89 Toyota 4wd ext cab 22RE 135k 31's 4.10 gears
Ive owned the truck for about 2 years now, ever since ive had it, it has always spark knocked under hard acceleration. Ive tried various fuel additives, new plugs, throttle body cleaner etc. Timing was @ 5btdc with te1 and e1 bridged. I always use 87 octane, but when i did use 93 octane once, it didnt spark knock. Looking at the spark plugs there is evidence that the fuel mixture is lean. So today i experimented with retarding the timing, I had to retard it to 2btdc(te1 &e1 bridged) before the spark knock almost stopped. It is hard to tell but engine performance seems to be the same. The previous owner did have a dual row timing chain kit installed with an adjustable cam gear from LC Engineering, ive experimented with the cam gear also, still no luck. Any ideas on what is going on? Thanks for your help in advance.