Getting OGU roadworthy again

[billwill]

I booked in for an MOT test on Monday morning (tomorrow) and on Saturday was clearing out the tools & accumulated rubbish from the passenger space, when I realised that I had not actually tested the brake lights. Tricky to do on one's own.

So I used a broom handle to push the brake pedal and had closed the garage door so that I could see the red glow. To my horror the brake lights were not working, but it was too late on Saturday to do much.

So up bright & early today. Visions of a dead brake pressure switch, not obtainable in an instant; thoughts of how I could rig a mechanical switch on the brake pedal from bits & pieces around.

Ran it up on ramps balanced a long mirror against some bricks behind the car so that I could see the brake lights from under the car & crawled underneath with a multi-meter, pulled the wires off the brake pressure switch & checked; there was 12v to chassis on one of the wires, good ho.

Made up a short wire with two spade connectors to join the disconnected wires, in place of the pressure switch. No brake lights on at first, but shortly after due to a bit of wiggling of the wire, I could see that they came on... Hooray... diagnosis = dirty contacts on the switch and its connectors.

So brass wire brush & a bit of sandpaper & a pliers to squeeze the slide on connectors a bit tighter.

But could the brake pressure switch be broken also as an open circuit? .. Moved the mirror to approx 45 degree angle so that I can see the lights while pressing the brake pedal with my foot. ... Bingo all working fine.

Ready for MOT test tomorrow.

[AHM]

Sigh of relief!

It is going to be a nice day tomorrow too!

[billwill]

Pictures worth a thousand words.

Elan at Trotters Bottom, June 2013

Elan Tax Disc, June 2013

[billwill]

I think I should fill in a few details of what preceded those photos above.
I had already arranged that my insurance was uprated from off-road to on-road before the end of May; though they charged for the whole year, not pro-rata for the months remaining of the current contract, which was slightly annoying..

Anyway, after that last bit of fixing of the brake light switch on 2nd June, I took it to my favourite MOT garage, via a long route that included a quiet road next to the allotments, where I could check the brakes a few times

Safety rules must have tightened up, for MOT tests since last time, since they used to prefer that I drove it onto the 4 post lift and stayed inside to activate the lights horns & steering etc, THis time it had to be Andy one of their chief mechanics, so with some trepidation I watched as guided by a colleague he drove it onto the 4 poster, with me wondering if he was familiar with strong clutches and rubber doughnut transmission and a wheel span that was only just on the plates. He did fine.

Anyway being off the car this time gave me the chance to ensure that he used nice thick wooden beams across all three pipes of the rear swinging arms when he lifted the wheels.

So she passed the MOT test fine anyway in the morning of 3rd June.

~~~~
So being totally law abiding I next had to arrange for a tax disc, well also since UK police now have powers to confiscate and CRUSH cars that are not properly insured and 'taxed', there is no point whatsoever of taking the risk of running afoul of a jobs-worth PC Plod.

So I got on-line to DVLA at lunch-time and after trying two useless reference numbers from older V5C Registration Documents, I finally found the envelope in my papers file, in which the latest red V5C was hiding { for those who don't know, there was a theft at the DVLA of a lot of blank blue V5C document sheets, so to foil potential fraudulent use of them, the DVLA issued everybody with brand new V5C documents with red printing instead of blue and each with new reference numbers.}

So I entered all the right stuff on-line and encountered a screen where it asked if I wanted the new tax disk to start on 1st JUNE, or 1st July. Naturally I wanna drive it NOW so there is no doubt that I put the dot in the 1st JUNE selector. The rest proceeded normally and as it is a pre 1974 Historic vehicle, that actual tax fee is zero pounds. Pleased was I, so I started to print the confirmation page to carry in the car until the actual disc arrived in the post, when to my horror I saw that the confirmation page said that the disk would run from 1st JULY

Aaaargh! I was dead sure that I had ticked the right box, so it must be a pesky error on the DVLA website. There was no facility for fixing this on the website, so I found the phone number and called the DVLA. The agent that I spoke to there was sympathetic but he said that the database showed that it was due to start on 1st JULY and clearly he did not believe me when I said that I had definitely selected 1st June. Clearly he has not had as much experience of how computer programs are often wrong as I have, (it was my trade though I'm now mostly retired). It did not appear that he could fix it there, but he suggested a workaround, that I could take my V5C, Insurance & MOT certificate to a local Post Office and get a tax disc over the counter.

Grumbling to myself about sloppy website programmers, fully expecting that the Post Office procedures would also be on-line to DVLA & therefore reject my request, I made my way (by bus) to the Post Office. As always there was a big long queue shuffling along. Finally I got to the front of the queue and to a counter... The clerk points out that he is just about to take a break, would I please go to a different counter.. "But", I said, "At this moment all I want is a blank form to fill in for a tax disc!". There are no such forms says the clerk. My spirits drop! after a short discussion I realise that what he is saying is that I just need to show the documents to him and he does the rest on his computer terminal.. My spirits rise again..

All this appears to have intrigued the clerk & he forgot about his break and processed the documents for me and we have a bit of friendly discussion about historic cars and how they get free tax discs. So I don't have to do any money things and I get a handwritten tax disc and a till receipt that says ?0.00.

I hot foot it out of the post office before the dumb computer systems catch on to the face that I will now get two overlapping tax discs..

Bus back to my house, insert tax disc in windscreen holder and off I go, finally fully legal on the road out to Trotters Bottom to take the photos shown above.

~~~~~~~~

A few days later, the second tax disc arrives by post from DVLA and guess what.. it runs from 1st JUNE 2013 to 31st MAY 2014.... Computers ! Love 'em or Hate 'em.

[richardcox_lotus]

Well done Bill - glad you are back on the road.

The interesting thing will be whether you get 2x tax reminders next year !!

[billwill]

Well as part of that first run on which I took those photos, I did notice that the engine was still a bit rough. Not surprising as I had not attempted anything other than a cursory tune up, as I could not load the engine.

Anyway as I was out there north of Barnet, I went over to See Rob Morley in Potters Bar (my engine man who had built up the new head for me. http://www.pro-tune.com/), basically just to show him that it was on the road again. I mentioned that it was still running a bit rough and Rob took time out of an engine installation that they were doing, to have a fiddle with the carbs. After a while he said that the settings on Cyl4 didn't seem to have any effect and it wasn't firing properly so I should check the sparks and if they were ok, clean out the rear carb. Oh and GET FRESH FUEL... and try some EP 6 spark plugs so that they were less likely to coke up.

Well I had done a carb refurb, but that was 3 years ago and my car had been immobile since, with the carbs in a box, so they could easily have crudded up. I checked the sparks & they were OK, but before actually taking the carbs off again, I took off the top of the rear Dellorto and taking each jet & emulsion tube out I blew compressed air through the channels (at first forgetting to soak all the fuel out & so getting an almighty spray of petrol everywhere ... & there feeling an idiot!)

The air was the last dregs of compressed air from my sub-aqua diving tanks, last used underwater way back in 1993. They are completely empty now.

The only thing I found that could be wrong was that the cold-start jet had fallen out of its emulsion tube and by the time I got it out of its deep recess it was indeed crudded up. I cleaned that out and fitted it properly; though I could not imagine it was relevant as the 'choke' was not being used during the rough running.

Anyway I consulted the "Tuning Webers & Dellortos" book and realised something new to me, i.e that Dellortos have a bypass setting screw to balance both throats of a dual carb and if they were not set (i.e. if I had fiddled with them during the carb refurb) that would explain the inability to set the idle mixture. So I checked and the bypass screws were pretty much closed so probably not an issue.

Well I tried setting up and balancing the carbs once more by trying the listen to each carb trumpet via a plastic pipe technique and I thought I had got it set pretty good, though it is difficult as the bypass screws change the nature of the sound from a burble to a hiss. Then I went out for another run. It was slightly better, but still a bit rough. It really is difficult to set that middle screw that adjusts the relative throttles of the two carbs.

So I examined my wallet, groaned and then via the Internet, I bought one of these.:

Synchrometer

Synchrometer.JPG (76.55 KiB) Viewed 2171 times

http://www.ebay.co.uk/itm/Aldon-Automot ... 53fa728dfa

It arrived the next day, but I had other things to do (and it was raining) so it wasn't until Sunday last week 16th June, that I got chance to try out the syncrometer (and it was still doing rain showers ). Anyway it was a dream technique with the meter, it was so easy to check each trumpet of each carb and first get each carb balanced with the Dellorto bypass screws and then finally get the two carbs matched to each other by setting the centre adjuster. I knew the idle mixtures themselves were still not right but I went for another brief run and it was much better.

On Tuesday, I got a set of copper cored EP6 spark plugs from Halfords, then on Wednesday 19th I cleaned my Colortune plug and carefully set each idle mixture to be a bit on the lean side (only occasional orange flashes) and inserted the new EP6 spark plugs instead of the sooty EP7s

Then I went out for another run, including my favourite Trotters Bottom Lane (c.f. Emma Peel) and it seemed damn near perfect, just like I remembered her running before the head crack misfortunes. Just a bit of exhaust popping when you get back into congested streets after a quickish clear run. As I'm running in the new head, I wasn't going very fast in any case.

So finally I think she is purrfect and I put her back to bed in her cosy nest, as I had other mundane things to do like drinking beer with friends and making a much delayed start on cleaning up my front garden.

[billwill]

Well after all that I couldn't resist taking her out again 2 days ago and to share the joy with all of you I charged up my camcorder and rigged a tripod on the passengers seat, strapped to the seat supports and I videoed a run of about an hour and a half, out to Barnet and around the lanes.

You would get bored with the whole thing, so I edited a film of the best 8 minutes or so and I have uploaded it to Youtube for you all to enjoy.

For best enjoyment ensure that your computer sound is turned on and the volume is set as high as practical.

http://www.youtube.com/watch?v=WOOuUKQrmbE

Enjoy

[richardcox_lotus]

Good to see you back on the road. I noticed some things on this video:

1) your bonnet is lifting - about 1:30 in
2) my wipers are parked on the wrong side compared to yours
3) I wished I lived there as the roads have a lot less potholes than mine do.
4) engine sounds good - those STE meters are great. Takes a lot of the guesswork out of it.

Regards
R

[billwill]

Good to see you back on the road. I noticed some things on this video:

1) your bonnet is lifting - about 1:30 in
2) my wipers are parked on the wrong side compared to yours
3) I wished I lived there as the roads have a lot less potholes than mine do.
4) engine sounds good - those STE meters are great. Takes a lot of the guesswork out of it.

Regards
R

Yes, but I have non-standard bonnet fastening, which you can't quite see on this piece of the video, The two pull cables on the dash are no longer there, instead there is a barrel-lock on the bonnet top near the centre of the windscreen, which rotates a long steel tongue into a metal reinforced slot in the body. So it is in no danger of flying off. The slot is a bit wider than the tongue is thick so it does lift a bit. Sometime I will put a rubber sleeve on it to minimise the lift. My previous sleeve has worn out due to the frequency that I've had the bonnet off during the rebuild.

{you can see the re-inforced slot in the pictures of my engine bay on this topic: lotus-twincam-f39/clay-test-checking-clearance-between-valves-pistons-t26441.html?hilit=clay%20test}


My wipers don't self park anymore, basically because I have not yet been able to get one of the proper electrical connectors to plug into the replacement wiper motor. I have to judge when to stop them so I usually park them on the passengers side as it is difficult to judge exactly when they are fully down on the drivers side.

[billwill]

Ah, not quite right yet.

I went out for a spin today and after about 5 mins at 3000 Rpm 60 MPH on the A1(M) the engine started hesitating a bit and then after coming off the motorway I found that brisk acceleration around the 2500 RPM mark was a series of surges instead of smooth, which coupled with the flexibility of the doughnut transmission, made it fairly uncomfortable. So I came back home vis a non-motorway route at typically 40mph. A brisk sustained acceleration seemed to make the symptoms go away for a while, but they came back.

Finally these symptoms were not evident during the last few miles in town traffic.

Anyone got any ideas where I should look to explain/cure this?

[richardcox_lotus]

Initial thoughts would be:

1) crap in fuel making its way through the system
2) advance curve ??

Regards
R

[billwill]

Hmm, crap in the fuel is supposed to be trapped by a filter in the pressure regulator that I have (to cope with an electric fuel pump), so should not really be an issue, but I must admit it fits the symptoms. Possible blockage of the progression holes?

The next likely thing seems the accelleration pumps, if they are not balanced or are sticking in their tubes when warm it could be jetting fuel in pulses. Doesn't quite cover the case of hesitation during the steady 60 mph run though.

I had not contemplated the advance curve issue, As I thought I had checked that the distributor was working as expected.. Well as far as can be judged without expert tools. However, sticking of the advance weights could cause such symptoms, I think.

Anyone else any thoughts, or seen these symptoms before?

[billwill]

After considering Richard's thought about the Advance Curve, above, I realised that in fact I had not actually checked the ignition timing anyway, because my timing light broke long ago. I had merely set an initial static figure and then jiggled it by ear to what I thought was a good setting.

So on Wednesday, I ordered a new strobe timing light from Draper, after checking that the one Alex bought last year was no longer available. tool-talk-f43/timing-lights-t27111.html

~~~~~

My Draper Timing light arrived today; it works fine just as expected and the light is bright enough for me to see the timing with the nose of my Elan in the shade in my garage and its tail (and exhaust fumes) outside in the bright sunlight.

Not relating to the instrument itself, but my radiator is pretty close to the front of the engine and I could not see the pulley well enough, so I had to unbolt the radiator and tilt it forward. This of course required temporarily fitting a longer top radiator tube, a nuisance but no option really.

Miles Wilkins' book has a rather bewildering amount of information on advance curves and my engine has been modified so many times and now with a brand new SAS head specified as similar to Big Valve or Sprint, and with fuel octane ratings lower than originally expected for Elans, I'm not really sure what advance curve I should be using in any case. So I decided to check for Miles Wilkins' Big Valve curve which is 12 degrees up to 2000 RMP then rising to about 26 degrees at 5000 RPM and stating at that for higher RPM.

So using the light I checked my existing setting and found that it was about 20 degrees at 1000RPM... rather too far advanced and it rose to near 30 degrees at faster RPM. Ooop!. So that could account for my hesitation at 3000RPM, 60mph on the road last Saturday.

So I loosened ant rotated the distributor to be a more sensible 12 degrees at 1000 RPM and this caused the idling speed to drop drastically (is that normal ?? ), so I had to screw in the idling speed screw to get it back to 1000rpm.

Then on revving the engine I noted that the corresponding advance would only go up to about 20 degrees max, not the 26-29 that I was expecting, so that points to problems with the centrifugal weights. Or that the distributor was tuned to that strange curve on a previous build. Anyway the engine was too hot then (I 'scalded' my arm on the radiator) to consider taking the distie out to check & oil it. Also I must check with Rob Morley, what curve he recommends now for this engine and whether or not he recorded what he did about the curve back in 1998.

So for today, she is back in the garage with the radiator tilted forward and I'll have a look at the distributor innards on Sunday, probably.


If it turns out that the distie is knackered I feel tempted to get a 123Ignition Tune electronic distributor unit, but they are rather expensive. That's the one you can couple up to a Windows Laptop and then literally DRAW the advance curve you want to try-out and then upload it to the distributor.

http://www.123ignition.se/produkter.php?brand=ford



See this thread for last year's discussion on the 123Ignition Tune.
lotus-electrical-f38/123-ignition-tune-t25977.html

[AHM]

So I loosened ant rotated the distributor to be a more sensible 12 degrees at 1000 RPM and this caused the idling speed to drop drastically (is that normal ?? ), so I had to screw in the idling speed screw to get it back to 1000rpm.

Bill,
This is not your usual logical and considered approach! Don't confuse static and dynamic timing (you may need to add them together) - you have wound out the advance at 1000 rpm so you won't get to the top end and the static timing will now be way retarded hence the tickover.

It seemed fine in the video so I would put it back to where it was - not too much wrong with the timing. If you are using a timing figure from the manual retard by 2 degrees for low octane fuel. This will give you a good starting point - you can fiddle later! Stick to the static figure for now and you won't be too far wrong.

Ideas for hesitation that has appeared from nowhere
Check float levels
Clean carbs - Fit a proper fuel filter
Replace fuel
Replace condenser
Check points
Check coil
Don't touch anything adjustable!

[billwill]

Hmmm, could be ..

I was assuming that the dynamic advance does not start until after 1000 RPM, as per the bottom curve 41225a in Miles Wilkin's book. I vaguely remember reading that the centrifugal weights don't start moving initially at low rpm. Alas the bottom of the curve of the 41189 distie in the book is undefined, it doesn't show whether it is static (horizontal) or whether it continues downwards to about 3 degrees at 0 rpm.


I will have another go tommorrow, other things to do today, and with the strobelight I will be able to see if the advance of this particular distie goes down below 12 degrees at rpm less than 1000.

I will probably take it out & give it a good clean and oil in any case.


~~~~~
<a bit later>

Aha, after consulting both my older and later Lotus Elan Workshop Manuals, I see that when using a timing light it should be 18 degrees at 1000 RPM, so I was indeed wrong to set that back to 12 degrees, it wasn't far off correct before. However it should go on up to 35 degrees at 6000 RPM, which I don't think it is doing, so a distie inspection is still needed.