advice on purchasing correct scan tool
 

I need advice on buying a scan tool that's capable of retarding cam in 99 5.7 vortec . I've been reading through these forums for days now hoping to find a trick that fixes my problem with out' replacing everything bolted to and around it . I'm getting the "random misfire" code along with o2 sensor . My motor is running horribly .It's missing ,knocking and has no power. I've done almost everything most the other guys have and still the same thing. I know the cam has to be retarded 2 degrees but I don't have the proper scan tool to do so. I don't want to just keep spending money that I don't have on parts that don't fix the problem. Any advice on purchasing a scan tool that is capable of doing this? One other question. I have right at 200 lbs of compression on all cylinders except number 3. It has 150 . Could this be the cause of the misfire or could the misfire be the cause of the low compression in that cylinder? Thanks for your help...

Re: advice on purchasing correct scan tool
 

Reach out to Ed Wright on this forum.

Sean

Re: advice on purchasing correct scan tool
 

Misfires with O2 codes are typically linked, what I see the most is the O2 will shift either full rich or lean and induce a rich or lean misfire. Are you seeing the misfire on the same bank as the O2 codes? Does it seem like it starts running worse after it's ran for a few minutes? If so the O2 is probably skewed and once it enters closed loop it begins to alter the fuel trim which will make them run rough, any good scanner will allow you to view this data. Joe

Re: advice on purchasing correct scan tool
 

Forgot to ask exactly how were you going to retard the cam using a scan tool? I'm unaware of a variable valve 5.7 being built in those years. Maybe you're talking about backing up the cam sensor angle? If so that info also should be displayed on most any scanner, however after adjustment you need to rev the engine above 1000 RPM for it to change the reading on the scanner. Good luck Joe