Ive got an 85 765 with the B230FT. I am quite aware of the catastrophic faliure of these engines (throwing rods and what not) and i drive it pretty hard. It runs the stock 8 lbs of boost, has an IPD VX cam, and has had only one valve job done 25,000 miles ago. Since i got the car Ive had intermittent pinging problems. Ususlly over 3500 RPM and a heavy load sometimes worse than others. Ive replaced the injectors (which gave me nice results, but didnt cure the pings), I put in a new knock sensor, and torqued it to 15 ft.lbs. the timing i have set to 10 deg BTDC. I had it on an emissions scope today and the emisions were nice and clean, but i could not adjust the air mass meter according to specs by unplugging the O2 sensor, it would go leaner but I could not get it to really richen up. I have an air fuel guage and it shows a nice rich mixture under heavy load, i run the great california 91 octane premium gas (octane boost does not really help too much)The inside of the cumbustion chamber is clean and its not overheating. HELP!!! im out of ideas at this point besides a possibly bad ignition control module(the one under the dash) There is a new harmonic balancer so im pretty sure the timing is correct. Im going to try retarding the timing to 7 or 8 deg BTDC tomarrow see if it goes away. Has anyone had this problem, if so WHAT FIXED IT!!! Im going to end up blowing this motor eventually at this rate and i really dont want to (at least not untill i have another waiting to go in)
Mark