Starting problem when hot + fuel pump

[vikla]

A number of times recently I have been out in the car on a hot afternoon. I leave the car for a while (e.g. 1 hour) come back and it won't start. After leaving it for a few more hours, and everything has cooled, down it starts perfectly. Just happened to me this afternoon even after I used the car in the morning OK.

I have read all the posts about fuel vapourisation, plus checking the coil, etc.
Someone at my local e-type centre mentioned it could be the fuel pump not working when hot.
So this afternoon when stranded I unscrewed the cover plate to access the pump. It didn't feel hot in any way. I banged it gently a few times but with no result. When I switched on the ignition there was not the familiar ticking as the pump activated and got up to pressure (without the engine on).
However after leaving the car for a few hours I switched on the ignition and immediately heard the ticking as usual and the engine then immediately started. As a result I came home thinking a new pump will fix the problem.

However I have just read this post which implies regular ticking from the pump is not necessarily correct and could be a leak in the carbs -
http://www.etypeuk.com/forum/viewtopic. ... c&start=10

As I said before when switching the ignition on I always get a quick burst of ticking and then a tick every so often but quite regularly . And then when the engine is running a more regular tick.

The question is should I get a new pump or not or look elsewhere in the carbs?
Also what exactly makes the ticking noise in the pump?

[ChrisC]

I recommend buy yourself the electronic version of the SU fuel pump as it doesnt have the problem with worn points "stopping" it working. It is possible that this is your problem - sticky points but I dont understand why this would be the case when hot.

The fuel pump ticks each time it pumps the fuel - if there are no ticks it slows right down to about 1 tick every few seconds. On first startup it is more of a Brrrrrr as I imagine fuel is not up to pressure.

[christopher storey]

If you can hear the pump ticking it is unlikely to be the pump, and if it were not working properly you would certainly get fuel starvation symptoms whilst running. I have had this problem with several cars and it is a damned nuisance which I have never conclusively solved . I should try a. keeping a spare rotor arm in the car, and swopping it over if you get the problem, and/or b. keeping a spare coil in a cool place

PS I do find that leaving the bonnet open for perhaps 20 minutes tends to cool things enough to get a start even with the original components

PPS I also find, particularly with my Mark 2 , that spinning it over for say 10 seconds with full throttle ,and then coming back to about 1/4 throttle as for flooding, tends to help

[vikla]

Nice hot day again so went out to reproduce the problem. Sure enough wouldn't restart after a decent run.

With the ignition on I cracked open one of the banjo bolts to a carb - lots of petrol came out, so I guess the fuel pump is working OK.

Next looked at the coil. It's a standard Lucas one, about 5 years old. The resistances were as follows: across the 2 electrical terminals 1.2 ohm, from terminal to HT connector 8500 ohms.
These seemed rather low to me, however I can't say how accurate my multimeter is.
I thought coils came with either 1.5 or 3 ohm primary (?) and about 11k ohm secondary.

BTW - car started again shortly after this investigation.

Any views?

[Heuer]

Stick in a new coil. I used to use the Lucas Sport DLB105 (?18 from SNGB) until I went with EDIS. Bosch Blue is another good one although the colour is not exactly near standard.

[D COUPE]

The fuel vapourisation is a little bit of a myth. Im not saying it does not happen but the most likley cause of non starting is the breakdown due to heat of the ignition system side of things.

The V12 has fantastic under bonnet temperatures but always starts NOW with the new OPUS system.

I used to blame the Fuel vapourisation when I first aquired the S3 but was told by a wise old head it was the igntion system breaking down and so it proved to be

DC

[paulj]

Hi
I have had the same problem
and struggled for ages to cure it
in the end the cure was having the distributer rebuilt
by the distributer doctor
now running good old fashioned points !!
and very pleased to say now completely reliable ( I could speak to soon!)
thanks Paul

[vikla]

Update on the problem.

I took the suggestion of changing the coil, in my case a Lucas DLB 198 high energy one, a specific one for electronic ignition systems. Also got a new 'red' rotor arm hearing they are better than the standard junk ones supplied normally. (Excellent next day delivery with free postage and cheapest price from Powersparks on eBay)

Lovely hot day again, went for a drive, got home, left the car for about 40 mins in the sunshine and tried to start it. No luck same as before.

Without the ignition on I cracked open the banjo bolts on each carb - lots of petrol under pressure came particularly from the front 2 carbs. Is this what you would expect?

Tried starting it again and this time the petrol pump made a funny whirring noise but still no joy.

Left the bonnet open and about half an hour later it started after a bit of hesitancy.

Last week I cleaned out the petrol filter on the engine bulkhead, quite a bit of rust type bits in the bottom of the bowl. Looked at it again today and there is more in there again. Is this a problem....

Any further views?

[Heuer]

You need to clean out the petrol tank sump filter before doing anything else. If there is that much rust in there it will clog the pump. Also check the three SU filters in the banjo couplings.

[1954Etype]

I like to put an in-line filter in between the tank and pump.

[vikla]

Checked out the carb filters which were all OK. However the rust bits are so fine they got through the filters and into each of the float chambers.
But the car runs fine when going.

Clearly need to address the petrol tank sump filter issue when I'm close to having an empty tank.

Is there a view that the non-starting problem when hot could be linked to dirt in the petrol pump somehow, even though the evidence points to a 'heat soak' issue under the bonnet?

[Heuer]

I have seen the sump filter causing problems with a car running OK for 20 minutes and then spluttering to a stop and refusing to start. Leave it standing for 20 minutes and it starts because the sediment has time to settle away from the sump filter. This is what another member here found in his tank sump:



And this is the filter that gets all clogged up:

[Hubert Dallard]

Hi,

I had the same problem with my S1 3.8l.
I've changed the original starter for a Hi Torque 1kw from Cambridge MS
It was ok but after the motor was redone, there were too compression when the motor was hot.
I've changed the starter for 1,4kw also from CambridgeMS. It was better but not excellent.
I've tested the electrical. The battery was a bit low. Ive turned the cam in the control box (carrefully!!).
Now it started immediately even when the motor is hot.
I don't know how is your starter, but for a first step maybe you can check the charge system.

[vikla]

Just thought I would give an update on my starting problem when the car is hot. I did clean out the fuel tank and found it was not too bad having had a new filter recently by the PO.

Next my attention turned back to the ignition system. At first I wasn't clear what type/make it was. However that was cleared up when I contacted Simon of Powerspark. He confirmed I had a High Energy black module for use with the low resistance DLB198 coil.



http://www.simonbbc.com/ignition-module ... nce-module

I bought a replacement one and have now tested it twice after a long run. Both times the car re-started OK after about 1 hour. So fingers crossed, I've solved it. I get the impression that older ones of these modules are liable to fail, having seen a few replaced at my local e-type specialist in Surrey. The latest ones now have a 3 year warranty on them.