i have '86 iroc 305 tpi ran 10.5 stock. With summit cam ran 9.7 put hooker headers and daul hooker mufflers with no cats and adustable fuelpressure regulater best time 9.4 but runs consistant 9.68 what am i doing wrong? Also when i shut the car off the fuel pressure drops rapidly to 0. any ideas???????

 

Whats the specs on your cam? Did you do anything to your heads?

Whats your timing set at? Any o2 or scantool readings?

 

TUNE UP TIME!!!

 

If your fuel pressure drops super quickly you might be looking at leaky injectors, in which case maybe you're to rich, thusly contributing to your poor times.

 

Your times don't seem that bad, there are a load of 305 thirdgens that run at the local 1/8 with more mods than you and can only hit 9.2's and some 9.0's. The best I have seen is the guy with cam and NOS running an 8.8x. Granted there is a prob with the fuel pressure drop though!

 

the cam specs are a lift of .420/.442 and a duration of .204/.214. i dont think it is running too rich because check engine light came on for running too lean so i adjusted fuel pressure up 7psi. no i hane nothing done to the heads. the cam took off .8 but the whole exhuast took off .1 that doesnt sound right to me. it is the stock distributor and cheap wires. timing is at 9 degrees stock is supposed to be at 6 degrees

 

I think that cam is crap to be honest with you. I'd have gone with something much more radical..

My fuel pressure drops pretty quick as well..

-- Joe

 

If your fuel pressure drops from 45 to 15 psi in ten minutes, that's acceptable. If it drops from 45 to zero in one minute, something is wrong.

 

ck valve in pump is leaking,if it was injectors bleeding down that quick you would be having hot start flooding problems.