So I re-installed my Weber recently and was running the vacuum line from the brake booster to the base of the carb. I put a T-fitting in the line since I couldn’t find a simple L shaped fitting, and ended up with one extra nipple which I capped off for easy access in the future. So now I have an easily accessible spot to hook up my vacuum gauge in the future, and the vacuum line is actually somewhat tucked away now. I was pleased with myself for thinking of it, it’s a simple touch that will come in handy but the whole process got me thinking about how things have changed over the years.
In today’s world of fuel injection, electronic ignition timing, throttle by wire, variable valve timing and lift, sensors galore, and OBD2 compatibility, sometimes knowing some old tuning basics can make you feel like you’re practicing a dying art. I think it’s amazing all the data you have access to at the push of a button nowadays. When it comes to doing automotive detective work it’s like we went from random guessing to DNA testing. Fun Fact: You have more computing power in your car than all the systems used to land us on the moon.
Where does that leave those of us old-schoolers though? If you’re the owner of a pre-OBD1 or 2 car (Or as I like to call it: OBD-none.) and you want to tune it or diagnose problems it seems it’s mostly up to you to learn, practice, and hopefully pass on the tricks of the trade to anyone who’ll listen. I know my share but I’m always trying to learn more.
One invaluable old school tool that doesn’t seem to get it’s due anymore is the vacuum gauge. They used to be the go-to diagnosis and tuning tool for most mechanics, yet nowadays they seem to be all but forgotten as being part of any shadetree mechanic’s tool set. Sure, I’ll admit I’m still relatively new to using one myself, but I can tell you that I am now a real believer in their value. I used mine today with the intention of using it to tune, little did I know that it would be used for diagnosis as well.
As you can see from the video there’s clearly a problem, but it seems the most likely culprit is some gummed up valve seats, and hopefully a little Seafoam will do the trick. Not being able to do anything about the problem immediately I still set about dialing in the Weber, first adjusting my fuel air mixture, then setting my timing as well. Using a light for timing is fine and in most cases recommended, however once you put an aftermarket carb on (Or actually ANYTHING that alters engine performance) then the ideal ignition moment changes. There are many other more sophisticated tools you can use to find this ideal timing setting but few things are as multipurpose, easy to use and cheap as a vacuum gauge. I had intended to make a how-to video about it (And still might) but I realized during the process that I really need a camera stand or a camera person.
WARNING About adjusting your timing using the engine gauge:
If done improperly it can damage your engine! Timing that’s advanced too far can cause knock (Detonation) which can harm your engine, so I would highly suggest doing a little research before diving right in with it. It’s not something that should be done by someone with no experience. A simple Google search will bring up several very informative sites on the matter. If you decide to try it you may have to take your car out and test the changes using your butt dyno (and your ears too) a few times before you get everything all dialed in perfectly. With all that in mind I honestly still can’t recommend it enough. Once you’ve set your mixture screws and dialed in your timing I promise you you’ll feel the difference in over-all power and throttle response. In my case I’m starting with a whopping 68 Horsepower from my EK-1, so every little bit counts!
Old school cars call for old school tuning tricks, tools and techniques so go ahead and try learning some today! Just think: When you do, you can show them off to your fellow car-nut friends and amaze them with your mad old school tuning skills. Even better? Tell them you practice a dying art.
Keep Em Rollin Folks!
Ethan – Editor