When the car hasn't been used for a few days it is hard to start. The electric fuel pump clicks but it takes many cranks to get it going. Once it is warm, however, it runs fine. Can anyone give me some advice on what might be causing this problem?

 

If 2.4 ~ This has been an issue from day 1 with the Solex carbs on the Mk1. It was mentioned in most original road tests at the time. Hard cold starting.

The best you can do is ensure that she is in an optimum state of tune. Chokes set properly for adequate enrichment., good plugs correctly gapped, healthy leads, points, condenser, distributor cap, coil, rotor, correct timing, healthy battery and proper earthing of the body to the engine.

A new electronic high energy ignition system or a Pertronix Ignitor point replacement with a Pertronix 40,000 volt Flamethrower 3 ohm coil might help.

 

If this is a known problem with the 2.4 then the chances are it is going to happen a lot in cold weather. Why not buy a can of Easy Start.Spray this into your air filter and you should have instant firing. I use it on my lawn mower engine which has a rope pull start and even in the spring when the mower has been sat all winter a quick spray and one pull does the trick.

 

That puts a lot more light ends in the fuel & will be a large aid to cold starting. The oil companies (my background) make summer grade & winter grade gasoline to try & help with this. If a low use car still has summer grade fuel in the tank it's really going to battle to start in a cold winter.

 

Thanks! I'll give thisca try.

 

Thanks for the advice.

 

Thanks.

 

There's also the Powerlite starter motor that spins the engine faster and demands less power from the battery. I think that Rob or Glyn has one.

In the event that your carburetors are due for a rebuild, it might be worth thinking of swapping to SUs (or ...). With SUs and several other carbs from the classic era, I'm told it's better to rebuild old ones rather than buy new.

I forget where you are in Texas. Is it a part where it's cold in winter?

 

Dallas can get damn cold in winter. My first experience of black ice on bridges etc. Snowed in fairly often. But not Chicago type cold. I have an original starter motor. I think Cass has a fancy high torque unit. My 3.8 starts on the button but has Pertronix ignitor & coil and SU Carbs. Those Solex carbs were known to be troublesome yet Jaguar persisted with them.

 

In Houston and I think most areas close to the coast, winter hardly exists. There are one or two days in January or February when the weather comes from the north and you can wear a coat. I remember a Christmas day when it became too hot to stay outside. Others have told me that Solex are less than wonderful, especially compared with SUs.

 

Yes, The Maritime effect keeps the gulf coast mild to hot & sticky. Those Solex carbs were awful, They only fitted SU's to the 240 with the head update.

 

Yes I replaced my original starter motor for a high torque one several years ago. Previously I was having problems with a very slow turn over and therefore starting problems in the winter. I use my S Type all year as a wedding car and needed reliable starting so had the original starter rebuilt but it did not improve the speed of turn over very much. Having changed to the new high torque starter I can tell you that it felt like I had forgotten to replace all the spark plugs the engine turn over so well. No more starting problems.
As for originality I have kept the original starter motor but to be truthful you cannot see the new starter motor from the top of the engine bay and can only just see it from the bottom so visual originality is not really effected.
This one of the upgrades to my S Type I would highly recommend along with the alternator in the original generator casing known as a Dynalite so you can run negative earth but not show it..

 

The reason Jaguar persisted with the Solex carbies on the 2.4 was for cheapness in manufacturing. The engine with Solex carbies attached and drivetrain including gearbox tail shaft diff. etc. was assembled on a frame and the body was then lowered over the whole assembly.

With the 3.4 and later 3.8 the SU carbies could only be fitted to the engine after the body had been lowered onto the engine and running gear. That probably added a fair bit of time and expense to manufacture the vehicle.
I have modified both my MK1 and MK 2.4 cars with SU carbies and it is definitely worthwhile from both a performance point of view and also ease of tuning.
The 11/4 inch Solexs are really choking down the engine. Fitting the 1 3/4 inch SU HD6 carbies increases the carby area by roughly 95%. Check the maths ( Pi R squared).
In addition using the electric start carby with a switch under the dash ensures an easy start every time.

This carby change procedure was endorsed by Jaguar who also recommended a straight port head and larger exhaust system which should increase the 2.4 HP output by 30 horsepower.
I think I am getting at least 20 HP with the carbie change and the larger exhaust. It definitely makes them want to boogie.

Bill Mac
MK1
MK2
S3XJ6
X300
15 previous Jags MK5 to X308

 

Bill ~ I have always thought that fitting those damn Solex carbs was Lyons saving a few bob. Thanks for confirming. With the 240 you got rather a nice engine & set up.

 

Glen
I also think the English were fairly obsessed with fuel economy. I am not sure when petrol rationing ceased but understood it continued into the fifties. An ex-English work mate told me that rationing was nearly re-introduced during the Suez crisis.
Perhaps the Solex carbies were part of the limitation for fuel economy. As I previously mentioned they really choked the engine down from it's potential.
Bill Mac

 

Yes ~ another consideration. The 240 was rather nice whose engine now boasted a power increase from the earlier 120bhp to 133bhp and a small torque increase from 144lb ft to 146lb ft at 3,700rpm. The main benefits of this were that the car could now exceed 100mph with ease for the first time and that its high-speed acceleration was improved. The heart of these improvements lay in the straight-port cylinder head of the 4.2-litre E-type engine that had replaced the old B-type cylinder head. However, the 240 engine also had a new water-heated inlet manifold, which carried two SU HS6 carburettors in place of the Solexes on earlier 2.4-litre engines. A paper-element air cleaner with twin intake trumpets replaced the old oil-bath type, and a new dual-pipe exhaust system made the most of all these changes.

credit Taylor.

 

everybody has a trick for starting the engine after it has been sitting for days or months.

I start my XJ6 by placing the gearshift in D (Drive), then turning the key to START holding it for around 5 seconds while listening to the fuel pump "charging" or "priming" the fuel system. I do this 4 or 5 times in a row depending how long the car has sat. This results in instant starting of the 4.2 fuel injected engine.

I used to do the same in my 3.8 S type with both tanks and with identical results before the engine was rebuilt. (machine work has been completed but engine is still stored unassembled).

you might try this trick to see if it starts the 2.4 engine quickly in cold weather. Place the shifter in any forward gear if manual, or in D if automatic, turn ignition key to ON, then press the start button so you can hear the fuel pump "charging" the fuel system. Repeat this 3 or 4 times, then place shifter in N or D. Engine should start quickly.

 

The 2.4 litre engine in the E1A prototype and a racing Mk1 in the 1950s reached close to 170 bhp on twin SU HD8 carburettors and an 8:1 compression ratio. That's quite impressive for the time and I don't think the 2.4 received much priority in development.

Another thing to check when cold starting and stalling durimg warm up arise is moisture on the distributor due to very small, almost undectable and otherwise totally insignificant leaks from the radiator top hose.

 

Sorry Jose but I don't understand how this works. If the car is in drive then nothing is happening other than the fuel pump filling the fuel bowls which would happen even if the car was in neutral with the fuel pumps ticking over. Having the automatic gearbox in drive just activates the inhibitor that stops power going to the starter motor so the car will not start in gear. If it is a manual and you have the car in a forward gear and you push the starter button with the ignition on the car will try and start and you need to either have your foot on the clutch, brake or have a builder on speed dial to come and repair the back of your garage wall once to reverse the car out of the debris.
Do you have a theory as to why your method of having the gearbox in drive should work?

 

In regards Jose's advice it is quite correct for XJ6 series 3 fuel injected automatic cars and I have used it on numerous occasions particularly on restarting on very hot days with an already hot engine. It allows you to purge the hot fuel rail with cooler fuel from the tank to avoid vaporisation. ( I have owned this series 3 for over 30 years)

However his advice does not apply in any way to MK1 and MK2 cars which are carburetted.

Starting aerosol fluids are one way to go.
Another is to improve the spark. Both my MK1 and Mk2 have had their ignition systems modified to resistor start systems where the coil is 8 volts which is protected by a resistor while the engine is running. The resistor is shorted out by a relay when the starter motor is engaged. The starter motor will generally apply a big load to the battery which typically gets pulled down to 8 or 9 volts. Consequently the 8 volt coil will produce a solid spark when the starter is engaged.
This "mod" is very cheap and reliable.

Bill Mac
MK1
MK2
XJ6S3
X300
15 previous Jags Mk5 to X308