[Spitfire Engine coolant drain tap]

But what sealer to use in addition to the copper washer?

[Spitfire Engine coolant drain tap]

26 minutes ago, NonMember said:

I think it's a copper washer but it's a while since I changed one.

Check the thread is clean and of full depth - if it's obstructed by rusty crud at the bottom (which is highly likely) then the new tap won't screw far enough in to seal properly.

So no additional sealant of any sort with the copper washer?

[Spitfire Engine coolant drain tap]

Hi all,

My spitfire MK3 brass coolant drainage tap leaks from where it is screwed into the block. The tap itself is knackered, with lever snapped. Got a new one and so far have tried to fit, but it leaks every time ? I first used PTFE tape on the thread, then after that failed I used plumbers jointing compound, that failed to seal and then a fibre washer followed by a rubber washer………..still leaks coolant where  it meets the engine block. Do I need a copper washer or something else?

thanks Mike 

 

[Spitfire Mark 3 - misfire]

I always start my spit and let it get to temperature before heading off. The choke I gradually push home after 15-30 seconds.......of course every car is different with its own temperament LOL.

Mk3 spits always run rich at idle, even when using a colourtune kit, you have to run it at different RPM's to adjust jets. but you're saying that after warm up the plugs are sooted up? Mine always are after warm up before I head off, only after I have a run do they go a slight charcoal/brown and all that soot is burnt off....................................what if its the same problem I experienced lately see my post 'Spitfire mk3 - spitting'.

 

Mike

[Spitfire MK3........spitting!!!]

Finally!!

Thought Id check in and let you guys know the problem. I swapped the the coil with  a known coil that works, the problem still persists.............................................

BUT, when replacing with my original coil, I noticed that there was a frayed bare wire protruding through the wiring loom that goes to/from the solenoid. This bare frayed wire was touching the bulkhead panel to which both the solenoid and coil are fixed to. (see pic) I part stripped the loom to expose the wire (which wasn't connected to anything) and decided to cut it cleanly and used a combination of liquid electrical tape and electrical insulating tape at its termination point. I can only think that this cable could of fed some accessory at some point and was abandoned. Everything put back together and fired the car up - BINGO, no misfire, no backfire.....in fact it ticked over nicely and even at 900rpm. I checked that all was firing nicely with Accuspark plug check and they all ran evenly like a Xmas tree (see pic).Took it for a spin and it goes like a rocket!!!.....no hesitation just nicely and strongly. Going to drive it around for a while as i missed the summer and check the mixture before putting it to bed for winter.

Id like to thank everybody and their suggestions to help solve my dilemma, which now is solved.

Many thanks Mike

[Spitfire MK3........spitting!!!]

13 minutes ago, alan.gilbert_6384 said:

Adding a two penny worth, have you got a colour tune spark plug ? Worth checking Mixture as a sooty plug is a rich mixture and best way to set it is with a colour tune in my experience ( the other ways are not as reliable ) and you can see what happens as you rev the engine and at all speeds as you gradually increase the range. You can also see if your burning oil in the mixture.  Failing that just change the plugs first and see what happens, good luck.

Yes I have a colourtune and used it once or twice but unless you have perfect carburettors it is quite erratic in producing accurate results

[Spitfire MK3........spitting!!!]

4 minutes ago, Pete Lewis said:

you  have to check your timing to rule that out 

and to correct flat spot acceleration use engine oil in the dashpots 

pete

 

Yes timing good. And I have engine oil in the dash pots 👍

[Spitfire MK3........spitting!!!]

17 minutes ago, DanMi said:

sounds like stale fuel to me or at least those are very similar to the symptoms that my car had after lockdown, and is any easy fix (well not at the moment!)

To be honest what you’re say is an easy fix, I could drain the fuel and use it in lawnmower…….then just try and get hold of fresh fuel 🤔

[Spitfire MK3........spitting!!!]

No I haven’t yet……..especially with all the petrol pump faff going on. 
After I’m happy that the ignition element is in order I’ll move to check over for air leaks and then fuel. I replaced the fuel filter. 
The thing is, it starts and runs/ticks over lovely, when I gradually depress the accelerator all the way to around 4000rpm no misfires only happens when I blip the accelerator erratically. Driving out of my driveway and up the road under acceleration it pops, misfires and holds back, as if someone is depressing the brake!!! 
hopefully in the next few days I can start eliminating possible causes.

mike

[Spitfire MK3........spitting!!!]

7 hours ago, Paul H said:

Have you checked the Powerspark , same as Accuspark unit . Check the magnet is not too close to the electronic unit and the bottom of the rotor arm is not clipping the electronic unit . A giveaway is black dust particles when you remove the dissy cap . Lastly check the rotor arm has no fractures 

Paul

Paul all checked and fine mate

[Spitfire MK3........spitting!!!]

30 minutes ago, chrishawley said:

Of the number of times I've offered the benefit of my advice about this sort of problem at a distance I've been wrong 50% of the time. But here goes anyway!

My guess would be that the issue is on the ignition side rather than carburation or internal condition of engine. Or, to be more precise, it's aspect I'd investigate first.

Assuming one still has the original distributor a way to proceed would be to substitute the Powerspark unit with the original one with its own points, condensor, cap and leads (such as are to hand and in fair condition) and leave the vacuum blanked off at both ends. Outcome will be a) improved = diagnosis is the Powerspark unit, b) No change = diagnosis is not the PS unit, c) worse/differently worse  = no useful info.

And of course, swapping between points and EI and vice verse necessitates re-timing.

If 'a' that would be no surprise to me because I've had two EI units fail in under 100 miles: One because it was spiked off a superboost battery charger and one because it just failed.

If 'b' then i) multimeter check that with engine running there is a 'clean and stable' 12v to coil (I'm assuming your system is unballasted). If suspect, coil can be hot-wired off the battery for further checks) ii) check coil for approx 3 ohms across primary winding (if 1.5 ohms it's the wrong coil) and between primary and secondary windings many megaohms (varies by coil but lets say 10).

Another exploratory investigation is to get a new, correctly gapped, sparkplug and connect directly to coil and touch down to engine block. Cranking should then give a good spark at twice engine rpm. Repeat with each plug lead which should then give spark at half engine rpm. Rather hard to describe what a 'good' spark looks like compared to a 'feeble' one so that's a matter of judgement. But any variance between the 'coil' spark and the 'individual plug' spark narrows down the area of enquiry a bit.

Without trying to cover everything in one post some other experiences I've had with this sort of thing are.

• Triumphs: Air leaks in breather pipes, no oil in dashpots, air leaks at inlet manifold, wrong needles or jets

• Mini: Unpredictable misfire: Compression test seemed reasonable(ish) (15% variation) but valves, guides, seats all severely deteriorated

• VW T2; Misfire, poor pick up. On strobe timing could be seen to be 'dancing' and flitting around all over the place. Extreme wear in distributor drive gear and distributor shaft.

I have the premonition that everything I've mentioned above is wrong (!) but I hope it might stimulate some thoughts about how best you can proceed with further investigation.

 

 

Very useful and interesting information  there, many thanks. The testing of the coil looks complicated to me, so I’m waiting for my mate to pop over so I can take his coil off and substitute it with mine to see if that is at fault.

I did initially start the car with a boost from the battery charger…….so interesting to see if that cooked the EI module in the distributor. 
The timing is spot on ………..I have checked dozens of times now as it’s got to a point where I keep doubting myself now LOL!!!

I think I’ll then proceed to replace spark plugs, ignition leads (copper-less core as recommended using with EI)……………then finally the module. I replaced the distributor because the original one had so much play in it………so that’s why I opted for the EI. As I mentioned before I had it all set up beautifully and did a 1200 mile round trip faultlessly, left it a few months and then the problems began!

If the problem still persists after replacing all electrical bits above, I’ll move onto to possible air leaks as suggested above……………classic cars- don’t you just love them 

 

[Spitfire MK3........spitting!!!]

10 minutes ago, clive said:

Not sure if you have posted this elsewhere, as I replied to an almost identical post earlier...

anyway, yesterday I helped a mate who had a misfire on his stag. New lucas coil, bit better but still happening. Fitted an electrnic ignition module, no change. Checked fuel system, new filter etc, still there. I suggested trying my (27 year old) lucas coil. Instant fix. The new one was poorly made and getting VERY hot. Easy fix, but people assume new parts work, e=when the reality is many are poor quality.

Likewise the "new" distributers. The only one I have come across was so bad out of the box (would not rev above 3k) the original was refitted. Not sure what happened as that was before covid, and not seen the chap since. 

Thanks for that Clive, I have only posted this thread. Yes, I believe you may have a point re new parts and quality, I do have an old coil, so I may dig that out and try with that. The distributer I bought and fitted 2019 together with a new coil.

..................now where did I put it? Mike

[Spitfire MK3........spitting!!!]

Thanks for all the advice above.

I did the compression again with butterflies open and got readings 135, 137, 137, 115 starting from the radiator end (front of engine, so marginal differences in reading. I am waiting till Monday to contact www.simonbbc.com who are Powerspark Ignition in Bromsgrove to see if there are issues with the module etc. Although i have read that Powerspark do recommend using non copper cored HT leads, but I think this is more for better performance as opposed to developing faults. Spark plugs are Champion N9YC.

I cant find anywhere whether the ignition timing needs to be altered if electronic ignition is fitted, again i will seek guidance from them.

The carbs are set up perfectly I believe. The car starts without problems and once at operating temperature it idles without any misfiring. When increasing revs gradually to 3-4000rpm there is no misfire, only a misfire occurs from idle if I blip the accelerator rapidly and sharply. Also there is faint white smoke puffing through the front carburetor when there is a misfire after I blip the accelerator pedal rapidly on and off.

Mike

[Spitfire MK3........spitting!!!]

Pete,

I will contact Power Spark and ask their advice.

Don't have Waxstat luckily!!

I note your point about throttle closing re compression test.

All things to look into.

Again thanks

Mike

[Spitfire MK3........spitting!!!]

59 minutes ago, Pete Lewis said:

back fire and misfires is looking towards condenser  but you have an electronic dizzy   ...who's unit is it

most electronics do not need a condenser  but>>>>>>if it has  

if it has a orange wire be suspect 

suggest you buy one from    http://www.distributordoctor.com/distributor_condensers.htm

do you have spark plugs with an R in its suffix       note there s a post about all the comments on these  but i find they are troublesome 

stick to straight BP6ES      not  BPR   if  you have NGKs 

on you compression test  did   you have the throttles  OPEN  ???

Pete

 

Pete,

Finally found it.......Powerspark Delco type Electronic Distributor.

I think ill check all connections at coil as well and get in touch with Powerspark Ignition and see if there have been any known problems with these.

Mike

[Spitfire MK3........spitting!!!]

14 minutes ago, NonMember said:

To get the most representative and consistent compression measurements, you want to minimise any restriction to getting air in, hence you do the test as you describe but with the accelerator on the floor - throttles wide open. I don't usually find it makes very much difference but that's the "book" method.

Ahh right.........thanks for that.......gotta be done right!

Will try again tomorrow

[Spitfire MK3........spitting!!!]

Pete, I cant remember who's unit it was......trying to find some paperwork. there are no markings on the actual distributor to identify it, will look tomorrow.

The distributor has a vacuum take off and mechanical tachometer but with electronic bits inside replacing the condenser and points.

I note your comments re spark plugs and will check these.

Not sure I understand "throttles open" ? On doing the test, I removed all spark plugs and connected the gauge to each cylinder and allowed 5/6 turns of the engine.

Thanks 

Mike

 

[Spitfire MK3........spitting!!!]

Hi everyone. I have been a member of the TSSC for about seven years but never used the forum as I have pretty much managed to solve problems that have ever crept up with my Spitfire. I am the second owner of the Spitfire. After restoring it six years ago, I took my partner on a road trip doing the N500 route in Scotland and returning home to Kent via the Lake District - very satisfied at an achievement. The car didn't miss a beat!! Mechanically, the car was sound, engine, gearbox, axle etc etc. The carburetors were overhauled and distributor replaced with an electronic distributor with mechanical tachometer. There was always a minor back fire at high revs, but apart from that it was sound. The car was in the garage for six months since the trip and last week I decided to start it and take it for a run. I always start it and let it warm up to operating temperature then off I went. It misfired on (attempted) acceleration and was a real pig..................it sounded rough as old boots. Back to my garage tools were out, timing checked, carbs checked (adjusted and re balanced). On revving the engine at my garage, a backfire would blow through the rear carburetor and the engine feels like its holding back?. I even did a compression test which more or less matched my original figures when I first tuned it all those many years ago. Readings were Cylinder 1-135, 2-135, 3-145, 4-110 psi. I always had a slight suspicion at cylinder 4 because of a minor oil weep at the back of the cylinder head and engine block mating surfaces - head gasket?. My question is  - that with the same compression readings before (when all was well - apart from minor back fire) and now after, it must point to something else. Granted the head gasket maybe gone and the trip progressed that - but there is no oil in the water/radiator? Regarding the carburetors, I only overhauled them using Rimmer Bros kit. Somebody suggested that the carburetor connecting rod bushes may need doing as its impossible to tune the carburetors correctly........this, perhaps could be true as there is some lateral play in the connecting rod? Checking the plugs they all appear sooty - rich mixture, in turn minor lifting of the carburetor piston, the idle remains the same for both carburetors - I assume this is correct?.

I want to avoid taking the head off (although I can see this might have to be done to replace the head gasket and check valves) making sure I have covered all other avenues first. I wonder if there is an experienced classic car tuner in the Kent area that I could contact re tuning the carburetors?

Any way, any advise or comments would be very helpful in trying to solve the issue.

Thanking you all in advance