Ignition Timing

[D16LJM]

My van (1.9 DG) has had a slight misfire at low revs, today I checked the timing with a timing light and it was slightly out, I adjusted (groove in pulley to engine case join) and it seems to rev clearer but does have a little pop from the exhaust when rolling to a stop which makes me think the timing is now out, all plugs leads etc look pretty new but thinking of ordering everything new so I know its not a plug or lead breaking down, what are your thought.

Pete

[Bubble Meister]

Separate the timing, the ignition and tuning.
Timing may give a slight misfire but not a popping (in my recent experience). It should be set to10btdc. Which notch on your pulley did you use? (Assuming it has two). Did you remove the vacuum hose off the distributor before setting the timing?

You can do simple checks on the ignition system: check spark gaps, check the coil has a healthy 12v supply, clean and inspect the 4 points inside the distributor cap, clean and inspect the distributor rotor. What state are the spark plugs in? Photo may help.

Tuning the mixture is more difficult without an analyser. But you can check the condition of the spark plugs (indicating mixture). Inspect all the vacuum hoses from the carb as these can cause niggly misfires.

Check the condition of tge exhaust. Any holes will cause popping on overrun.

Others may agree or disagree but the above is based on my own knowledge and experience of these engines.

(I'm currently chasing a slight misfire at around 2200 - 2500 rpm so have considered all the above).

[itchyfeet]

which timing mark did you align to case? there is a v shaped one and a u shaped one

do you have a gun with adjustable angle, made the mistake of not zeroing mine more than once.

[kevtherev]

Popping on the overrun is a classic air leak or weak idle mixture

[D16LJM]

I used the v shaped, didn't realise there was 2 marks, plugs all gapped correct and right colour, will have another look tomorrow after work as going brands hatch for the touring cars at the weekend.

pete

[ajsimmo]

Erratum:
Bubble Meister stated "It should be set to 10btdc"
This should read 5°btdc for a DG engine. (He may be confusing it with timing for a DJ).

[Bubble Meister]

Yep, good spot. It is 5 Deg btdc, not 10 as I'd originally stated.