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Model specific boards => Golf mk2 => Topic started by: Conker on 13 January 2008, 10:40

Title: Engine Timing Question
Post by: Conker on 13 January 2008, 10:40
Hi all, question regarding my 1991 16 valver...

I recently solved the misfire on my 16v'er by adjusting the timing using a timing gun and turning the distributor until the marks lined up. Last night I saw a picture on VWVortex that made me think something was wrong.

In the picture below, you can clearly see the timing marks. Unfortunately I have timed mine to the red X, not the 6 degree BTDC mark. The question is, it runs better timed at the red X shown below than at the 6 degree BTDC. What does this mean?  Does it mean my CO2 setting is well off or something like that? I.e. Im compensating for a weak/rich mixture by retarding/advancing the timing???

The odd thing is its now running 95% perfectly, apart from a slight stutter below 2000rpm when the engine is warm (its not there when cold). The other issue is that the distributor is FULLY turned anti-clockwise i.e. it can't go any further, and yet the engine seems to want to be turned even more that way to get it running 100% perfect.

Please help - I need to do a long journey in it on Tuesday and want to get this sorted ASAP.


(http://img29.picoodle.com/img/img29/4/1/13/f_Timingm_7f63d5d.jpg)
Title: Re: Engine Timing Question
Post by: saul79 on 13 January 2008, 10:42
it should be 6 degrees before tdc :smiley: with the middel off the rotor on the line on the dizzy. :smiley:
Title: Re: Engine Timing Question
Post by: Conker on 13 January 2008, 10:49
I know it should do, but it runs better when its more than 6 degrees BTDC ?!?!?!

Title: Re: Engine Timing Question
Post by: saul79 on 13 January 2008, 11:09
weird :smiley:
Title: Re: Engine Timing Question
Post by: Conker on 14 January 2008, 08:21
Anyone got any ideas??  I've got to fix it today   :undecided:

(I don't want to do a long journey tomorrow if its not 100%)
Title: Re: Engine Timing Question
Post by: Mew on 14 January 2008, 12:43
You're not using a timing gun with an adjustable advance are you?
Title: Re: Engine Timing Question
Post by: Conker on 14 January 2008, 13:18
You're not using a timing gun with an adjustable advance are you?

No, its just a boggo standard one, but cracking idea though Mew - that would be a perfect explanantion, as thats just what it feels like, i.e. its running reasonably well, but just at about 10 degrees BTDC, not 6 degrees.

Other very random ideas I've had...

1) The previous owner did something to it so that ran fine on 95 ron petrol, and since Im putting v-power in it its throwing out the timing?!

2) The static timing is out on the pulleys/crank?!

3) Its got a mild sports cam on it (don't think so)?!

Title: Re: Engine Timing Question
Post by: Mew on 14 January 2008, 13:22

Other very random ideas I've had...

2) The static timing is out on the pulleys/crank?!


That would be the first thing i would check  :wink:
Title: Re: Engine Timing Question
Post by: mk2mark on 14 January 2008, 18:16
10 degrees is not that excessive, as long as it starts ok and doesn't pink under load leave it as it is - wouldn't venture lower than the high octane stuff you're using though.
Title: Re: Engine Timing Question
Post by: dTEA on 14 January 2008, 20:28
10 degrees is not that excessive, as long as it starts ok and doesn't pink under load leave it as it is - wouldn't venture lower than the high octane stuff you're using though.

 :grin: mine loves Tesco's cheap sh1te!!!
Title: Re: Engine Timing Question
Post by: mk2mark on 14 January 2008, 21:07
The tescos stuff over there is quite good apparently!
Title: Re: Engine Timing Question
Post by: rubjonny on 15 January 2008, 17:59
indeed, on older/not clever ignition systems (e.g. k-jet, carb) using good fuel you can run more than the factory 6 degrees advance, which will increase the cars performance.  However try this on a Digifant 8v and you wont get far.  This is because the ECU automatically advances the ignition as far as possible, untill it detects knocking/pinking :)
Title: Re: Engine Timing Question
Post by: mk2mark on 15 January 2008, 22:45
Yeah was going to say I was wrong about that, read it in your tuning guide today!
Title: Re: Engine Timing Question
Post by: rubjonny on 16 January 2008, 08:14
wrong about what?  Everything you said was correct when talking about a 16v ;)