I know this is over the top but why don't you get this engine on a scope, one channel on the coils (primary/amp clamp) and a second on the injectors(amp clamp)... or both on the same channel although that would be cluttered.
Again, monitoring the fuel trims would be a start, rather than guessing.
I am not adverse to the preventative maintenance, but if you have been using top tier fuel there would be enough detergent to keep the injectors clean...
EGR valve was my guess, only because I think I'm seeing similar problems now that you mention it. I was getting an EGR related code after my V6 Tracker rebuild, which went away, but I am noticing a slight surge.
LittleS, can you describe your surge in more detail? I started to notice a surge with steady pressure on the gas going uphill at a steady speed. Engine seems to surge up / down very slightly and only for a second or two.
Seafoam was my 1st thought too, rather than take that thing apart again... I would love to learn how to properly use a scope and advanced diagnostics but I'm not there yet.
Learning how to connect it is a big thing too. Interpreting the results is the big one, that comes with practice. I learned years ago by looking at "good" vehicles so I could understand what a "normal" waveform looks like.
Check your local tech institute, some do night classes in engine diagnostics, might be a place to start to learn how to use this stuff.
Its almost 2 months since my GV started to fail, I did a post about problems with idle and was told that it was the Camshaft position sensor, because it once pulled that code.
I replaced the camshaft position sensor and the problem still persists.
The problem is that the car idles after 20-30...
Iam trying to clean my 2003 grand vitara with 2.5 v6 engine, i have removed all the ducts and what stop me from reaching the butefly is a screen mesh, is that screen removeable? And how to clean the trottle body without removing it completely?
Thanks in advance
I just bought a 2002 Grand Vitara Limited with 140k miles for my sons first car. Very clean everything worked great for ~2k miles and then the trans quit - no reverse, D, and OD was some odd range. Trans shop pulled the pan and said direct clutch is not engaging so trans needs to come out...