Alfa Pages

Pedro · Guest

Need some help. I took my car (Alfa 33 '88 1.5 Ti Veloce) for an MOT and they found that the CO2 was too high. They fiddled with two screws, one on each side of the engine (I'm showing my deep mechanical knowledge here) which brought down the emissions to the required level. However, prior to going in the engine seemed fine (ran smoothly) but now at idle the whole car shakes quite significantly. I didn't notice until later on, after I had driven off. I am reluctant to go back to the garage as its a bit of a trek. Is there anything I can do to re-balance the engine? Is it something that I can do?

Eddie W · Posted: Wed Mar 17, 2004 10:25 pm Post subject:

Hi Pedro, sounds like they have your carbs out of sync. There are only two single screw adjustments on each side and niether affects mixture as such. the horizontal screw at the rear of the carb is to adjust the throttle opening at idle and by carefully listening through a piece of rubber hose and adjusting to get the hiss at the same strength is your way of synchronising the carbs. The vertical screw on each is to then adjust so that the linkage opens both at the same time and is adjusted so that a 1mm feeler just fits between the end of the screw and the arm of the linkage. Any discrepancy here will show up as roughness when the engine comes off the idle until about 2500rpm or so. The idle mixture screws are low down on each barrel in a recess and adjust out for rich and in for lean. Hope this helps.
Regards Eddie
_________________
A LITTLE FURTHER A LITTLE FASTER

loui · Alfasud Joined: 22 Feb 2004 Posts: 29 Location: Scotland

Its helpful to have a Holts Colour Tune kit to balance/set the carbs.
Comes as a dummy spark plug with a window and a small mirror attached.
Lets you see the combustion in the cylinder. Instructions included with the kit. When the flame in the cylinder is a bright blue the carb is set up properly.

I used to let the MOT station tamper with the carbs for the Uk emmissions test. Every time the car went for an MOT it came back shaking like a leaf. Didn't have access to a gas analyser to do it myself.
Found with the colour tune kit the Co2 emmission was well within the limits for the test.

garciaae · Alfasud Joined: 01 May 2003 Posts: 25

I've been searching for holts carb kit in google but I've not found anything. I'm very interested in it. Could you tell us more about it?

Thanks

Rob (Perth) · Guest

I was going to tell you you don't have much chance of finding a Colortune these days, with most cars coming out with EFI. But then I came across this address almost straight away:

http://www.aep.bigstep.com/color.htm

Godd luck.

Cheers,

Rob

Pedro · Guest

Many thanks to all that replied. I shall try and have a go using the advise. Got to admit that the shaking is a real annoyance.

Pedro

loui · Alfasud Joined: 22 Feb 2004 Posts: 29 Location: Scotland

Bought my colour tune in Halfords in the Uk. Gunson still make them.

I was surprised when I bought it. Thought they had gone from production a long time ago. Halfords also had battery aid tablets. Battery not too well, chuck a few in and make it better.

Ps: I don't work for Halfords or offer any endorsment of the company.
Expensive for parts but good for pinstripe and stickers.