heavy rain and missfire

[bazpro]

went for a spin in my mr2 turbo the other night after we had all that rain and the car developed a missfire which let to it eventually dropping on to 3 cylinders for a few miles then back to 4 and working fine.
anyway thought it must be linked to the weather so checked the plugs.
pulled the first lead off under where the vent is and it was soaking and had water dripping out of it.
so dryed it off and cleaned it up, put it back together and the car has been fine since.
just wondered is this a common thing and is there anything i can do to prevent it.
i know the amount of rain we had up here was a bit of a one off though.

[RyanRs]

You defo have all the rain trays etc in place? Tbh I think mr2's are a bit sucky when it comes to real bad rain, I've had it once or twice back when i was on a dizzy setup and i also learned that you have to be careful when cleaning it with a jet washer!
Only thing i can really suggest is to check the condition of your leads + dizzy to make sure they are a snug fit.

[craig]

I had the same in mine yesterday, misfire under boost. Think it's the coilpack.

Seems common on MR2s.

[asdrewq]

OEM leads should not let any water into the plug wells. I would replace them if they are aftermarket or old.

Distributor cap 'o' ring in place?

[mr2turbo99]

Mine felt awful earlier this week after some heavy rain. It was boosting but not going anywhere. Took it for a long drive in the dry, really got some heat in there and its back to normal.

[bazpro]

one thing i did notice was the plug lead wasnt that hard to pull out as if there wasnt much of a seal.
the car will be in my garage most of the winter anyway its just ive been doing few jobs on it lately so its been outside my house for a few weeks

[p4uls]

I've had this problem on mine. The problem I found when it rains it drips onto the leads and after time the leads perish and hairline cracks appear and water gets past the seal into the plug crevice. Which in turn drops out a cylinder and then kicks back in when engine is hot and evaporates the water. the only solution was to buy new leads. hth

[rs007]

A good dod of silicone grease around the seals on the HT leads works wonders at not only helping prevent cracks in the rubber, but giving a barrier to water. Also makes them a wee bit easier to come out

[blue2]

Check the king lead that goes from the centre of the dizzy cap to the coil. This is a very common problem.

[bobhatton]

The coil is a big problem, as they are so old now they crack and when it rains it will give a miss fire or even stop the engine as it did with me on the outside lane once

[big_joe]

Have a look here

http://www.imoc.co.uk/forums/viewtopic. ... light=coil

[Jackson0]

Hi dear the coil is a big problem,, as they are so old now they crack and when it rains it will give a miss fire or even stop the engine as it did with me on the outside lane once......

[synXero]

Hi dear the coil is a big problem,, as they are so old now they crack and when it rains it will give a miss fire or even stop the engine as it did with me on the outside lane once......

Bob, you have an adoring fan!

[bobhatton]

I could do with one at my age

[rgb]

mine used to do this and it was the big plug underneath the fuse box . you had to squeeze your hand in to reach it. not a very good answer but when your sat broken down in the rain its worth a try

[Ryan S]

Glad to see I'm not the only one with this problem!!! Less rain tonight, car's been fine!!

[Marf]

My car hasn't started for the past 2 days due to the rain

Need to get a new coil on there I reckon. I can't even remember which leads my Rev3 has, 5mm or 7mm?

[Baker]

5mm

[leary123]

mine ran god awful for 2-3 days.. major idle problems and hated boost. checked everywhere for air leaks round the engine bay.. couldnt find any. got new leads, dizzy cap. checked them all over. checked each cylinder was sparking with a spare plug... all good... in the end, the sodding vacum hose had come off the boost gauge in the car