4.2 Engine cuts erratically

[oldp]

Hello everyone,

On my 65 4.2L the engine starts fine then runs ok for a few miles (5/7 approx) then starts to die when i begin to rev te engine closer to 3500 Rpm...sometimes it restarts as I downshift trough the gears...sometimes it just dies and I have to stop on the roadide for a few minutes before it starts again and run fine for another few miles before it cuts again.

I suspect a fuel feeding problem so I'm going to check the fuel feeding elements to see what's going on.
Your inputs will be greatly appreciated as go through this !
Here is suspect number 1 on my list, the fuel filter :

Wow it looks ugly in here !




From what I see in the filter, I'm going to check what's going on in the fuel tank !
However what's the good set up (stock or upgraded) for fuel filtering on an Etype ?
Thanks for your help !
Olivier

[Gfhug]

Olivier, start with simply replacing the element. SNG Barratt’s will supply them.
An alternative filter is the Malpassi Filterking, search on here to find comments.
Another possible cut out is from the coil overheating. Buy a good replacement.

Hope this helps

Geoff

[oldp]

Thanks Geoff !

From what I understand so far I can run two types of filters in the stock glass filter unit :
Either :
https://www.sngbarratt.com/Francais/#/F ... essence%60
Or :https://www.sngbarratt.com/Francais/#/F ... essence%60

Which one do you recommand ?
Can I run both at the same time ?

Thanks
Olivier

[christopher storey]

Also, check the rotor arm : many of these become conductive with heat and as a result short out to the rotor shaft . With a small drop in temperature , they become non-conductive again and the engine will start and run for a few minutes. A means of testing for this is to insert a layer or better still two layers of clingfilm between the rotor arm and the shaft . If the fault disappears, then it is the rotor arm at fault

[Gfhug]

Olivier, either will work. If you look at items at Barratt you often see a * or other symbols next to the number. I can’t remember what each symbol means but it is something like a modern reproduction or alternate item. But they still work. Sometimes you see upgraded items at greater cost, then you must decide which you want. And let us know how you get on.
Look here at their coils C30120 and C30120# to see the same item with different symbol

Bonne chance

Geoff

Yes agree with Christopher, buy only from here: https://www.distributordoctor.com/

[oldp]

After seeing how bad the fuel filter is, I've decided to go check the gas tank.
Gas tank seems OK, but I will drain it to have a close look and check the sump.
However the pickup tube filter is badly damaged so I will replace it.

[caveman]

Maybe also replace the gauze filter located in the top of the fuel bowl too, (easily missed);

[Jack the lad]

This sounds to me like the vents to the top of the tank blocked, so that petrol can be drawn for 7 miles but then the lack of air in the top of the tank prevents further fuel reaching the engine. Try driving it with the fuel cap removed.

[caveman]

Your initial description is what happens with poor quality rotor arms which become conductive with heat.
I had the very same symptoms you descibe in your initial post. Ensue you fit a Red Distributor Doctor rotor arm.
A search on this site will provide more information.

[DWW]

In cases like these like sudden cutoff or misfiring there could mostly be two reasons either fuel or ignition. In the case of fuel the supply lines, filters and tank breathing should e investigated and consumables replaced. In the case of ignition the first approach would be to check breakdown of insulation due to temp rise by the way of substitution of distributor arm or head and/or coil and capacitor where relevant. Hope this helps.

[oldp]

Thanks a lot to you all for you helpful insight !

As I have started investigating the fuel system I will first finish my clean up, test the car and move on to the ignition.
I've cleaned the gas tank by draining it, then I brushed all I can with a long paintbrush (33cm) going through the pickup tube opening and the fuel gauge sending unit opening. I then vacuumed it, and rinse it manytime with some paint solvent until there would be no residus in the sump hole after feeding some solvent into the tank. Quite long but worked quite well.
Now the tank is cleaned, the new pickup tube filter fitted, everything is bolted back up and the tank is full of gas again.

Next I'm going to clean and refurbish the clear glass fuel filter in the engine compartiment.
Thanks for your help

[chrisfell]

Re fuel filters. My home domestic oil heating system dates from the 1960s. The inline fuel filter is identical to the unit on the E-Type. I have a stock of fuel filters bought on line for both applications.

Paper filter and rubber gasket get replaced every time.

[44DHR]

Please read my posts #10 and #13 on this previous thread :-

viewtopic.php?f=4&t=12446&p=101005&hilit=Filter#p101005

The main point is that the filter in the glass bowl is fed with fuel from inside to the outside, so the glass bowl remains visually clear of debris, but could be seriously blocked internally. This allows the car to run to a certain fuel flow, but when higher flow is needed the engine will stumble. Easy to check by removing the filter and trying to blow through it. As it is such a cheap component, it is worth carrying a spare and also changing it anyway if the previous history on the car is unknown.
The other points raised in this thread could prove of interest, such as the fuel cap breather, the general condition of the fuel tank and fuel piping, plus the three separate fuel filters if you are running SU carburettors.
Regards,
Dave

[oldp]

Hello,
Fuel filter is cleaned and back on the car.

How can I clean the filters on my 3 SU'S and maybe the Su's themselves ?

Thanks a lot for your help !
Olivier

[caveman]

[rfs1957]

Another “piste” for you, Olivier, is HT leads.

Your symptoms are exactly what I had about 20 years ago, when it transpired that where the plug leads ran from the distributor, then against and over the cylinder head on their way to the plugs, the insulation was breaking down and the sparks were shorting to earth.

My cylinder head still bears the spark-erosion traces.

It was an intermittent and completely unpredictable phenomenon, making it very hard to trace.

Bon courage.

PS whilst looking at the fuel filter THINK VERY CAREFULLY about how the filter works ; somebody else will remember better than I (Heuer/David ?) but it can be necessary to invert/reverse the IN - OUT piping to the filter head in order for it to work correctly.

[oldp]

Hi there,

After cleaning the gas tank, fitting a new pick-up tube mesh and replacing both fillters and the rubber gasket in the fuel filter, I also took off the fuel filters at the carburetors and cleaned them (but they were really clean anyways). After that I went for a test drive with the fuel cap off..and after au few miles when trying to rev the engine a bit it shut off again.
So I think I will try to replace the distributor rotor arm and the coil and see if that helps.












Which coil do you recommend ?

[Gfhug]

Please see my response #5. DLB105 coil (C30120) buy from a reliable source and rotor arm from the distributor doctor: https://www.distributordoctor.com/

Geoff

And please add your name and car type to your signature. Much nicer to refer to you by your name

[christopher storey]

From the photo, that is most definitely not a usual rotor arm, and the distributor looks very different from standard - it might even not be a Lucas one. before you order anything, I think you need to establish the exact specification of what you are running

[chrisfell]

That looks like a Bosch rotor arm as fitted to a 123 dizzie. If it is, note that the life of the 123 dizzie cap and rotor arm is quite short. 30,000 Kms or 18,000 miles. The central electrode in the dizzie cap wears out, and misfiring starts. Replace them both. Check the part numbers on the 123 information sheet.

I've just looked at the photos again. I see a 123 dizzie and rotor arm but not an orange Bosch dizzie cap.