pinging/detonation

[84hotairgn]

hello,i just joined the site and recently picked up an 84 hot air gn.previous owner says engine and trans were rebuilt 6k ago.test drove the car and it seemed ok.filled up with 91 on the way home.noticed that under heavy accel i can hear pinging/detonation followed by a pop and boost falls off.and car basically goes no were. up to 5lbs of boost easy accel car seems to run ok.alittle shaky at idle.i called previous owner and he said to put the straight pipe back on,cold air,adjustable regulator set at 42pis that he took off for smog and recheck. seems worse.modifications include cold air,adj waste gate,boost gauge,headers,hooker cat back,poston 91 chip,3olb injectors,307 walbro fuel pump, heated o2s,i have an otc scan tool im going to check some data list items.my first turbo car. kinda in the dark.any help would be appreciated.oh yeah any other mods i should think about and were to find them?ecm,map,maf etc. etc.thanks. evry one i talked to told me to by an 87 intercooled but i like to be different.does any one have pics of cold air installed?i dont know what brand this one is but seems to fit a little hoaky.

 

[1 in 2000]

I'd start by checking all your vac. lines, and go thru the spring cleaning checklist since the car is new to you.