Strange behaviour!

[David Morris]

Hi All,

I am just waking up our Javelin, Black Shadow, after her winter hibernation. I have been starting her up fairly frequently, as I know the clutch doesn't like to be left undisturbed.

Had her running yesterday until up to correct temperature and thought all was well. Left her until the evening, and thought 'let's just see if she starts easily'. Fatal mistake! She was absolutely going nowhere, and sounded as if I had taken the rotor arm off! Yes, spinning over, but not a sign of life. Checked there was a good spark and that the carbs were full of fuel. Even tried taking out the plugs, which were new yesterday, and ignited them when washed out with fuel ( used the gas hob, but mum's the word! ). Still nothing! In desperation, thought of checking the timing. Couldn't be out, could it?

It is at least 90 degrees out! No wonder she wouldn't start! Time for head scratching. The possible cause I have in mind is that the bronze skew gear that drives the distributor has somehow got itself damaged. There is a small jet on the oil pump that is there to lubricate this gear...could it have become blocked and the bronze gear has stripped?

Before I start stripping the front timing cover, and all the timing gear behind, can anyone throw some similar experience on this?

Many thanks,

David

PS...Happy Easter to all fellow Jowetteers!

[Nick Webster]

Well, I don't know! You could try getting someone to turn the engine on the handle while you grip the rotor arm and see if it feels like it has got some massive back lash as it rotates but apart from that the only thing I can think to say is Happy Easter in return.

Nick Webster

[Keith Clements]

We had the offset tab at base of dizzy shear and gave similar problem. You could also take dizzy out after marking position and look down to see position of drive slot to see if as per manual at TDC.
Can you turn rotor arm? Pin may have sheared that holds to drive shaft.

[nigel jarrett]

I had the skew gear wear on mine which gave me 40-50 deg of play at the rotor arm , all due to the oil jet on the pump being blocked

[David Morris]

Hi All,

Many thanks for your help. I have taken the distributor out and the shaft and roll pin and lock ring all look fine. I can see that the offset slot in the top of the oil pump looks to be set in the right direction at TDC on number 1, although it's a bit dark down there and easy to misinterpret the larger and smaller segments on the shaft. I was encouraged by Nigel's comment that when he had his skew gear problem, he could move the rotor arm through 10's of degrees. Mine has just the normal amount of movement and seems quite positive. So, fingers crossed about the skew gear! It would be quite a bit of work to change it, setting aside the cost of a new one.

I have thought of using an endoscope through the oil filler tube to have a look at the condition of the skew gear? They are not too expensive now and you can get one with a diameter of 5.5mm, which might enable me to wriggle it down to the skew gear? Has anyone tried this?

Anyway, encouraged by all the comments, I have reset the timing and found that I have a really miserable weak spark at the plugs. You can hardly see it! I have a Accuspark electronic ignition currently, and see that the Hall-effect module in the distributor is 'fired' by a magnetic collar that sits around the original four-lobed rotor. I plan to back-convert to a conventional contact breaker system and hope this will achieve a better spark.

I will let you know how it goes.

Many thanks,

David

[David Morris]

Hi All,

Progress (?) Report,

She is still not starting properly! Runs erratically for a few seconds, then dies. So, further investigations proceeded. Firstly, I tackled the weak spark and ignition timing situation. I reverted to conventional points, so that I could see what was going on. Reset the timing correctly at TDC and investigated the coil, as the spark was pitiful. I purchased a new red 'Sports' coil from Amazon. ( Since lockdown, this has become a family 'go-to' for most things! ). However, I suspect red means nothing! I measured the primary and secondary resistances of an older ( plain aluminium colour ) coil, the Accuspark existing coil and the new one. The primary resistances were all the same, at around 3 ohms. However, the secondary resistances were, respectively, 4k, 6.5K and 10k ohms. Hopefully, the new one would therefore generate more volts? Fitted the new one and, yes, the spark, when turning over on the handle, was much better!

So, hopefully I had sorted the electrics? Now, I looked at the fuel. I have one of those older glass bowl filters and a subsequent in-line plastic one. I was very surprised to see that the petrol was bright green! I took the glass bowl off and the fuel didn't even smell right...it smelt more like paint!

I realised that during lockdown and since, I have done a very low mileage and only topped-up occasionally. The tank was around 3/4 full and most of that had been there for years. So, using the electric pump I have fitted, I am in the process of emptying the tank and will refill with new E5 fuel ( if I can find some? )

So, when I have some new fuel I will try her again and with fingers crossed!

Has anyone else had their fuel turn bright green?

All the best,

David

[Nick Webster]

David,
Some manufacturers use dye in petrol. It occurs to me that if some of the more volatile elements have evaporated (which I am sure they have) then the remaining dye colour will apparently become more vivid. These days I find that petrol also seems to have a more intense smell. Just a drop on the skin lingers despite repeated washing.

Nick.

[David Morris]

Hi Nick,

Thanks for your advice. Yes, I suspect a lot of the more volitile constituients of the fuel have evaporated. What's left doesn't really have the smell of petrol, just old paint!

I forgot to mention that another thought I had ( although less easy to cure? ) was that I was suffering from a stuck valve or two? I decided to measure the cylinder pressures when cranking, and the plugs out. On No.1 it was 120lbs/ft, which wasn't too bad. The others were a little bit harder to get the pressure hose to screw in properly, so I did a 'finger test' down each plug hole whilst cranking by hand. All were roughly the same as No.1, so I was encouraged.

Just managed to get the last of the dodgy petrol out, so I am off to find some E5!

All the best and many thanks,

David

[Forumadmin]

The dying symptom is typical with bad petrol.

[David Morris]

Hi All,

Cleaned out the glass filter bowl and the carb bowls, which had all accumulated some sort of grey sludge. Then managed to drain the tank, as much as possible using the electric pump, along with a new in-line paper filter.I know taking out the drain plug on the tank would have been preferable, or even removing the tank and washing it out! But with the car immobile in a single garage and the tank side up against the wall, this would have been a struggle. Also, taking out the drain plug, which probably hasn't been disturbed for 70 years might be asking for trouble! I then put in a couple of gallons of E5. Thankfully, she started and runs smoothly, so the dodgy fuel must have been the primary fault?

Lesson learnt for the future...don't leave fuel in the tank over the winter!

All the best and many thanks,

David

[Alf Heseltine]

At the time of writing, there is no requirement for ethanol to be included in super unleaded (97/99) grade petrol, so if you're driving a cherished older vehicle (or putting one into long term car storage), consider a switch to the UK's only ethanol-free fuels, Esso Synergy Supreme+ Unleaded 97 and Synergy Supreme+ 99.

David looks like you have solved it, the above info taken from Esso Information, maybe using Esso 97 before any layup would
help. I understand that some of the pumps show 5% ethanol but as explained by Esso it’s a legislative requirement only to
indicate the 5%.
Hope you are keeping well.

Regards, Alf.

[Forumadmin]

There are those that blame Ethanol for a whole host of issues. David's problem of dying after starting was not caused by ethanol as the same happened before ethanol was introduced into petrol.
Whilst some will swear they can tell the difference between zero ethanol and 5% I am not convinced. Neither am I between 5% and 10%.
Yes you may be able to notice slightly better power or miles per gallon using a more expensive brand, the difference is small. Of course an engine with a compression ratio greater than 9 probably requires 99 octane fuel.

[Mike Allfrey]

Hello David,

I am a bit late on this topic, but wish to make the following comments:

First, the ignition coil. The Javelin Instruction Book states that the terminals are under the coil. That is how the coils were mounted originally, which was OK for bitumen filled coils. Modern coils from Asia tend to be oil filled for cooling purposes, with the result that some coils miss out on the correct amount of oil - or, if installed 'upside down' the oil will not cover the bottom of the windings inside and local overheating is the result. Added to that, if a modern coil is mounted with the terminals at the bottom (or horizontally as per Jupiter), oil can leak at the filler hole screw plug, thus exposing the windings to a lack of coolant (oil). This happened on my Jupiter, but the leakage was not seen due to the tight fitting rubber boot at the HT lead. A boot part filled with oil, is sufficient to allow part of the windings to overheat. It started from cold easily, but after warming through, refused to run well.

Second, the petrol situation. I converted my Javelin to a SU pusher pump, mounted down on the chassis and wired the pump with an on/off switch (I used the fog lamp switch - here in Victoria, we are not permitted to have single fog lamps ($A60 fine in 1969!), so the 'F' switch now refers to FUEL. After a run, I switch off the petrol pump and wait for the engine to stop due to last-gasping of petrol, then switch off the ignition. Next cold start, the 'F' switch is pulled and the pump clicks away merrily until the carburettors have been filled. The engine then starts easily. That advice was provided by BP Australia and a Jowett engine is now shown as an example in their training sessions, to illustrate how the volatile components boil off easily in warm fuel systems.

I also use a CAV Delphi diesel fuel filter and water trap, change the element each year and drain off water at times.

All the best,

Mike A.

[David Morris]

Hi Mike,

Many thanks for the email.

Yes, I have an electronic fuel pump fitted and when starting from cold, I let the pump chatter away until it fills the bowls. This can be up to a couple of minutes. She then starts easily. It's also a good check that you have the right fuel pressure, too high and the carbs will flood. I have a regulator fitted in the line after the fuel pump, set around mid range, so as not to defeat the float valves in the carburetters.

My ignition coil is fitted with the connections upwards, as you recommend. For some strange reason, the resistance readings on the various coils I have seem to vary quite a lot. The primaries are all about 3.5 ohms, but the secondaries can be anything betweem 3.5K and 10K. I have one currently fitted which is 10K, perhaps in the ( mistaken? ) belief that a higher resistance equals a larger voltage? Anyway, it seems to work well and carries the description of a 'Sports' coil!

All the best,

David