Idle on 32 DATR

[cheeky monkey]

Hello,
Noticed a slight lack of power on accelerating recently and then the car stalled when driving. Fuel was reaching the filter after the pump and the return fuel line wasn’t blocked. No obvious air leaks and the plugs, leads, coil, dist cap and arm were all good so I got the carb out for a look

I have cleaned the primary main and idle jets and the secondary main and idle jets, around the float chamber and accelerator pump.  (Visible traces of dirt in the primary main). I replaced the needle valve assembly and set the float level. With new manifold gasket on its base the carb was fitted & I got a nice fast idle on starting cold with the auto choke on, but once the chokes off and returns to slow idle the rpm is just too low and engine stalls after a minute.

Driving the car today the acceleration is fine, its just when stopping and slow idling I have an issue. I’ve double checked the idle jets and was careful to replace all the jets in the right barrel. On adjusting the slow idle screw on the carb in either direction, there is absolutely no change in the idle speed. Does this suggest the idle circuit is blocked ?

I have a carb service kit so will go back and do a more thorough job changing the other gaskets and diaphragms supplied ( I didn’t take out the slow idle screw to clean that passage). Looking at some other forum threads on fuel I have a nasty feeling that I’m chasing some dirt around.  Im going to drive the car the next few days to see if it settles out.  In the meantime, any suggestions on things to check would be gratefully received.

Graham

PS. I had the Rad recored whilst the carb was out so will report back on results when/if  I do some mileage.

[WestonE]

Hi Graham

It does sound like dirt stuck in the idle circuit so time with an airline or high pressure carb cleaner aerosol and protective eye glasses required.

Good Luck
PS Fit a good filter in line before the carb and replace all old fuel lines as they can crumble from the inside sound dirt into the carb

[mangocrazy]

An inline fuel filter is vital to my mind. Having a clear one on my Spider alerted me to the amount of crud that was clogging up the filter - the fuel tank being the culprit in my case.

Another Graham...

[cheeky monkey]

Hi Graham

It does sound like dirt stuck in the idle circuit so time with an airline or high pressure carb cleaner aerosol and protective eye glasses required.

Good Luck
PS Fit a good filter in line before the carb and replace all old fuel lines as they can crumble from the inside sound dirt into the carb

Hi Eric

thanks for the reassurance. Its back on the bench so will work through it with glasses and a mask on.  75% of the brake hose is done so nearly there.

One thing I forgot to label were the 2 coolant hoses that go into the choke. I cant remember which way round they go.. Does it matter.?

cheers
Graham

[cheeky monkey]

An inline fuel filter is vital to my mind. Having a clear one on my Spider alerted me to the amount of crud that was clogging up the filter - the fuel tank being the culprit in my case.

Another Graham...

Hello Graham!

I have just one filter (plastic cased effort) a few inches before the carb, which I check and change on a regular basis. Do you mean placing one before the fuel pump.?

cheers
Graham 

[mangocrazy]

Hi Graham,

I've replaced the mechanical pump on my Spider with a Huco electrical pump, and have the filter plumbed in between the pump and the tank. If anything chunky does arrive in the fuel it hits the filter before it can get to the pump or the carb. Since I've had the tank refurbished the filter stays very clean, but it's another line of defence.

Graham

[cheeky monkey]

Hi Graham

Makes sense. Thanks for the describing the set up. I will think about this whilst finishing the new fuel lines and getting things set up.
I renewed the rocker cover gaskets today just to give myself something else to think about !

regards
G

[peteracs]

Hi Graham

The coolant hoses just go into chamber, so either way is ok, just pick neatest routing.

Peter

[cheeky monkey]

Hi Graham

The coolant hoses just go into chamber, so either way is ok, just pick neatest routing.

Peter

Thanks for confirming. I have also fitted new silicone coolant hoses all round (supplied by Mark W) so the bay is looking much better. Now back to the carburettor