settin timin with high idle

[tombola]

as with most gti rs mine idles at 1400 rpm
for those of us who cannot lower idle to 900 rpm to set ignition
timing wot r we supposed to do like is there a setting to aim for
or get some one to bring the revs down with the aid of the clutch
while i check and adjust [b4 the clutch burns out] the timing ?

also when i unplug TPS revs rise further
at the moment i have it set at 18/19 degrees bftdc @1250 rpm ?
but the dizzy is nearly at full adjustment ie top of dizzy is going
towards back of the car clockwise like

since setting it to this its developed a misfire through out most of the rev range? but not too bad it still pulls well though 8) :?:

 

[jasegould]

I had this problem, couldnt set the timimg because of my idle, I ended up taking it to Power engineering to get them to "dynamically" set it on the rolling road, made hell of a difference aswell (an extra 30bhp )

 

[geetee]

How do they set it 'dynamically'.

Presumably u read the manual and see how much advance there should be at a certain rpm and set it that rpm.

e.g.
Standard timing at idle on Optimax = 19 degs BTDC

Advance at 3.5K rpm = 15 degs

So run the engine at 3.5K and set the timing 4 degs BTDC


N.B. this is only an example cos I can't remember any figures. Pls don't go setting your timing at 4 degs BTDC at 3.5K

Cheers
GeeTee

 

[sypher]

when the engine rev's rise you have to advance the ignition timing as the time taken to create the spark by the colapse of the primary winding causing electromagnetic induction into the secondary winding is always the same however the engine is rotating faster, so to have the spark igniting the A F mixture/charge at the correct time in the cylinder the ecu must start the proccess of spark earlier in the cycle. eg idle 19' ----2500rpm =, 25+' all BTDC '' just example of advancement ''

could some on maybe do this,,,, with timing light on a GOOD car check advance at high idle eg;1200 RPM etc i cant as mines got no head

 

[geetee]

lol

cant as mines got no head

bit early to be worrying about ur timing surely! :lol:

I'm surprised it idles at all!

But not a bad idea.....

If someone with a 'normal' idling car could snap the timing marks at 300 rpm intervals upto 2000 rpm it would help a lot of ppl.

Of course this is no substitue to a. sorting out your idle probs b. getting ur mixture setup profressionally troughout the range.

Cheers
GeeTee 8)

 

[sypher]

Oh i'm not worrying cos i'm still waiting on bits, but still keep an eye on the posts to see if i can offer any assistance or just to learn from other peoples experiances especially as ign' timing SEEMS to be problematic

 

[jasegould]

How do they set it 'dynamically'

They set it on the rollers, definately didnt use any timimg lights etc....I imagine they advance it till it knocks then back it off a bit

 

[Websnowbo]

I imagine they advance it till it knocks then back it off a bit

Very technical of them.........

 

[tombola]

had another go at the timing today and goes as

i back the timing off fully by turining dizzy toward me
revs are 1100 ,check timing its reading -5 degrees b4tdc
as i turn dizzy away from me clockwise ,
i can get it to -10 b4tdc ok but as it approaches -15
the revs jump to 1500 rpm and the timing goes off the scale
about -25

it does this every time , i have the tps disconnected
and there is no fault codes
have just replaced the det sensor aswell

 

[jasegould]

quote="Jasegould"]Quote:
I imagine they advance it till it knocks then back it off a bit


Very technical of them.........

Well maybe a bit more to it than that but it definately worked, went from 240 to 280 bhp