees. would that cause any issues?