Help!!! I put a built to the hilt street 462 in my car about 3 years ago. When I installed the motor I also put a B4B Edelbrock manifold and a Holley 870 CFM Street Avenger carb on the top. Everytime that I send the car out for a power tune - learned a long time ago not to mess with stuff I don't understand - it needs a new power valve. This thing is supposed to have million or trillion mile guaranteed blow out proof power valve. 3 weeks ago it was doing the same old thing - idling very badly about 4-500 after it warmed up and also belching thick gray or black smoke and stinking to high heaven. Runs great out on the open road. Anyway, it had been in in July for it's latest tune. I had returned it a couple of times complaining that it wasn't idling right - of course it was running ok then. Anyway my friend and I decided to change the power valve. It was no big deal and the power valve looked a little funny around the diaphragm - kind a puckery. As soon as we fired it up it ran and idled great. 3 weeks and about 300 miles later it is doing and acting the same. Running very rough at idle - dying at stop lights - heavy stinky exhaust. What the F--- is up? Any ideas what to look for? Oh, one other thing it never backfires or anything untoward and always starts on the 1st or 2nd crank. Although it starts easier with a new power valve than a blown one. o No:
power valve the only way the power valve blows to my knowledge is back firing you may not be hearing it on acceleration? spectre makes an anti blow out valve, essentially a bb captured in a cage, that you can install very easily directions are on the package. as a side note a friend had an 870 on hi 455 pontiac and it never would tune right and also layed down at about 1/2 track in the 1/4 mile he tried a 780 and everything got better. my feeling is the avenger is ok unless your cam is too large the main body is plumbed differently or something good luck! :Smarty: o No:
