RichieRoo

A new problem

After an hours drive, mostly queuing, the car started to falter at all engine revs.
If allowed to idle would stall.

On restarting the car will fire and if it's kept revving it will just about keep going
(although it misses every other second). This is no help to me as it's a tiptronic,
so I couldn't even think about dropping it into drive as the revs are raised.

I replaced the DME relay, both caps are new, dist belt is new, fitted new
distributor to coil leads recently. Car has been running fine.

There is a slight tick/click noise from around the rear fuse box/coil/ distributor
area - like it's arcing or a relay is clicking, which corresponds to the loss of power.

I'm panicking because it has to get me to work next week.

Your thoughts are more than welcome.

altarchsa

Sounds like spark plug wires have gone away. Look for arcing in the engine compartment and below in the dark to confirm.

elbeee964

re suggestion: A good start, (though encapsulation tins will prevent any reasonably quick access to the lower spark routes.)

altarchsa

You should be able to see the flashes of light evven if you can't see the exact location of the arc.

darth

Double check the work you performed recently, maybe something has came loose.

Bill

RichieRoo

Wow you guys are fast.

I've just been out to the garage and given everything a good check over.
I did check for arcing as you all suggest.

The top distributor cap (the one directly driven from the engine, not the belt
driven one) had lots of white arc marks on the central plastic connection,
where the rubber boot pushes on (See picture).

I did the classic test and ran the car on the other distributor and coil -
I couldn't believe it when it ran fine.

This pointed towards one of the new coils, so in the interests of completeness,
I physically swapped the coils over so that I was only using all the components
which I knew to be working. This recreated the problem and the
ticking/clicking returned (emanating from the coil).

BLOODY BOSCH "MADE IN BRAZIL" COILS! I concur with the all the other
posts... they do appear to be rubbish. This one appears to have failed
within 1000miles.

I hope to get it replaced tomorrow. I'll post again to confirm.

It's really good to know you chaps are there. Really appreciate it!

Rich

darth

I wouldn't suspect the coil to be the culprit but likely other components down the line, like the rotor, distributor cap, spark plug wires or spark plugs . From what I understand none of these components were renewed other than the caps when you did the coil wires and they're probably the same age and condition as the coil wires. All these components need to work in harmony, replacing just one or two components (i.e. coils, coil wires, caps) doesn't help much other than to put more stress on the weaker components if they're not "up to snuff". The photo of the distributor cap shows arcing at the input meaning the spark is finding it easier to go outside the distributor cap rather than the intended path thru the rotor, down the spark plug wires to the spark plugs. Check that the rotor and cap is in place and if they're OK I would look at replacing the spark plug wires and spark plugs then you'll never have to worry about them for another 100,000 miles or so. Also, the arcing on the distributor cap center electrode needs to be cleaned up, as rough surfaces like that only attracts the spark to take that route outside the cap and you want all the spark to be contained within the cap. The surface should be as smooth and shiny as the rest of the distributor cap.

Hope this helps
Bill

RichieRoo

Thanks for your reply Bill.

I agree with all your logic. Like you, I still don't see how something further up the line like the
coil could cause arcing lower down the line... but here's the thing:

I could reproduce the fault on either ignition circuit, just by swapping the 'bad' coil into it.

Just returned the coil to the shop and got a new one. Once fitted she runs fine again.
I hope this one lasts longer than 1000 miles.

Thanks again