Quote:
Originally Posted by Clarke
Update: I mentioned before that ever since I've had this truck, it doesn't matter if I disconnect the hard vacuum line to my vacuum advance; the timing remains the same and so does the idle.
Thanks to TJ, I decided to investigate instead of ignore it. Anyway, I disconnected the hard line from the back of the carb and hooked up my vacuum pump to the hard line. I tested the vacuum advance several times and obtained consistent readings. At 5 psi, I noticed the rod in the slot starting to move, and it would hold vacuum. At 14 psi, the rod would stop moving, and it would hold vacuum. I could pump it up a little higher, but the rod quit moving after 14 psi.
So I removed the reducer fitting from the back of the carb to inspect and it was clear. I also looked in the hole in the back of the carb with my inspection mirror and there were no obstructions.
Do my test results seem normal? Any suggestions on additional inspections? Maybe I need to dig a little deeper into the distributor? The mechanical advance weights/springs on the top side (under the rotor) are clean and move easily.
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Greetings Clarke!
There's no need to dig into the distributor. That's not where your problem is. The fact that your vacuum pump causes the vacuum advance to move, and that it holds vacuum tells you that your vacuum advance is OK and not your problem. If you connect a vacuum guage to the fitting at the back of the carb, dimes to donuts you will not get a vacuum reading when the engine is running. Check the gasket between the carb and the intake manifold to see if the area in that gasket to that fitting is blocked off. Without being there and not being able to see things firsthand, that would be my suggestion at this point, because there is something that is stopping you from having vacuum to that fitting. Hope this helps!