Hi Guys I have a 1989 GTA, I installed a new ZZ4 350 about 2 years ago. I only have about 15000 miles on the motor now. the ZZ4 motor does not have EGR passages on it, so I purchased a EGR block off plate from T.P.I.S. (since the motor had no EGR passages, I figured why have an EGR valve) The only other mods I have on this motor is I installed a Holley Adjustable Fuel Pressure regulator & gauge, and #24 accell injectors, and a Walbro 255 LPH fuel pump. I do not have headers or anything else other than I removed the catalytic converter. I have been having a pinging problem since this motor swap. I had the timing set at 10 degrees BTDC, but changed it to about 8 degrees BTDC. The pinging is slightly better, but I do notice the power loss. I mainly notice the pinging on accelaration and especially with the Air Conditioning on. I have been putting octane booster in alot, and it helps slightly. I don't want to mess anything up. How can I take care of this? I would like to bump my timing back up, and get rid of of this friggin pinging I can't seem to figure this out. Anyone else out there with a ZZ4 and the same problem? Anyone out there that can help? I know there is some Gurus out there. Thanks in advance! Take care guys!

Mike

 

You need to disable egr in the chip, the computer advances timing when it orders egr. While you or someone else is in there you may as well set the injector constant to 24. After that hook up a scantool or a laptop and watch for knock, if you see any put your timing back to 6 btdc. It may seem a little more sluggish at low rpm/light load areas but will more than likely be faster overall. The diy prom board is worth checking out.