engine running rough series 2 convertible

[outage]

Engine removed and replaced all seals and clutch. Have driven about 50 miles since. On Wednesday, Tach went to zero and came back on a few minutes later...No issues with engine. On Thursday, while out, car started to run rough-sputtering, back fire but still running. Managed to get home and checked all connections at coil, distributor and plugs...nothing found. I had filled up car with gas at beginning of week and suspected maybe bad gas so added a solution to get rid of any water. Car has electronic ignition and appears to have not moved since engine replaced. I read a possible problem could be red cap inside distributor. I will remove tomorrow and see about a replacement. Any other solutions???
Plugs appeared black and sootty
regards Alan

[cactusman]

Red rotor arms are usually the good ones.....black and sooty plugs suggest an over rich mixture. Check the choke is not stuck on maybe?

[mgcjag]

Hi Alan......just to ad the red rotor arms from the Distributor Doctor are known to be good.....there are a lot of other red rotors available that are suspect copies.......this sort of problem can be difficult to find.....it sounds either electrical or fuel related....so check all connections...coils can brake down when hot.....distributor cap can be faulty..look at the center carbon that contacts the rotor.......fuel pump also a posibility look at the glass fuel bowl to ensure its full and you can hear it tick.....if yoy suspect bad fuel then drain if....never heard of an addative to get rid of water...where does it go ...Steve

[cactusman]

I'm with Steve....there is no substance you can add to magic the water away if you have fueled with contaminated fuel! Water and the alkane content of petroleum are immiscible....they won't mix. Water is more dense than fuel so will collect in the bottom of the tank where the pick up is. If your fuel contains ethanol...most does now...then I'd imagine that with sufficient sloshing at least some of the ethanol may wind up in the water but that is by the by.... If you have filled with water contaminated fuel you will need to drain off at least some of the liquid at the bottom of the tank....and avoid snake oil salesmen selling water removal additives

[outage]

pulled distributor rotor...showed absolutely no wear...ordered a lucas sport coil and will pick it up Monday...I hope this is the problem
regards Alan

[christopher storey]

The faulty rotor arms show no visible signs. What happens is that they become partially conductive when they get hot , because the plastic is an incorrect material. A test to check the arm is to place a thin sheet of plastic film between it and the centre shaft and see if it stops the trouble. If it does, it is your rotor which is the problem

[PeterCrespin]

I'm with Steve....there is no substance you can add to magic the water away if you have fueled with contaminated fuel!....and avoid snake oil salesmen selling water removal additives

Where’s Simon the Chemist when we need him? You must have been doodling E-types during orgasmic chemistry lessons Julian :-)

Several common alcohols dissolve/dissolve in water and also petrol. Obviously a single shot of vodka won’t fix fifteen gallons of heavily-contaminated fuel with a pint of immiscible water at the bottom. But ethanol/isopropyl alcohol and others will quite easily flush modest amounts of condensation or contamination through the fuel system whilst remaining flammable/combustible. No snake oil required.

[david muir]

Acetone's the stuff for combining water and organic solvents i.e. petrol. Lash a couple of litres into the tank and lo....... homogeneous liquid!

[christopher storey]

You must have been doodling E-types during orgasmic chemistry lessons Julian :-)

A Freudian slip ?? Orgasmic ( my emphasis ) chemistry lessons ???

[cactusman]

I know that. I was once a chemist. Ethanol is miscible with water and the contents of petrol. However adding water to an ethsnol/alkane mix in anything other than very small quantities will result in water containing some ethanol sinking to the bottom of the tank as a separate layer, as implied by the original post. Other than adding a large quantity of ethanol or similar alcohol there is little that can be done to remove the aqueous layer and there is nothing that can be added to "remove" the water ...i.e. Convert it in some way to something else

[PeterCrespin]

I know that. I was once a chemist. Ethanol is miscible with water and the contents of petrol. However adding water to an ethsnol/alkane mix in anything other than very small quantities will result in water containing some ethanol sinking to the bottom of the tank as a separate layer....there is nothing that can be added to "remove" the water ...i.e. Convert it in some way to something else..

If there's a bit of condensation or whatever, adding a fuel drying alcohol results in the petrol/alcohol/water forming a single phase mixture that is burned by the engine and thereby 'removed' from the tank. not 'converted' into another substance. Transubstantiation is best left to theologians.

It's all a question of semantics and proportion. Of course, if you go around adding water you'll get a puddle of it at the bottom as you describe, but there's no indication that happened here. Personally I am extremely skeptical of the bad petrol hypothesis anyway, especially as it ran rich, but adding a gasoline 'drying' product is a reasonable tactic in winter or after prolonged non-climate-controlled storage.

Pete

[outage]

I picked up new coil...lucas sport model , installed and no difference, fuel pump does tick, glass full, checked all leads/connections and appear ok. Will try the suggestion about rotor. Mine is blue and shows no signs of wear. I looked at distributor and appears ok with no wear. Will try wires tomorrow and then plugs.Grasping at straws-I took my ignition out of the circuit but no effect on rough engine. Do I do a compression test on engine ??? as maybe its a mechanical issue ; not electrical??
regards Alan

[outage]

It should have said"removed ignition kill switch circuit from coil" as grasping for straws.

[1954Etype]

Alan, have you taken the tachometer out of the ignition circuit? You said earlier on that all was well then the tachometer needle behaved erratically prior to running rough. There is a connector that goes from the back of the tachometer. Make sure that is connected properly and the contacts clean. If all is ok, unplug the tachometer and using a link, join the 2 white wires together. That will remove the tachometer from the system and enable the car to run. Note this is from memory so someone else might want to confirm what I have said.

[ralphr1780]

Alan, a ticking fuel pump does not necessarily imply fuel is properly delivered to the carbs.
I would double check that by unhooking the fuel feed line to the carbs (after the glass bowl), put it in a plastic bottle and turn ignition on to check the flow.

[AshM]

Correct Angus - plug has white in/out plus green. White connected across loom half of plug will remove the Tach. from Alan's circuit.

[1954Etype]

Thanks Ash!