Ignition Timing - D Jet - 1.7L (VW412)

Hello Dr-DJet,

First, I would like to thank you so much for your great information.

I own VW412 with DJet 1.7L. This car has continuously hard starting problem when it is cold. Most of all major parts related to Elec, Fuel have been replaced with new ones but the problem was there.

Finally, it was found by my VW air-cooled shop that if ignition timing is set BTDC 27 degrees at Idling, Not at 3500 rpm, the problem has completely gone.

Normally, I set that ignition timing at idling is about BTDC 10 degrees. However, from the above findings, it is set now BTDC 27 degrees at idling and everything is fine so far. (Very good Engine starting now)

Can you please advise me why BTDC 27 degrees at idling has solved the hard staring problem?

If you could advise me it would be highly appreciated.


Best Regards,

JH

Good Evening JH,

Please add some more details.
So do you have the vaccum canister connected during the mesuring?
Do you use a strobe light?
How many marks do your fan wheel have? Are you sure to use the correct mark, because in later years VW reduced the number of markings.
And the adjustment of the distributor also works correctly?

Best Regards,
Marc

Hello Marc,

Thank you for your advice !
I will post the additional information shortly.

BTW, Vacuum canister connection might be a cause of the hard starting problem ?
Why I am asking is that during the repair by the VW shop, they also found disconnection of the hose to the canister. 

Anyway please post the add information with some pictures.

Again thank you !!

JH  

Hello JH,

Yes, a disconnected hose to the canister will cause bad running, bad acceleration and so on.

Best Regards.
Marc

Hello Marc,

Regarding the ignition timing, I would like to send you some add information.

First, please see the attached picture "DJet IT2" which show timing mark on the fan wheel. This picture was taken when engine stopped. As you can see "I" mark with pink color paint on the wheel. The "I" is in the V cut part. I think the "I" means BTDC 27 deg. (Please remember there are two yellow lines paint on the right side of the "I")

Now please see the picture "DJet IT1". I used strobe light to measure Ignition timing at Idling speed. As you can see the two yellow line when the light ON. This means the ignition timing at Idling speed is nearly BTDC 27 deg. There is no other two yellow lines on the fan wheel.  

I have had Hard starting problem with Ignition timing BTDC 10deg. Now no hard staring problem with the timing BTDC 27deg.I was wondering if this is normal condition. As previously mentioned there is no Engine performance problem. 

If you could give me advice again it would be highly appreciated.

Best Regards,

JH

Hello JH,

yes, your pink I is at the same position as mine red one (sse picture below), it is 27°.
It is just before the broad footbridge.



Best Regards.
Marc