Fuel pump pressure?

[910Esprit]

Nope - thats not right!   You should have a clear jet (like a good water pistol!) that squirts out of the choke towards the inlet valves.   

But I'm assuming the float chamber is full of fuel for the test?

Edited June 15, 2023 by 910Esprit

[Maggo54321]

Yes the float chambers are full and the pump is actually on for these videos.

All 4 jets point downwards, I've even taken one of them out and the hole is at the bottom so there's no way it could squirt forwards.  But I always thought it should squirt forwards as I've seen a Youtube video with them shooting out the fuel.

Here's a better video of this happening.

 

 

[910Esprit]

Interesting, looks like your pump jets spray vertically downwards - maybe that was a change with the introduction of the DHLA45's fitted to the HC motors.  As long as the volume and spray pattern is similar, you'll be fine.   But it is a worthwhile check to make sure the volume matches the spec in the workshop manual (but thats obviously not your current issue)

[Maggo54321]

Yes I’m going to measure the output of the jets whilst they’re off. I read that 40 full pumps should output 15ml of fuel per carb. 
 

Numpty question but what do these back holes do?  And a follow up numpty question but given that no fuel  squirts unless I pump the throttle, how do carbs actually start the car and then idle unless you’re pressing the accelerator pedal?

[910Esprit]

Bernoulli!  Cant see any black holes on my screen, but for air or fuel!

[Maggo54321]

Lol it was back not black holes. 
I’ve Googled Bernoulli and kind of understand now. 
 

Jesus these carbs are a pain. Shall I just dump them and go EFI??? Someone give me a good reason not to!

[jonwat]

13 hours ago, Maggo54321 said:

Numpty question but what do these back holes do?  And a follow up numpty question but given that no fuel  squirts unless I pump the throttle, how do carbs actually start the car and then idle unless you’re pressing the accelerator pedal?

As the inflowing air accelerates through the venturis the depression is what sucks the fuel out through the jets & to evaporate as it's drawn into the engine. The pump is there to add fuel only when you open the butterfly & the air  rushes in before the fuel catches up.

Having watched your video I can't imagine where all the fuel is flowing through, I'd recommend sending them to Eurocarb for a full reconditioning before risking a fire.

I'd also squirt plenty of oil into the bores before restarting the engine to replace the oil all that fuel has washed away. 

[Maggo54321]

£840 to get the carbs setup seems expensive to me. I’m sure I can get that cheaper locally. 
 

Or even change to EFI for that money and sell my carbs.   I am genuinely contemplating the Megasquirt setup as it would eliminate all this concern of carbs for the future. 
 

Noted re oil down the bores I’m ready for the smoke! 
 

 

[Chillidoggy]

As has been sadly demonstrated in another thread, £840 could be a cheaper option to a fire!

And if you change your fueling system, as strange as it seems it could potentially devalue the car.

 

[910Esprit]

And would present much more cost and engineering challenges than some well set-up dellortos

[Maggo54321]

Cheers again guys. I’m actually booked in on a locally recommended rolling road in 2 weeks time (had to book 7 weeks lead time) so providing I can get everything back on the car and the car starting by then, I hope they will advise on the setup and give me more confidence that all will be good for long term usage of the car. 

Update on the car is I’m pretty happy that the work I’ve done last night has rectified my fuel leaking and I’m just waiting for oil to turn up before changing the oil and filter before putting everything back together and hopefully a successful start this evening!

Fingers crossed!
 

[Sparky]

I can hear alarm bells ringing.  Fire alarm bells, to be specific.

Can you definitively state what the problem was, and what you did to rectify it?

[Maggo54321]

As per the videos, I took the top of the offending carb off and turned it upside down and there was no fuel coming out, this indicated to me that the needle valve was fine but the floats must have been sticking somehow.

Given this knowledge I swapped the tops over and at the same time cleaned the chamber as there was some crud in it. This immediately sorted the issue. 
 

Spent about an hour with them on test last night (fuel pump running and pumping the throttle and shaking them to simulate engine running etc) and I couldn’t replicate the issue anymore. 
 

I’m going to open them up again and just check all looks good. I will rerun the tests afterwards. 
 

I hear what you say about the danger, but I can only do so much before I have to trust them. 
 

I am going to investigate the automatic fire extinguishers too as I just cannot go on with the worry especially when you see the other thread and that blue one earlier today. 


 

[Sparky]

OK, gotcha, I'd failed to clock the video.  Have you confirmed the floats don't have holes in them?

Additionally, have you checked float chamber levels after pumping?