How to care for your car...

I just found this PM article on Google Books detailing how to care for your car ... in 1980. Most things apply to my '77 MGB, so I thought I'd share with people. They list 50 things people should do to keep your car running, such as (detailed instructions on) testing engine vacuum, cleaning the exhaust system, checking and maintaining the emissions system (which is actually quite interesting since most of those things have changed now)...

http://books.google.com/books?id=D9oDAAAAMBAJ&lpg=PP1&pg=PA139

Why don't they publish articles like this anymore?? Is it me, or have we as a general public become so dumb we can't find detailed technical articles in popular magazines anymore?

Carburettor Madness Part II (pictures this time)

• Carburettor (Weber DGV) fine-tuning
• How to adjust the idle speed screw, the long way (when all else fails)
  

• Actually got to drive around the neighbourhood for once, reliably.
• Managed 60 mph, easily (couldn't go over 30 before...)
• Fixed rough idle
  

Last time I discussed some general things concerning Weber DGV's and MGB's. I did some more fine-tuning today and learned that the 1.5 turns out on the idle mixture, as suggested by the webpage I discussed last time (by the way, still the best Weber DGV tuning page I've found) was not enough. I'm at about 2.25 turns out now which seems to be necessary to keep things running well (possibly due to the Peco header). The idle mixture screw is the one on the bottom of the carb, closest to the intake manifold (in an image further below I show where the idle mixture screw leads to). It's not the easiest screw to get to, but with some persistence you can get to it.

Much more frustrating is the idle speed screw, which is conveniently located in a completely inaccessible position while the carb is mounted (this may have been fixed on newer Webers). I found another screw next to the choke that links some stuff to that screw, and so in essence you can directly adjust the idle speed screw from there. I haven't tested the long-term effects of this, and I could be completely wrong, so if you try this be careful. The screw I'm talking about is shown in the picture below. Note that it is not directly attached to the choke, and as far as I can tell only affects how far the choke opens, but has a larger impact on the throttle plate.


My carb was so far out of wack I had to visually inspect the idle speed screw and the location of the throttle. When you turn the carb upside-down and look in the shafts you should be able to see three holes (open the throttle; see image below). These holes are outlets of various fuel circuits, and are activated based on how open the throttle is (interestingly, note that the secondary shaft only has two holes which are only activated when you're really flooring the accelerator; not shown).


I adjusted the idle speed screw directly linked to the throttle (so, not the screw near the choke as described above) so that the right hole, the 'highest' of the three holes, is just covered. The image below shows the right hole just peeking out, and thus how you should not have things. Make sure you cover that hole entirely. Put the whole thing back together, and make fine adjustments from the screw near the choke.


In a previous post I called the Peco exhaust noisy and unpleasant, leaving me with a ringing in my ear afterwards. Having properly adjusted the carb the sound, though still rather rough, was pleasant in the sort of roar one expects from a performance vehicle. Idle was very quiet, full throttle ear-deafening, in between pleasantly throaty. I bought this exhaust for it's performance aspects (which I have already noted - it works), but if you're looking for a comfortable drive I wouldn't recommend this.