Shawn sez
“Thomas,
Sounds like you may just have a vacuum leak. Could be a bad hose, like to the distributor or the big one to the brake booster. Check all those, and maybe even block them all off and check your timing and lastly the idle mixture on the carb. Also pull the plugs and see if any of them are black or wet (showing that that cylinder is not firing).”
Well, tonight I checked the suspect spark plugs – all okay. I replaced the PCV valve with a new hose, even the old hose looked very good. I pulled a block off plug off the carb metering block, and could see just a shade of daylight shining through to the inside. GOTCHA!!! I replaced all the plugs on the carb (like I said earlier – I have no vacuum advance on the distributor and no brake booster either), and she was easy to keep running at 800 RPM. The engine was cold, so it wanted to drop to 500-600 area and quit, but it would idle at 800 just fine if I kept a small bit of pressure on the pedal. Looks as if we found that gremlin. Tomorrow I will take a road test to warm her up, and adjust the idle to about 800 afterwards.
If anything else creeps up – I will keep you informed.
Oh – and I will never underestimate a vacuum leak again.
Say it 3 times…
I will never underestimate a vacuum leak again
I will never underestimate a vacuum leak again
I will never underestimate a vacuum leak again
Thanks all!
TJR
Clovis, California
72 Chevelle, in shambles
