Fuel problem

[JeffRoo]

Hi all, need a little guidance if possible. 1.9DG mechanical fuel pump as standard.
The problem: when the engine is hot and I turn it off it will not start. Had me the RAC man to see it and he got it started after it cooled at bit using a squirt of super start plus down the carb. Once it was running it stayed running and I drove from North of derby to Coventry to pick up my daughters dog. Turned it off and it won’t start again, tried a squirt of said stuff and it’s trying to catch but nothing. Going to wait until it’s cooled down before another squirt.
Mr RAC tested coil, sparks , rotor arm and all a ok, so it’s something to do with fuel? Have recently changed all of the fuel lines for e10 approved except the thin plastic pipes.
Any pointers/ ideas greatly received.
Thanks

[TONYT25T25]

Are you using the set starting procedures for a cold and hot engine iaw the manual. Also worth looking at this post.
viewtopic.php?t=176867

[DoubleOSeven]

^^ Either this or the choke flap isn’t opening. When it’s hot take the pancake off, the choke flap should be open.

[Stesaw]

If you're still in Coventry Jeff I could come have a look.

[JeffRoo]

Hi all
Thanks for the info and thanks Steve for the offer of popping over to take a look. In answers to the questions
1. Yes I am using the hot/cold start procedure
2. Yes the choke flap is open
3. Made it back to Taunton Steve

Headed over to Halfords and bought some easy start, squirted as per instructions and it started straight away. Still need some more thoughts as I don’t want to squirt easy start every time

[TONYT25T25]

What type of carburettor do you have fitted, worth mentioning as there are a lot of members who are up to speed on probs associated with various types.  Are the vacuum pipes connected correctly and have no breaks or splits in them, not a boffin myself on carbs but have looked up on issues, as mentioned above would check that the choke flap opens and closes when it should. Could also be vapour lock due to pipes being close to a heat source.

[DoubleOSeven]

I had this on my Velle - turned out to be solenoid on the starter motor was on its way out? Again, only happened when it was hot. Two bolts take it out and get it serviced for £40. The 'super start' is taking the effort away from the fuel pump in bringing the fuel up, so even a slight kick from the starter is sufficient. I would go through these service items too though, while you're in there:

1, Change those air lines from the back of the Pierburg, there's only x2 - one to the airbox, one to the dizzy
2, Fuel pumps are cheap, order one of those while your at it + x2 gaskets. Don't overtighten it though onto that brittle bakerlite base
3, That new fuel line you put it, is the fuel filter round the right way?

Did the RAC check the battery? It may not be giving the starter enough. Should be ~12.5V static and ~14.5V when running. Quick Multi Meter test required too.

[JeffRoo]

Thanks doubleoseven, I’ll change the pipes and check the fuel filter, pretty sure I fitted it the right way round. Will also get a new fuel pump, gaskets and I’m thinking fuel push rod?

never thought about starter motor being an issue, I did change it r years ago and seems to turn over fine. Battery was new last year and has always had a trickle charger fitted in between use, but always worth checking

will report back

oh and it’s a pierburg carb

[Stesaw]

So the engine turns over when warm but doesnt fire? but if you spray some easy start/carb clean whatever in the carb it starts?
Maybe the carbs got a perished diaphragm, or some iffy wiring perhaps on the fuel cut off solenoid. I'd check the solenoid when the engine is warm, have the key on and pull the connector off it and plugging it back in, there should be an audible click.

[JeffRoo]

Hi all, just a little update
the cut off solenoid works as prescribed, thanks for the knowledge 
I have changed the dizzy cap, rotor arm and shield. As well as the fuel pump, nice shiny new pierburg mechanical pump, and fuel pump rod, all from BW (great service as usual!).
I also checked I had fitted the fuel filter the right way round…..doh! Nope…… what a numpty.
everything starts as it should so fingers crossed it has solved the issue, I’ll check it next weekend when I’m on my way to the bug jam. Not normally my thing, but heading over with a couple of mates. 

will let you know if all goes well.