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Further to my carb issue: Fuel issue!
Posted: 04 Dec 2009, 19:45
by ZanettiZA
A new question:
Since most of what I have been doing on my Fulvia thus far has been tuning related, ie. mostly idling or very sort spurts of driving. I ran out of fuel in the process I therefore when and got 5L fuel and put that in the tank. According to my trip counter, which is accurate, I have done a total of about 1.5km driving (around the residential complex where I live) and about a total of 30 mins of idling.
Is it possible that I could use 5L fuel doing this? It seems a bit excessive to me. This has happened twice thus far, the fuel light comes on and shortly thereafter I run out of fuel.
She still seems to be running rich and this is causing the plugs to foul I have just today changed to NGK BP6ES from the BP7ES in an attempt to reduce fouling, it doesn't seem to have made a major impact though.
Any thoughts?
Further to Ralph's comments
HERE, I have the choke disconnected-they are fully closed. Yes the idle screw has some affect on the engine.
Re: Further to my carb issue: Fuel issue!
Posted: 04 Dec 2009, 21:17
by Ralph deMasi
Is it all the plugs and have you checked the fuel pump pressure?
Re: Further to my carb issue: Fuel issue!
Posted: 05 Dec 2009, 07:19
by ZanettiZA
Haven't checked the pump pressure, in terms of the plugs being sooted up, yes seems like all of them BUT I only loose no.1
Re: Further to my carb issue: Fuel issue!
Posted: 05 Dec 2009, 14:43
by Geoff
Check the pressure!
Some of the mech'l pumps are very sensitive to the shimming setup - a gasket thickness can take the pressure from 0-10psi. Really. You may be running too high, quite easily.
Re: Further to my carb issue: Fuel issue!
Posted: 05 Dec 2009, 21:11
by ZanettiZA
Now I'm really not sure: Took the car for a quick spin and checked the sparks afterwards.
No. 1 - sooted up
No. 2 - very lightly sooted
No. 3 - like new!
No. 4 - sooted up
My thought is that if there was actually a pressure issue why then do the sparks have colouration like this? I'm confused.
Re: Further to my carb issue: Fuel issue!
Posted: 06 Dec 2009, 05:07
by Ralph deMasi
You really need to check the pressure. If too much fuel is getting pushed passed the needle valve the carbs will not meter the fuel properly.
A typical vacuum gauge will also check fuel pressure, as mentioned previously you should be around 2.5 psi, not sure what that eauates to in bar or the other measures. I will look it up if you need them.
Was the car running right before you made your changes and what exactly did you change? Did you ever get a new condensor as Huib had suggested? Have you looked at your rotor and cap for excessive wear, carbon tracks inside the cap?
Re: Further to my carb issue: Fuel issue!
Posted: 06 Dec 2009, 08:49
by ZanettiZA
I will check the pressure tomorrow, I did replace the point with Lucas points, the condenser and the coil just to be sure, as well as the HT leads. The rotor seems fine I would like to replace it however.
My biggest issue is the cap, it is ok but..., I really want to replace it but I can't find a replacement part locally, I would get Huib's electronic ignition system but cash flow is a bit tight at the moment!
Do you think it could be potentially a weak spark (when under pressure) on the cylinders I mentioned due to the cap not being perfect? The spark is ok when checking outside of the cylinder.
Re: Further to my carb issue: Fuel issue!
Posted: 09 Dec 2009, 13:47
by Huib
If one of the plugs is like new, you may have no compression on that cilinder. Mixture goes through unused. It washes the plug and causes high fuel consumption.
You suspect the carbs. You are probably right. I would in any case still measure the fuel pressure and compression as these are easy to do before going through all the labour and possibly expenses of sorting the carbs.
.If 1 and 4 are sooted and 2 and 3 are not it may indicated twisted spindles.
Did we go through the adjustment procedure of the carbs? I don't remember.
Re: Further to my carb issue: Fuel issue!
Posted: 09 Dec 2009, 16:23
by ZanettiZA
No we haven't been through the carb procedure yet but I have been spending a lot of time tuning them and things have improved substantially. Perhaps you have a few tips?
I have checked the compressions and they are all basically the same...