Take a look at your spark plugs... If you just adjusted your rockers and you've got to have 14 degrees advance and 1100 rpm in idle just to keep it running (even with the cam upgrade), I would take a long hard look at that before you burn up a valve on a brand new engine
Yeah I think you are on to something and I hope i haven't burnt them already but I guess I will do a compression test tomorrow to find out. I followwed the directions with the rockers for adjusting and it felt fine. It is hard to believe that I couldhave tightened them down that much considering they are hydraulic. However I do have about 50 psi aisle, could that pump them up more?
I actually don't know jack squat about adjusting valves, or much about hydraulic lifters, except that I'm afraid to do it because I'm sure i'd screw it up!
Ultimately, though, with the compression test - If it turns out fine than you just wasted an hour or so you know that all your valves are in good shape... If it turns out bad, then you may have just saved yourself a TON of headaches!
(also, 1.5 inches of vacuum at idle seems low to me, and improperly adjusted valves could contribute to that as well)
I may not have been clear...in gear at about 700rpm it has 6-8 inches of vacuum which is still way to low for a cam that edelbrock says still should make about 12 inches. Butits vibrating a lot over thanks range very quickly.
i didn't mention though that it runs pretty good and pulls hard (my wife thinks its faster than her M3), but it idles like crap and just has some sort of issues below 1000rpm, plus the vibrating vacuum gauge tells me something is wrong.
Ok if the plugs and all the ignition are fine and you have your dizzy set on the right degree Adjust the idle mixture screws. Im not familiar with holleys but im almost certain they have them. see if adjusting them does any good. and what model wasyour old edelbrock carb?
not an idle mixture issue for sure. all that is properly been adjusted on both the edelbrock and holley using both factory settings and my own, then back to factory.
Vibrating vacuum is not a good sign. Perhaps you have one of the valves set too tight such that it is not closing all the one. Or a dead miss or two. Or at low rpm one of the cylinders is not firing due to weak spark or lean condition.
I would do a compression check.
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John Bednorz
1967 Shelby GT350, dark green, 347 stroker, 5-speed, inboards, #2206
1973 Mustang Convertible, white/white, black stripes, Q-code (351C-4V), ram air.
1968 1/2 428 CJ convertible, R-code, red/deluxe red, auto, finally finished.
"If you find the car of your dreams, ignore the price guides and pay whatever you have to in order to get it."
I honestly think some of the "lower" number is because I couldnt get my fingers in between the headers and twist the hose anymore so i might have had a pinhole leak for the gauge, but they are all within 10%, but overall low. I attribute that to the duration of the cam at 224 deg and Lobe Separation at 112 deg, plus my starter is a little slow to turn over. I didn't bother to do a wet test since all were so close.
I did readjust my lifters before doing the test so who knows. All spark plugs were pretty good, a little on the whitish side but still tan except for one which was a little black, but not quite oily. Any ideas?
For the most part it settles down kind of slow. It tends to stall about 100-150rpm above the idle speed and then continue to idle down to whatever I have set it at.
i dont know where else to look! But i had a hunch about the coil. The specs for the one i ordered says it should be 1.5 ohms for primary and 10.5K ohms for the secondary...mine is showing 2.0ohms for primary and 11.1K ohms for the secondary. I have always heard that those can't be off by much of anything or the coil is bad. I am also running a .045 inch gap on my plugs with the coil which is supposed to be 40,000V. Is that too much gap?
Ignition system problems can easily be tested with WOT, full power runs. Trust me, it'll be obvious.
FWIW, years ago, I fixed a similar problem on a VMF'ers son's Mustang in the parking lot at Don Jose's (FFF Knott's meetup) before we went in to eat dinner. It was a vacuum leak. It was throwing the exact symptoms as you're describing.
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