Carb Tuning.

[RealizE]

1synapse1: Yepp, the carb has a fuel in and a fuel out. Atm, there is a T piece connecting both input and output pipes together with the main fuel line.

[Tex]

If you want your carby checked after all this you might want to try Tilley's in Brookvale. They're supposed to be the local Weber experts.

Tex

[1synapse1]

Hey Realize
I had a problem once similar to your own when i first put on the 23/36
I had the return blocked up and it would do similar things but the car would almost stall and stop accelerating.
i then added a T piece as you did wich improved things but it was still not right.
I then removed my fuel filter and it was fine after that (with changes to jets and float level to get it 100%)

must have been the filter not flowing enough fuel.

ps webers only like around 2 or 2.5 psi - definately no more.

[Tuna]

Our weber gets 7psi fuel pressure when off boost, daily driver, no probs.

[karl_2ltGC]

Realise, my car didnt like to rev past about 5,500 with my old jap dizzy....i then used my bosch one(that i had on 2ltr) with hemi6 ignition module and shes now all sweet.

Is the dizzy a electronic one???

[RealizE]

Nope, the dizzy is a cruddy old points one...

[karl_2ltGC]

Originally posted by RealizE
Nope, the dizzy is a cruddy old points one...

This could be your problem.
Is there any easy elec dizzy upgrade available...if so, DO IT!

Also i hope your not using some dodgy old stocker coil

Could pay to go around with a multimeter to make sure all eaths are good and the coil is getting 12volts ect.

[RealizE]

Also i hope your not using some dodgy old stocker coil

Ummm.................... ITs not THE stock one, but a very similar replacement one....


- There is apparently an elec dizz that fits (ive seen one is Spac's car) but ****ed if i can locate one anywhere in Sydney.

Do you think i may need to get the dizzy regraphed ?

Either way, i think its time i stop asking questions and take the heapa to someone.

[TurboSuzi]

Try an electric pump off a Series 3 Bluebird. There good for about 7psi I think and I'm am running one on my 32/36 with no problems. My mate is also running one with his 40 mm down draught dellorto and it seems to keep up. Personally, I think it's a fuel delivery problem and maybe your mazda pump may not be delivering enough juice.

[Galantman]

another thing to check is that the carb is the correct orientation.
the float chamber should always be located so that under acceleration fuel does not flow away from the jets. the fuel will get pushed to the rear of the chamber, if the carb is oriented wrong, the fuel would be flowing away from the jets.

[Artsi]

Weber/Dell'orto manuals say 2 to 3 psi fuel pressure. Why deviate from that?
Overshot fuel pressure can in some setups overpower floats/needle valve, thus leading into flooding.

There can be two culprits for fuel starvation. Inadequate fuel pump delivery volume (as already discussed), and possibly one size too small fuel bowl needle valve. That will not show on fuel line pressure gauge (if one is installed).
Ruff guideline for needle valves in Weber/Dell'orto tuning carbies:

two off twinbore carbies (in 4-cyl engine):
400cc/cylinder = 1,75
500cc/cyl = 2,00

one off twinbore carb in a 4-cyl engine, add 0,50 to previous data.

More cc's in cyl, shift to even bigger needle valves.


-A.