Puzzled with really poor running Plus 2

[greg40green]

Evening Matt
your fuelling dilemma is very interesting , namely because I'm having exactly the same issues ie .
Bought my +2 pre COVID , then pandemic stopped play after very little use.
I drained the fuel off from the petrol tank and carbs due to not wanting the carbs to gum up and petrol to go stale.

Re-filled with 5 gallons of super unleaded 99 RON from a gerry can.
Started the car which smelled incredibly rich , took it for a short drive, some blue smoke which I accepted after the long stand , engine was miss firing , would not rev cleanly under load- when in gear and driving, but revved well when not under load - was not in gear .
I suspected carb issues , stripped and cleaned carbs numerous times but still ran incredibly rich sooting up plugs repeatedly each and every time .
Sent the carbs away to be ultrasonically cleaned , refitted carbs ran better but still incredibly rich , again sooting up the plugs requiring plug cleans and changes to re-start.
The engine would only run / idle on 4 cylinders for a short time then drop to 3 cylinders then 2 then would not start / run .
I suspected that the jets in carbs may have been drilled out prior my ownership , I changed all jets , still running rich sooting up plugs as above.

I fitted filter king to regulate fuel supply , no change , reverted to standard.
Fitted new fuel pump , no change.
Fitted new distributor , electronic ignition and coil , no change , still running incredibly rich .

After reading your information , I've come to the conclusion that the only consistent thing I'm doing is adding more 99 RON super unleaded fuel , with this in mind and the fact my low fuel light is on again , I'm going to add 5 gallons of standard unleaded fuel with no additives and see what happens .

I've also fitted 4 new COPPER CORE spark plugs which don't seem to soot up as quickly and start the engine better.
I'll update you regards what happens once the unleaded fuel without additives is added and the engine is run .

I've rewired my Plus 2 and am now trying to get her back on the road and I've experiencing some very odd symptoms. The car was running ok a couple of years ago when I started the rewire. I've got some type of electronic ignition (I assume pertronix) fitted in the distributor and I've got good feeds to the coil and distributor and good sparks at the plugs. The car is running(ish) on a pair of Dellorto DHLA 45s - the engine was tuned by Vegantune in the 1980s, petrol is new super unleaded Shell so no ethonal.
The car is a bit of a sod to start from cold, but using easy start type aerosol into the chokes it will fire up immediately. Once going it will restart easily but it will soot up all its plugs really quickly especially if the engine is under load - I'm getting through NGK B6ES types pretty quickly - and these are genuine items from a good source and are not internet fakes! Note that all four plugs seem to be sooting up at the same rate and the same amount
I suspect it is a carb issue, so checked the float heights - they were high so I've reset them back to where they should be, and resynced the carbs so they were in balance. The car was running ok on the drive and revving happily under no load, but going down the road the car missed badly on large throttle openings and I had to feather the throttle to get the engine to rev and pull - which it did on about 1/3 throttle. However very quickly the engine started to missfire and struggled to run and tick over. Getting the car back into my garage, I found that the brand new plugs were sooted up (again). The soot is very black and soft - plugs smelt of petrol.
A couple of other symptoms -
- This has been going on for a week or so, and on starting from being stood in the garage for a day after a previous days fiddling there is a fair bit of white smoke from the exhaust when the car first starts - I had assumed this was water vapour from the previous days fiddling about when the engine had been started, fiddled with, stopped, restarted etc. The while smoke disappears once the car was semi warmed up which sort of adds to the water vapour theory but may indicate I'm getting water into a cylinder (or two) from the cooling system when standing.
- after adjusting the float heights and rebalancing the carbs my colortune showed pretty much white (i.e. rich) on tick over but a healthy blue on revving (but of course this was not revving under load).
- there was initially a fair amount of blue smoke from the exhaust while trying to get the car down the road today, but it did reduce to virtually none by the time I got the car back into the garage; it did tend to do this before the rewire and I just assumed I had a bit of oil pooling in the head after running which was sucked in to the combustion chamber(s) and then burned off - when running 'normally' (or at least on the drive after staggering back) the exhaust was pretty much clear.
So, I'm thinking two (or three) scenarios in order of what I think is likely:
1. The sooting up of plugs is down to a fault in the carbs so the carbs need a good cleanout and service - but why both carbs and all four chokes are sooting up their plugs?
2. I've got a head problem which is pulling oil in to soot up all four plugs but again I'd expect one or two cylinders to be affected not all four.
3. Is the cylinder head failing and allowing some coolant to enter a cylinder?
4. Oil control rings are shot - but when I tested the compression I got an average of 190 psi (+/- 5 psi) on all four cylinders and again why are all four cylinders affected to the same degree?
I'm going to pull the carbs first and rebuild them with new seals, o rings, diaphragms etc - I did notice that no 4 cylinder's Auxilary Venturi was slightly loose which obviously isn't helping. Any other ideas from the collective?

[frogeyesimon]

Hi Matt.
The electronic ignition unit that I fitted to your car is a Powerspark (https://simonbbc.com/) unit.
It's been a while since you took ownership of the car from me. I don't recall having the poor running issues that you describe but it did used to soot the plugs up. I tended to avoid short runs for this reason.
For me, the best starting technique went like this.

(1) Crank the engine until the oil pressure registered.
(2) Very slowly push accelerator to floor 2 or 3 times and release.
(3) Crank the engine and it would fire.

I'm pretty sure that the above was suggested to me by someone on here.
Good luck. I always look in to your driveway when I pass your house. One day I will stop and say hello!

Simon

[rgh0]

The plugs should be BP6ES, not B6ES if they continue to foul due to your usage and carb settings you could try BP5ES

cheers
Rohan

[Mike Ostrov]

Rohan is absolutely correct with my Twin Cam experiences. The P is a projection plug, bringing the electrode and spark into the combustion chamber. If you could install both types of plugs, the B6ES electrode is hidden or sheltered. Same BP-x-ES plug is used on our Type 14 Climax Elites. The x heat range will be different. If I knew how to post a picture, would do so. Perhaps another can do it, please. Cheers. Mike.

[Matt Elan]

Thanks Rohan and Simon -
Rohan - I am using BP6ES plugs (and a set of BPR6ES which soot up just as much) so apologies for not being clear.
Simon - hows the frogeye going? The Plus 2 was running fine before the layup its what I've done to in in the meantime which is the problem. Feel free to drop in anytime and admire my new garage - coffee machine is on permanently and it would be good to touch base.
Regards
Matt

[Matt Elan]

Hi Greg
That is very interesting - I'm going to sort out some more fresh fuel tomorrow, so I'll try to find some 'standard' unleaded rather than super; it will be interesting to see if it makes any difference.
Regards
Matt

[Matt Elan]

Hello Mike - hope all is good with you and the Elites are running better than my Plus 2!
Regards
Matt

[draenog]

.

[Matt Elan]

Hi dreanog
I’ve not had the car running for long enough to have a chance to check the coil and coil voltage. But it’s a good steer as 90% of carburettor faults are electrical and vice versa. I’ll try to check when I run the sniff test tomorrow or Wednesday
Matt

[draenog]

Hi Matt,

No, I mentioned I had really bad problems with sooting up plugs caused by moving to super unleaded. Adjusting the carbs fixed it.

[Matt Elan]

Ah ok I’m getting new fuel tomorrow so I’ll try normal rather than super…..

[2cams70]

2cams70
May I ask please. About your reasoning for coolant draining before storage.

I would guess the reason for not draining coolant would be for anti-rust, and any flake making its way into the radiator or similar heater-core passageways and maybe blocking/obstructing.

I use a conditioner with my coolant, in hopes of lubricating.

Yes - even with coolant you risk corrosion happening if you don't drain it during long periods of storage. I'd drain the coolant if you plan on storing the vehicle more than a year. That includes removing the plug on the block. My experience is that if coolant circulation doesn't occur you can get localised pockets of corrosion happening. You see examples of this in areas where coolant circulation doesn't occur such as coolant trapped under hoses where they connect to outlets etc.

As to draenog's problem Lotus54 raised a very good point. If the wiring has been changed was the new harness checked to see if it incorporated a resistance wire? If not and the original one did and you are using a coil intended for use with a ballast resistor the coil will overheat.

[Matt Elan]

Quick update - I've serviced the carbs but have not found any issues - a little bit of dirt in the carbs, no blocked jets. I have fitted new float valves and reset the float heights again. otherwise all OK.
I've done a burn test on the fuel in the car, some new Shell 99 octane and sone 95 octane - simply by setting fire to a couple of cc's in a bowl. All three burned, all were pretty sooty and all three were pretty much the same.
So I've also drained the fuel tank and will add a couple of gallons of new E5 95 octane fuel. I'm kind of coming round to it being the fuel as its the same amount of sooting up across all four cylinders. I bought the fuel which was in the car in about September after ESSO started to add ethanol to its Super Unleaded so I'm wondering if this is the issue. Hopefully I'll fire he up again on Monday and will report back. If that doesn't work then I'll change the HT leads and coils, bearing in mind the 90/10% relationship of carb vs ignition issues.....

[mjbeanie]

I've a 71 Plus 2 that I've just restored and its running well. However I also have a 67 Sunbeam Alpine collecting soot on the plug near the firewall. The plug became so contaminated there was no gap it was closed completely.
It just looked like muck, at the end of the plug. It may be useful to post a photo of the plug for the group.

My car misfired very badly and I limped home on 3 remaining good cylinders, it was a rough ride. My sources tell me I've a head issue, worn valve guides, or control rings. (I will be pulling the head in the spring.)I would be interested to see what your plugs look like to get smarter your plus 2 issue as well. Keep us posted on the troubleshooting

[Matt Elan]

MJBeanie - Thanks for the input. My plugs are sooting up, all four the same. The soot is black, loose and soft and can be wiped off with a rag or soft wire brush or cleaned off with a spot of brake cleaner. It is not closing the gap per see, but obviously causing the plugs to short out. The engine won't run for more than a few minutes. Your issue is likely to be a mechanical problem with your no 4 cylinder as you've surmised.
Matt