need detonation help

[TurboLegacy]

does anyone know what parts could be bad that would cause detonation? i recently installed a walbro 255. my stock pump started dying on me and it seemed that the engine was getting too much air and too little fuel so it would detonate. now it seems i get too much fuel. i thought it had to do with the morgie fuel cut or the manual boost controller so i took both out and put new hose on. my engine pulls as it should if i floor it above 4000 rpm. if it is underload it starts to do that horrible detonation popping. from a dead stop, it pulls ok under 1/4 throttle, but will detonate if i give it anymore. could i have a bad fuel pressure regulator? could it still be getting too much air? thanks for any help

[evolutionmovement]

Could be plugs or other internal combustion chamber problems - anything that could cause a hot spot.

Steve

[douglas vincent]

Or gas, you ARE running premium I hope.

Personally, I HAVE to run 94-95 octane or I get the damn knocking, but then again, I am special.