Hi All,

 

Just tying up a loose end. I changed the TPS around about the same time my timing started going screwy and my car detonating.

 

Checked the settings at the TPS connector (had been reading from AVC-R) and they came in at about 0.45 while closed and 4.55 when full throttle. I had to drop the closed voltage to 0.285 V (about as far as it would go) to get the reading to 4.1V when open - anyone able to confirm that these results are ok?? - I'm wondering if I've installed a dud TPS.

 

TIA!

 

RobH

You should really be on 0.4v at close at 4.0 at open.

 

At 0.285 you car should be running like shite mate.

Have you checked for boost leaks, these usually raise the RPM a fiar wack. Get rid of the boost leaks and then put the tps back to 0.4 and you should be on a nice stable 750 rpm or there abouts.

Cheers Stu! Think I might chuck the old TPS back on and see what happens. I'm just trying to elimate TPS as a cause of ignition timing being out by a suspicious 15 degrees...

 

Anyone know what full advance is? Does it go by throttle position or RPM or combination?

 

Cheers!

i remember reading an old post on this and it said that as long as the voltage increased steadily from low to high that is all that counts. i think the higher voltage was just an average. i would set the lower volts back to 0.4 volts and not worry about the throttle open voltage. apparently the ecu compensates some how, by converting volts into percentages. i havent descibed this very well but someone will make it a bit clearer. it was a fairly recent post so do a search

FWIW I found my timing was out by about 15 degrees after a cam belt change. This came about through hearing detting, even in safety boost mode. I reset the timing on the CAS, and all seems fine. I've checked lots of times since, and no movement.

 

I would go for the "belt slip" theory (but not necessarily when running). Perhaps your belt was 1 tooth out BEFORE you changed it, and when you put the CAS back in the same place it would then be 15 degrees advanced!

 

This might explain why performance felt flat in a previous post of yours (i.e. it was retarded too much before, wrt cam timing?) I believe 15 degrees is roughly equivalent to 1 tooth out.

 

Point to remember - the ECU only tells you through Consult, etc. what the engine "thinks" the timing is, based on the mechanical position of the CAS. Its the mechanical adjustment of CAS that actually sets correct timing (not the ECU).

 

HTH

 

StuartR

Oh, and for the TPS I think between 0.4 and 0.5V closed (I set mine to 0.45V). Fully open I think the ECU gets a "Full Open Switch" signal, so the voltage is not so important (??? - could be wrong though LOL)

 

Check your throttle bodies for cleanliness, then adjust the TPS to between 0.4 and 0.5V, then reset the ECU and see what happens!

 

StuartR

 

p.s. anyone know how easy it is to just check timing belt alignment ?

Hi guys,

 

Thanks for the respone.

 

The old belt was timed up fine and yet the CAS was out by a long way. The new belt is also timed fine and CAS is still in the adjusted position. I see what you mean though Stuart, it was actually Nissan who installed the previous belt and timed the CAS and it worked fine for a year or so. It also worked fine before I first had it replaced. My only thought was that the CAS may have been set while the car was in safety boost mode and hence the ignition was retarded, 15 degrees advance would compensate if safety retard was 0 degrees...

 

What I hope to achieve with a ConZult is to see that the ignition timing advances and retards as it should (although I have to admit I can't find any info on what it should be doing). I have a nasty feeling it's stuck advanced somehow and I have adjusted the CAS to compensate.

 

Not sure if the ignition timing follows the same pattern as the VTC timing but if so it would explain why my low speed and high speed are a bit crappy but my (very short) midrange is a pleasant interlude.

 

If I can see that the timing is advancing and retarding correctly then I'll leave the CAS and spark timing alone as being 'good'.

 

AndyP - this may be of interest to you as I have a manual conversion. Ben also has a manual conversion and suffered the same 15 degree timing advance!! An old post I've just read says you have a drop in power at high revs since your conversion.

 

Can anyone point me to some information regarding ignition timing maps?

 

Cheers!

 

RobH

Whether I actually had a drop in power is debatable - the drive ratios are different and it was run on a different dyno on a different day, so who knows ....

 

Can't remember when I last checked my timing (it doesn't move does it!) and putting a different gearbox on the back of the engine will make no difference whatsoever to the cam/ignition timing on the front. I may be tempted to go and check it now though ...

 

 

Originally posted by RobH

AndyP - this may be of interest to you as I have a manual conversion. Ben also has a manual conversion and suffered the same 15 degree timing advance!! An old post I've just read says you have a drop in power at high revs since your conversion.

The thought that crossed my mind was that the timing might be out as a symptom of some other incompatability or different sensors/readings from manual to auto....

 

I'm not suggesting that your timing might be out Andy - mine was out by a very large, obvious (and suspicious) margin. But your possible drop in top end power since manual swap rang bells for me.

 

Cheers!

 

BTW - I thought it didn't move too!!

BTW - I thought it didn't move too!!

 

I hope you're not ripping the p*ss :p

Moi?! - LOL, Stu, that was for AndyP

 

Nah - just that you would think static timing would be static...only explaination I have so far is cas slipped or drive from cam has slipped...