Low engine vacume
 

I measured engine vacume today and the gauge read 8. will a high lift cam (.572 or so ) cause this. Engine only has 4000 miles on it

That is way too low. Maybe you have mis-adjusted valves, or just a major vacuum leak.

Cams with alot of duration have lower vacuum readings, but not 8". You should be 12" or so. What does the needle do at idle? is it steady, does it bounce, does it drift? If you were to come to an unexpected panic stop, would the engine stall?

Take care,
-Chris

Its wanders a litlle bit and on a panic stop it does not stall. the air pump had been removed. The injectors are kind of old. I dont think its a major intake leak, it doesnt drive like it has 1

If it would not stall on a panic stop, then you do not have a vacuum leak, or at least not one large enough to effect the manifold vacuum at idle.

Okay then, 4 questions for you:

1) What compression pistons are you running?

2) What is your ignition timing set to?

3) Is your cam installed straight up, or did you advance/retard the cam when you installed it?

4) Have you done a compression test yet, and if so, what were the numbers?

Take care,
-Chris

Have no idea on pistons or cam advance/retard did not build the motor.

Havent done a comperssion check

and timing was 10* but reset at 12*
when its idling there is an intermitant shake to the motor

Make sure spark plug wires #5 & #6 are not touching AT ALL from the cap to the plugs, and see if that helps the miss.

Run a wet and dry compression test, dry first. Make sure you remove all 8 plugs before you start, and block open the throttle. Post your results

Take care,
-Chris

ill do the check this weekend, thanx and ill post

Just so that you know what I'm looking for, the 3 main causes of extremely low manifold vacuum, other than a leak, are retarded ignition timing, retarded valve timing, or low compression.

Take care,
-Chris