Car in bits again...
AO Silver Member
Join Date: Feb 2007
Location: Hampshire, UK
Before I make a long journey...
Hello again - sorry to keep bombarding you guys with questions, but I have another query.
Now that my carbs are clear of crud and everything is running good, I've noticed that if the engine is under load (say climbing a steep hill at slow speeds, maybe with a bit of clutch-slipping) or just a quick hammer round my favoured test route (3 miles, up a hill, along a short stretch of A-road and down again), the engine idling speed increases appreciably. I had this problem once before when the radiator fan sensor failed in traffic, which I put down to fuel vaporisation in the carburettors. In that case the engine speed just kept climbing and climbing, but in fairness the engine temperature exceeded 100°C for a short while.
Now that the fan sensor is fixed, and the engine temperature stable at around 75°C (there's an error due to the use of a non-standard temperature guage), I'm starting to get the same problem.
The engine is an (approx) 1982 Green Cloverleaf, twin 36 IDF Webers, standard air cleaner, but no "snorkel" intake. The ambient air is coming from under the car (Green Machine is mid-engined, hence my concern), and may therefore be warmer than in a front-engine application. I am also using an electric fuel pump, with a Filter King regulator currently set to 2.5-3 psi, which is supposed to be OK for Webers, unless you know different!
Should I drop the fuel pressure to 1.5 psi (a guy at the rolling road once told me Weber/Dellorto's prefer lower delivery pressure), or do you feel some sort of cold-air induction is required? I can duct cold air in from the body intakes, but I would have to dispense with the factory air cleaner in favour of separate (boxed) K&N's or such like.
As always, any help would be gratefully received!
Alfanauts are GO!!!