I used seafoam in my truck (3.0). Through the brake booster vacuum line. I did it because it was pinging a little on heavy uphill acceleration. It helped alot... now it doesn't ping nearly as much as it did before. I'm sure it will be perfect on the next application though. Man did it smoke on startup after waiting the fifteen minutes. Neighbours thought I blew a gasket <img src="/forums/images/graemlins/lol.gif" alt="" /> Anyway, it worked for my truck and depending on your problem it may work too.
AUSSiE

'88 4Runner
3.0, mod'd intake, dynomax exhaust, everything else stock.
Life will always go on....