Hesitation / misfire in bad rain

[Ashy]

Hi

Did a lot of miles over christmas period.

on the way back up the M1, after 3 hours of driving in torrential rain, holding 70 ish. had a few moments of hesitation or maybe misfiring.

Not had any problems like this before.

happened about 15 times, just a split second of hesitation and then back to normal.

Standard mk3 8v with drilled airbox.


anyone got any ideas  or suggestions please?

Thanks

[Screech16v]

Coil is a favourite maybe ecu relay 30

[tweed]

Relay 30?

It's a water problem. Wouldn't at all be surprised if water got in the dizzy.

[Screech16v]

Just because it was raining and this fault occured doesn't mean the fault is defo water related 

[AshyGTI]

First time I've really drive it in the rain.  Well monsoon conditions anyway.

Will have a look at those parts

Ta

[CJA321]

Id have a stab at the coil

[thai-wronghorse]

Coil, lead and plugs is where I'd start.

[javalin]

Worth checking the crank sensor wiring - its under the oil filter kinda area.  Common to see the insulation break down (aka fall apart) and then the rain/spray/puddle cause issues.

James

[thai-wronghorse]

Although from my experience of dodgy crank speed sensors is that the engine will cut out completely,  not misfire.

[Khare]

Although from my experience of dodgy crank speed sensors is that the engine will cut out completely,  not misfire.

From mine it can misfire. Insulation was all good, but the sensor bit that peeps inside the engine had a small crack in it. The only reason I knew it was the crank sensor was because it came up on vagcom as intermittent fault.