Misfiring

[jswagger]

Hi,

I have a 1988, 1.9 DG Auto that is misfiring and running roughly.

I had some new spark plugs lying around and fitted them with no change. The plug leads, whilst not new are in good condition. Van is starting fine, even from cold.

Anything to suggest to help?

Thanks in advance.

Jim

[Mocki]

Rotor arm and dissy cap ?

Also check for induction air leaks , a perished vac pipe end can cause all sorts of mis fires

[jswagger]

Cheers.

Can a failing or failed coil cause misfires?

[Mocki]

Yes, weak sparks

[itchyfeet]

does it do it when cold or when cold and hot?

if it's been left parked up it could just be damp, have you tried some wd40?

[jswagger]

Hi.

It misfires from cold, and still does it when engine has warmed up.

It's been misfiring for a few weeks but this is the first time I've had a chance to look it

Cheers

[jswagger]

Going to test the coil today to hopefully rule it out

If the engine is starting OK, does that mean the ignition amplifier is working?

[Mocki]

If the engine is starting OK, does that mean the ignition amplifier is working?

Yes, they either work or don’t , no maybes

[ajsimmo]

Just cured mine by changing the coil. Had a crack in the nose insulation and the spark was occasionally tracking along it to earth (found in the dark).
Also you may think your leads are good, but if you have metal shrouds on the plug ends they can cause problems, and can safely be removed.

Sent from my ONEPLUS A3003 using Tapatalk

[jswagger]

Cheers.

When testing the coil, should the ignition be on or it doesn't matter?

[DoubleOSeven]

https://www.championautoparts.com/Techn ... Wires.html" onclick="window.open(this.href);return false;

[jswagger]

Cheers, looks like I'll need an assistant then

[jswagger]

Hi,

Just an update, still not fixed.

The coil tests OK.
Can't see any vac leaks.
I've changed rotor arm, distributor cap, plugs and plug leads to rule them out.

Engines starts straightway when cold, but is a pig to start from hot, does this point to anything in particular?

Cheers again.

[Mocki]

You can’t "see" vac leaks , you can only hear them .....

[jswagger]

Cheers.

How can you hear any leaks over the noisy engine?