Okay here's a couple more questions for you guys. When hooking up the vacuum gauge I hook it to a line coming off the manifold, right? I did it using a gauge I found in the garage that had to be as old if not older that me (I'm 25). So I'm not sure if the gauge was bad or something was wrong with my engine vacuum. I set the timing right, I had the carb adjusted right, and it was still running amiss. Could my timing chain have a lot of slack in it. I'm sure it does. I've seen a motor with 5,000 miles on it have a semi-loose timing chain. If there is something wrong with a valve, lifter, or even the chain there's no way I'm putting that cast iron manifold back on. I don't what to break my back installing the dang thing. Besides I have an extra set of heads, RPM manifold, mild cam, and many other little mods from my other Ford hot rods over the years. Also how does an engine scope work? (the ones the automotive shops use). Also could it tell me if I had a bad lifter or a bad valve? What I mean is could it pinpoint the problem? Thanks for you help
Do you know how to read the various movements the gauge will make for various problems? Low and steady reading under about 14, can be late timing for what ever reason (timeing chain), ignition etc. A fluctuating needle at a regular interval can be a valve, spark plug, rocker arm or any problem that would cause one cylinder to misfire or cause low cylinder pressure.. A rolling needle can be the carb misadjusted. There are other combinatons of needle movements that show other conditions. Get into an automotve book that discusses the use of this gauge, for more insight. To get an idea of how bad the timing chain is, remove all the plugs, then see how much movement the crank will allow back and forth in rotation before the chain slack it taken up to move the cam and valve train.
As for the scope, there are different indicators that the technicians will look for that point to different things. The scope can plug into different areas to produce different effects and help narrow down the problem.
Jeremy; easier way to test timing chain. Remove the distributer cap, move the engine, and see how much movement it takes before the distributer shaft starts to move. Just my $.02. Earl
Thanks for the great idea Earl!!! I had actually never thought of that, I will use that in the future.
Vacuum Gauge Tuning Megawes, Take a look at this site for info on tuning with a vacuum gauge. It is pretty thorough. Also check out the rest of the tech site. I've found a lot of useful stuff there!!! http://www.centuryperformance.com/vacuum.htm
Wow, what a difference some knowledge makes. I read that column and it helped. Thanks Maxx. I wasn't sure what the needle was telling me before, but now I understand. Basically my car was running way to lean. I got the car running real nice and smooth now. Got the idle screws set at 3 1/2 turns out. That's what it likes. When the engine was running rough the vacuum gauge read between 10-14. I richened the mixture, messed with the timing, set the idle, messed with mixture, set idle, romped on it a few times and wah la the thing runs way better than it did before. The highest vacuum reading that I could get out of the engine was 17. I drove it around the block and it feels like a car again. Thanks guys for all your help, your knowledge has refreshed my brain and taugh me many new things, Thanks a bunch. Now It's off to the next adventure!!
congradulations!! The satisfaction of fixing it yourself is one of the greatest feelings. Now you have the knowledge that will last you a life time, and help you many, many times over.
Hey maxx. Maxx it's saying page can not be fond, but i know another link and will post it please don't get upset. this has very good details with photos on learning to read spark plugs, i hope it is to some help to any and all who are wanting to know how. http://www.centuryperformance.com/spark.asp When done reading the first page go down and on the right click on go to next page.
