I just took my car into my dealership to have the rear O2 sensor replaced. I figured I'd have the service tech advance my timing to 17 degrees BTDC while it was there. The tech said he tried to advance the timing. But every time he restarted the engine, it automatically reverted to the default setting (15 degrees BTDC). Any of you guys have a guess as to what's going on here?

 

stopped and re-started the engine several times and it held to +17.
Maybe I need to go back and check what it's at now...

Were u there watching him do it and if yes, can you describe how he did it?

 

I called the tech, Galo. Apparently he didn't know you could set the timing with the Consult. (G-d only knows how he was trying to set the timing without it!) Now the dealership wants to charge me $80.00 to advance the timing. Needless to say, I'm not a happy camper, particularly as they presumably had the Consult set up when they replaced my defective O2 sensor. But I can't complain too much. They replaced the sensor in my Cattman Y-pipe without so much as blinking an eye.

Win some . . . lose some . . .

 

i got in touch the guy i know and he said they did not disconnect his tps before advancing the timing. his is still set after 8 or 9 months. i assume the tech did disconnect the tps?

 

I'm not certain what the tech did or didn't do at this point, sloppymax. I've got my Service Writer looking into it. What bothers me is that I specified in my written instructions to the dealership that the Consult was to read +2 degrees after the timing was advanced. It's difficult for me to understand what part of that instruction the tech didn't understand . . . unless he failed to read it, of course.

No matter what happens, I've already told my Service Writer that I'm not going to raise a stink about this. After all, it would have been easy for the dealership to void my warranty on the O2 repair with a Cattman Y-pipe staring them in the face. And they didn't charge me anything for attempting to advance my timing. So I basically told him that I'd leave the decision up to him. We'll see what develops from here.

 

is WAY too much given it's a 15 minute (max 20) job.
Agree w/u...see where it goes from here.

 

If you pay the $80, print this and tell him you want a print out like this one:
http://forums.maxima.org/showthread....timing+advance

That way he will know what he is looking at. Trust me, I went through the dumbfounded look when I got my ECU reprogrammed. They don't get too much time to play with the Consult, I guess.

I'm still hoping someone can convince their Tech to meet them at a dyno and change the timing. Now that would answer a BUNCH of my questions. I kick myself, since I actually had the Tech come to my work to reprogram the ECU.

I sure wish I would have known about the 'advance timing mod' then.

BTW, I believe it is possible to advance the timing further, but it will require performing an "Idle Air Volume Learning" procedure once it's set at +3*. I believe you can then go to +5*, which is still within spec. Just an idea.

Idle Air Volume Learning Procedure:
-----------------------------------
Pre-conditioning
1)Battery voltage > 12.9V(At idle)
2)Engine coolant temp: 70-99*C(158-210*F)
3)PNP switch = ON
4)Electric load switch = OFF(air conditioner, headlamp, rear window defogger)
5)Cooling fan motor = OFF
6)Steering wheel = Neutral(straight-ahead position)
7)Vehicle speed = stopped(no duuuuh!)
8)Transmission = warmed-up(A/T drive until "Fluid temp SE" in "Data Monitor" mode of "A/T" system indicates < 0.9V.(M/T drive for 10mins.)

Operation Procedure
1)Turn ignition switch "ON" and wait at least 1-second.
2)Turn ignition switch "OFF" and wait at least 10-seconds.
3)Start engine and warm it up to normal operating temperature.
4)Check that all the items under "Pre-Conditioning" are correct.
5)Turn ignition switch to "OFF" and wait 10-seconds.
6)Start the engine and let idle for at least 30-seconds.
7)Select "IDLE AIR VOL LEARN" in "WORK SUPPORT" mode.
8)Touch "START" and wait 20-seconds.
9)Make sure that "CMPLT" is displayed on CONSULT-II screen. If "INCMP" is displayed, "Idle Air Volume Learning" will NOT be successful.
10)Rev up the engine two or three times. Make sure that idle speed and ignition timing are within spec..

Spec:
Idle Speed - M/T: 625+/-50rpm, A/T: 700+/-50rpm(in Park or Neutral)
Ignition Timing - M/T: 15*+/-5* BTDC, A/T: 15*+/-5* BTDC(in Park or Neutral)

 

If anybody is in CO I can get it done for 10 bucks. If any body lives in Denver or passing through drop me an IM

 

I'm going on saturday to get my timing advanced. I'm hoping I'll get some time to talk to the tech. If anyone has any questions I'll try and ask them. Keep in mind, I'm no Ice. If the questions are really technical put them in this thread and I'll print them out.

Ice, thanks for all the info you've provided on timing advance.
I have two questions for you.

In the other timing advance thread the information you provided seems to indicate that advancing the base timing would have little effect, yet you had yours advanced. Did I misunderstand?

In your reply in this thread you mention having your ECU reprogrammed. Did you make any other changes to your ECU?

Thanks

 

what does this do for ur car???

 

When you press the "Go" pedal, it goes...faster

 

And it improves your midrange power, not so sure about the higher end though...

ED

 

more noticeable in the mid-range, say from 2k to 4k rpms
Slight fuel mileage improvement as well...when I ketp track of the fuel mileage (on five fillups after the advance) I got .8 better mpg.
Within statistical variations? Maybe, but they were weeks just like any other....
galo

 

you guys are GREAT. Thanks in particular to Galo and IceY2K1 for all your info. I'm going to fax a copy of the Consult printout for the Timing Adjustment to my Service Writer this morning. I'll let you know what he decides to do.

 

That is not within engine spec, so it will not be safe.

I have 235/45/17s on my stock rims

 

 

How do we get our hands on a Consult II? Nissan's got to be buying them from somewhere. If we could get a few, pooling our money, we could bounce them around for a deposit with a small rental & shipping fee to go to the org.

 

They cost ~$4K and according to another thread it may be possible to reprogram the Odometer, so IF that's true, it isn't going to be easy.

I have my eye out though.

 

That's just one arguement and it's NOT necessarily correct.

You can still see an improvement in the lower RPM range. How low I don't know, but according to those that have had this done, it's worthwhile.

My timing is stock, I don't think my "Service writer" would know what I was talking about and I'd have to come up with an excuse to get the Tech alone.

I only have the Fuel Cut TSB reprograming done.

 

Yes it is within engine spec.

So do I.

Do you have anything else of value you'd like to add, Cutlr7?

 

It was a joke, calm down. You use to get on people all the time. sheesh

 

Thanks, I just assumed that your ECU programming included a timing advance. I was hoping you came with a few other ECU changes to bump up performance.

 

I got my Service Writer to agree to advance my timing. He's going to charge me for 1/2 hour of the shop rate, or $40.00. He said that his lead tech did some research and found out that 3 degrees of advance is the MAXIMUM amount permissible under CA statute. I'm not sure if that's right, but it really doesn't matter. I told him I wanted to keep my timing in-spec and not to increase it beyond 17 degrees BTDC. It's set at 15 degrees BTDC right now.

I'm having the work done on Saturday. I'll let you know how it turns out.

 

Maximum permissible under CA statue? It does increase emissions, but also increases fuel economy and power.

Sounds like great news, let us know how it goes.

 

is 18 defined as out of spec? ive seen some base at 14 then others at 15. if youre at 14, i assume 17 is within spec, if youre 15 then 17 is still the highest to be in spec?

 

No.

Spec:
2000 15*+/-2*
2001-2K3 15*+/-5*

I have no idea why the 2000 and the 2001s would be any different, but they are.

 

maybe fed vs. cali emissions standards. thats the only difference i can think of.

 

done, you'll have my full attention!

 

So, I could increase my 2001 timing to 20* and be within spec and gain low end torque for half an hours work at a dealer (roughly 20-30 bucks)? Doesn't seem like a bad deal to me...

 

That was my guess, however someone here on the board stated their 2000 ESM was for both fed and cali emission cars which listed 15*+/-2*.

I'm pretty sure if it will work on a 2001 Cali emissions car, it would work on a 2000 whatever.

 

is feasible...in one hot day in September (to us, a hot day is low nineties) and after a good heat soak in good Saturday city traffic I noticed a very brief instance of very, very slight pinging when I laid into it a bit in 4th gear going up Sylvan hill (Portlanders will know, for others a good 6% incline four-lane highway, limited at 50 MPH but where 55-60 is the norm going uphill) and that with 92 octane Chevron so...go much beyond 17 degrees & you might run into pinging in hot weather...

 

A/C on? WOT?

With a full load and you lugging it in 4th at 50-60mph that is NORMAL and perfectly fine. IF you weren't lugging it, the knock sensor would have pulled the timing BEFORE you ever heard pinging.

If you were NOT at or close to WOT, the ECU actually attempts to run lean at part-throttle for emissions reasons. Then you lug it and you will have pinging.

y2kse is ONLY going for +3 anyways(17*BTDC).

 

to maybe 70% throttle...wife, daughter & I in car and it was very very brief, almost imperceptible.

From that which you describe, it could be that it was completely normal...

 

I agree 20* is most likely overkill, but if it's within spec the ECU will be able to compensate/override if things get bad.

I doubt the difference is going to be noticeable, but we don't know until someone tries or we get a Consult on a dyno. So far, nobody that has the advance timing mod has even been able to go that far advance, so it may not be possible.

I just hate the fact that mine sits at 14*BTDC, when it SHOULD be at least 15*. However, I'd rather have 14*, than 10*.

 

Nope. The knock sensor cannot see into the future. It can only sense knock AFTER it happens. Then it pulls the timing WAY back. That's why it's better to time the engine to NEVER knock. Because if the ks kicks in, it will pull it back much futher than you just advanced it.

 

Not see into the future!

The knock sensor will register the pinging before it's loud enough for you to hear it.

 

Then why did he "hear" the pinging? Probably because the ecu couldn't pull the timing back enough. I agree though the ks should start pulling the timing back before we hear it.

 

Normally the pinging is squelched by the ECU faster than we can pick it up over road/cabin noise. However, under EXTREME conditions such as I suspect here, he was lugging it with a full load, the ECU is not going to compensate quick enough.

Every engine management system is different, but typically unless there is something extreme happening(fast transition), the ECU should read the knock and compensate through whatever means necessary.

 

...I was doing maybe 50 in 4th...that's in the realm of about 2500-2600 rpms! Granted, I was'nt doing 4 grand but...lugging it is under 2k to me
)

 

Hey guys,

I just had my timing advanced and I wanted to report my observations. The car has 1500 miles on it, I also had my oil changed at the same time, and the car is bone stock. The tech said my car was set at -1 and he bumped it up to +2.

Here's what I noticed and I hope it was not a placebo effect.
I felt a noticeable increase in power but felt it most strongly in midrange 2500-4000. It's a little hard to do low rpm WOT runs in NYC so that may account for the fact that my midrange increase felt stronger than my low end.

Ok, the other strange thing which I have not seen people report is that the car seemed to pull harder to redline. Also the car seemed to downshift more aggressively. I don't know how to explain that.

As far as holding the timing when the battery is disconnected this is what he said:
The timing will not reset if the battery is disconnected for a short time. As a matter of fact the timing should only reset if the battery is disconnected long enough so that the chip in the key won't work.

I really want to see what y2kse has to report.