[Ninety-Nine SE-L]

OK, I asked this a few times before but no one really knew. After some thinking I came up with some possible situations. Tell me what you guys think.

Ok, about a year ago, when I was still new at this car stuff, I went to a local Nissan Performance shop to advance my timing to 15*. When I went I had a full tank of premium gas to be safe. After a few minutes of work, the guy said it was now at 15* and yes, there was a power difference. a few months of driving it I didn't notice any change, but with the gas prices rising (b/c of 9/11) I started using lower grades of fuel. eventually, I tried regular grade (hesitant at first) and driving it around, I got no pinging at all. I thought this was strange being at 15* so I went out and bought myself a timing light (I had more experience now) as I pointed it down to the pulley, it read out 7-8*!!!

7-8*!!! what the heck!!!!! so I got out my wrench and advanced the distributer cap a little...still 7-8*. Turned it more...the same thing. Eventually I got as far as it would go and still no change (no pinging either). So now I can't advance my timing....

BTW, when I retard the timing, all I get is a strange drop in the power band between 5 and 6,000rpms. and it is a big drop, I feel like there's no acceleration in that area of rpms.

So anyway, now I'm driving around with my distributer as far forward as it will go and I sit at 8*. Is there anyone that can tell me howw to make my timing go back up to 15* again? My guess is it's the ECU. as far as I can tell every time I try to advance my timing, the ECU counter acts it with a timing decrease. Could I have a bad knock sensor?

 

[James]

did you unplug the tps when you advanced the timing???

 

[Ninety-Nine SE-L]

yeah

 

[James]

are you running 91 again?

 

[Ninety-Nine SE-L]

no, I'm back at 87.

 

[James]

you have to run 91 or the knock sensor will retard your timing....

 

[Ninety-Nine SE-L]

Sorry, my computer crashed as I was trying to reply............
anyway, so by what you're saying, If I were to put 93 octane (we have 93 in FL) and checked my timing, I would be back at 15* just like that?

 

[James]

yeah, it might be at like 150 by now... you might want to have someone put it back to where it was so you can start from scratch... when they say you have to use premium gas, you have to use premium gas!

 

[Ninety-Nine SE-L]

yeah, I know about that, but when the gas prices went up I figured I would experiment with a lower grade. I figured I'd go until I got pinging. Guess that was a bad idea.

Well, that actually sounds pretty cool, whenever I wanna race I just put in some octane booster and voila, an extra 5 or 6 hp. LOL

thanks I'll try upgrading next time I fill my tank.

 

[James]

if you want to run 87 you should go back to stock settings... you can't run it all the time with crap gas and expect no damage to the engine.