Author Topic: Runing rich (Read 10411 times)

fiatfsm · « **Reply #15 on:** January 11, 2006, 04:15:10 PM »

no O ring then? Weird, because on the 126, at least Polish ones there is, and without it the mixture screw vibrates one way or the other! Maybe the 500 screws fit better?!

126cab · « **Reply #16 on:** January 11, 2006, 06:03:43 PM »

Hi there every one thanks all for your help in trying to fix my 500, but at long last i have fixed it, to cut a long story short, it was all down to fuel pump pressure (too much) yes i know i said i checked it which i did, it did not seem excssive which it was, so its now ticking over like a little sewing machine and im chuffed to little mint balls

Many thanks again for all your help.

Lewey · « **Reply #17 on:** January 11, 2006, 08:19:24 PM »

Too much fuel pressure did all that? Crikey, better check mine. What was yours showing and how much is ideal - 3psi or something?

126cab · « **Reply #18 on:** January 11, 2006, 09:07:18 PM »

Hi, i dont know what the correct pressure is m8, i just kept adding shims/gaskets until it stopped flooding, i can see the fuel is still going through looking at the filter. it has got 4 shims & 2 gaskets fitted.

ChrisRLewis · « **Reply #19 on:** January 11, 2006, 09:49:09 PM »

I am glad you got it sorted m8!
the fuel pressure data for the 500, 126 & Bis is quoted:>

Fuel pump delivery pressure bar: 0,15-0,20

Not sure on how you test it? but may be of help to someone?

C

126cab · « **Reply #20 on:** January 11, 2006, 10:23:36 PM »

Hi Cars, thanks for that m8, mine was just guess work but seams fine now.

PaulB · « **Reply #21 on:** January 12, 2006, 01:02:31 AM »

Nice one.

The carb should not flood. The float valve should shut off the supply if the chamber is full - the pump should just idle, so it looks like the carb will be in need of repair or replacement at some point, unless the pump is the wrong one? The 500K had a different pump to the various models used on the 500 and 126 as the K engine is pretty much gravity fed apart from when going down hill.

I can't find a part number for the K pump - there were at least 4 for the 500F and probably many more for the 126.

Axel Gerstyl do a pump (18 euro) for the K, they also do the bakerlite spacer etc. They do a repair kit for your carb for 21 euro.

the 500/126 center (Fiatclassic.com) have a set for 15 euro or a carb for 131 euro (ouch).

126cab · « **Reply #22 on:** January 12, 2006, 12:21:07 PM »

Hi Paulb, thanks for the info, the needle valve is ok as i cannot get air through when shut and i can also create a vacum in the fuel pipe when needle is closed, the pump that is fitted on the car was fitted new the day before i bought the car so im asuming it was just too much pressure from it as once i added the shims all was well ie plugs nice colour no flooding/ hunting and no stalling.

Ps perhaps tho after 43 years i should get one of the kits you mention m8

PaulB · « **Reply #23 on:** January 12, 2006, 06:37:55 PM »

If it works it works, so I guess there's no use in fiddling with it any more. Its a shame Fiat didn't put a fuel return on he 500 as it avoids all this and helps keep the fuel and carb cool - especially handy on an aircooled.

Android 360 · « **Reply #24 on:** January 14, 2006, 11:18:04 AM »

i may fit an oxygen sensor from my EFI nissan to the exhaust so i can hook up an air/fuel ratio guage. thats always a good way to see what your mixture it like, takes the guess work out of adjustments