I have a Crane PowerMax(CompuCam) 204/214, .423/.446, LSA 110 that I put in myself this last march. Since then I had a few bad problems w/ fuel pressure regulator and backfiring out the intake. Now that I have that fixed, I'm starting to notice that idle and slow off idle starts causes my car to vibrate awkwardly and will almost sound like it's trying to backfire(more when it's cold then hot). It's not THAT bad, but it's really getting annoying for how much work I've put into this. Could the reason for this be the powerband of the cam makes the vacuum too low at these RPM's? If this is the case then what are my options? Torque Converter? Maybe a 2,100 or 2,300 stall? What's one of those cost (not the most expensive one)?

Thanks for any help that's given,
Kyle

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1985 Blue Camaro Iroc-Z28 LB9 305 TPI 700R4 (3.23)
Crane PowerMax(CompuCam) 204/214, .423/.446, LSA 110, summit double roller, !AIR gone, chopped air boxes, K&N's, airfoil, !MAF screens, NGK plugs, Hypertech thrown away, shift kit, highflow cat, flowmaster 80 series, poly's all around, great sound system

1/4 mile w/ a messed up fuel pressure regulator: 15.40 @ 89.44mph
Might be up for sale.

 

Not likely. That's a very mild cam that I have personally used. As I recall I had it in a smogger 305 (carbureted) with the usual bolt-on goodies and pulled about 16" of vacuum- plenty of vacuum. TPI engines don't really like tight LSA on the cam, but that one's so mild there's almost no overlap, despite the tighter 110* LSA angle. I'd look elsewhere.

 

hmmmm.....thanks,
could a bad plug wire or two cause this kind of a problem? or maybe something in the distributor(i've had the ignition module already checked at autozone and they said it was fine)?
thanks,
Kyle

 

What is your vacuum reading? I get 16 psi. I have 219 deg duration Int/Exh, 0.525 lift and 112 deg lob sep.