Question Asked: ignition problems
March 05, 2011, 09:46 AM
I bought this truck 2 years ago and after the first fillup of regular gas "87 octane" it started pinging pretty badly so I had to use min. 91 octane to stop pinging under load. After looking down the spark plug hole I noticed alot of black stuff on top of the pistons and figured i was getting pre-ignition from all the carbon buildup. So I recently rebuilt the head and all the valves were in rough shape and some were not seating properly after my leak down test There was alot of carbon buildup, i replaced all valves , crank,cam and knock sensor was replaced, all gaskets yatta yatta. There is no instructions on how to use the crank alignment tool so I just positioned it between two teeth on the pulley, looked at the old sensor where the bolts made their mark and I beleive it is setup the exact way the old one was. It flashed up just fine with no codes, took for a road test and put regular gas in it and it was pinging even worse. I cleaned the maf sensor and no changes. I have good compression and good fuel pressure. Double platimum plugs and wires are near new. I took off the pcm and noticed some corrosion on the pins so cleaned those thoroughly with alcohol and no changes. I'm going to get a diagnostic test soon but the only issue I can think of is maybe I did not use the crank sensor alignment tool properly and the timing is too advanced. There is a gap of teeth on the crank pulley, am I supposed to use that as a setup reference? I can't find any info anywhere on how to setup? This truck has been driven about 1000 miles since the work has been done so pretty sure the pcm has re-learned after being reset.
Any help would be greatly appreciated! I drive 4000 km's a month so I don't want to kill this engine from ingition issues..