I know this is going to sound stupid but. i have a 98 4.3 CSFI i just changed the motor anyway. i have an issue that is making mevery angry. the timing on the truck is suppose to be -1 or 0 and you are saying to your self thats crap you cant set the time cause its a fixed distributor and the computer does the rest. i set the distrib i tooth forward and one back no run. just backfire sounds like its 180 off not the case. truck runs great but the snap-on scanner and all other say its 12 degrees advanced??? it makes no sense to me unless the cam sensor or crank sensor is f ed up. ever run into an issue like this? cause when you nail it it good intill the high rpms in wich i belive the knock sensor is taking over?? i am lost but i need to get the timing to 0 or -1 where it needs to be please help!

 

Timing is never straight up... I thought I had an excel spreadsheet in my Google Docs from my last few scans of my Bravada, but you will never see 0 timing on these motors. No motor that I have ever timed was set to zero advance...