Can dirty fuel foul plugs?

It seems that every time I run my tanks low, the car fluffs and misfires. This morning (with low fuel level) I was running on 3 cylinders all the way to work.

Is there a way of unfouling a plug without removing? I have heard of pulling the plug lead off a bit while engine is running, to increase the spark jump. I have no tools and really don't want to drive home on 3 cylinders

It's eitehr a fouled plug, or blown head gasket. The car sat for 8 years not being driven.....so it may well be head gasket. DAMIT!

Will know later tonight I guess.....

Its fairly well documented that todays fuels are not good. A particular batch of fuel supplied by a company with red and yellow corporate imaging caused many cars here in Gulgong to foul plugs and misfire badly. The local mechanic was the first to realise the common link. This was a year back

My mini does not like anything but 98 RON and i now use BP and I havn't had a problem since.

My weber based race cars have sometimes wet a plug while its trying to start and once its wet its just keeps on fouling until its pretty heavily gunked up. Not even a good blast would clear it. But race cars run spark plugs that have a very different heat range to road cars.

My brother Kevin, when he first put in his hot 1310, it used to foul plugs and I had a feeling it was that it just wasn't "on cam" enough to keep them the plugs clear. Kev could tell you the outcome but he made quite some changes to the engine structure and i don't believe that problem still occurs.

Two situations:

1) to get you home today, start the car, take the lead off the plug you suspect is not working and see if the spark arcs to the plug by gradually slipping the lead back on. If all 4 leads are firing then it's the plug that's had it. To get it going again will mean taking the plug out and cleaning it up.

2) Long term:

I used to foul plugs ALL the time in the old engine running the dellorto. It usually was the outer 2 cylinders however I did foul 2 and 3 as well. It's a few things:

A) I always thought I just bought a dud plug. Probably not the case but once they do foul, they sometimes no longer work and need replacement
B) it could be an indication that you're running too rich.
C) it could be an indication that your rings or valve guides are worn and oil is seeping into the cylindr causing the cylinder to not fire due to contamination. It only takes 1 or 2 cycles to have "too much" fuel and oil in there for the cylinder to fire and hence a wet plug situation
D) plug leads/dissy cap/dissy points on the way out. In the new 1330 I was sure everything was ok but I still fouled a plug on number 3, or it just wasn't buring properly. I later found that it was the lead that was playing up, but my point is to check everything right up to the dissy
E) Heat range of the plugs you have now are too cold. Not efficient enough burn, lots of carbon or other deposits will prevent the plug from firing.

Considering that you currently have a problem with your weber (which either sounds like it is running out of fuel or is squirting too much fuel) I think that may be part of your problem.

I hate to say it but Dyno tuning is probably your only way of checking to see if your weber is running correctly and idling correctly. I reccomend Grieg Malure for that.

Sorry that I don't have a hard and fast solution but just know that it took me a new engine rebuild to fix my plug wetting problem...

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Lillee - 1969 Morris Mini K

Thanks Chong.

I suspect the cause is carb. The motor is in excellent condition, with NO oil consumption. I still think the Weber is pumping TOO MUCH fuel, and 'wetting' the plugs.

I agree about the dyno tune, but with my new job I can't take the car anywhere to get it done. I can't spare the time.

I just bought a cheap spark plug spanner. The best thing about my new job is that there is a Repco and Auto One RIGHT NEXT DOOR!

I will pull the plugs and check before going home today.

I am thinking about buying a single HS6 or HIF44, just to give me some daily driving reliability. I have a manifold, so only need carb.

I still to this day carry a spark plug spanner, a set of plugs, and a wire brush in the back regardless of what else, but fortunately my plug fouling days are over. It did coincide with the rebuild but the main change was a change to the heat rating of the plugs - I'd have to check when I get home, but I think they are BP6ES's.

For a long time, I carried a spare Lucas dizzy too, but that got tossed when the Pulsar dizzy went in!
KB

go for bp5es in winter/ bp6es in summer. worked for me

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real men race downhill - keiichi tsuchiya

yea i am running BP5ES plugs.....

Just out of curiosity , are they still the plugs that were in it when you got it or have you changed them ? What were the other plugs that came with the car again ?

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This is the third set of plugs in the car since I bought it.

1. The original (old) plugs. Still have them, but I think 2 were one type and 2 another type

2. The 'unknown' Bosch WR9LCX plugs. Ran OK with them, but they are apparently not Mini. Someone said FORD!

3. New NGK BP5ES plugs. Currently in it.

speaking of plugs there is a bosch one with teh number 7? in them I think I heard these were a better alternative to the NKG? Or something like that. I noticed the otehr week mine are 1/2 gone and need replacing as I've clean them and reset gap etc but still not the best.

I was fouling plugs on my S/C 1330 mini but not anymore. Just out of curiosty, I was recommended '7's currently I am running BP7ES's but my spare plugs, which I have used, are BP6ES 6 are colder than 7s right?

I knew colder for the car was necessary after my power increase, but yeah? What are other people running?

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1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T

BP5ES is hotter than BP6ES is hotter than BP7ES

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Lillee - 1969 Morris Mini K

Stale fuel is a prob over here as well.From Classic(old) cars to motorbikes.
I have now been using the Iridium spark plugs(IW20) and have not had a problem on first start-up.There not cheap though-appox $17.00 per plug

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IMHO, you have a Weber jetting problem. In 13 years running a Dellorto 45, I have NEVER ever wet a plug. And that's over 3 motors, the 1st of which (1310S) used to like a drink of oil too.
BTW that's running BP8ES, BP7ES, and Bosch W6DC plugs.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

yes Kev.....I agree with you.

I had a dead plug. Not fouled....just a dud NGK I believe. I won't be buying them again...so many issues with them in the last few years.

That got me back on 4 cylinders!

I still have missing issues. I adjusted the float height to the recommended measurement, and it now farts and coughts like a dirty dog.

Changed it back to what it was, and it's still farting around.

I give up.

When they run sweet I love them...when they run shite I hate them!

I am going to club plate this GT and buy a friggin Commondore!