Been going at this green turd for quite some time now and still have not figured it out.
For starters:
99 4runner Limited v-6
173k miles
Tune up last year
Ignition coils 3 weeks ago
Cleaned MAF and entire TB twice
Replaced PVC and grommet
No CEL's
Head gasket leaks tested through radiator and none found.
Originally the truck was starting with a rough 20-30 second idle that shook it like a tractor. It smoothed out and idled normally afterwards. I get a pretty big smoke show when it happens. The truck would feel like it is randomly missing when going up a hill around 3k rpms. It kinda felt like it was bucking and this made it hard to keep speed or accelerate. There will be a good 2-3 seconds before the truck would shut off as well. I had oil leaks coming from the valve cover (all around), oil pan, and oil fill cap. Oil was leaking into the throttle body as well.
I was hinted that the PVC could be causing the issue so i ordered a Toyota PVC and swapped out my old one. The old one still rattled but was caked up pretty good. Over the next few days the symptoms slowly disappeared. The rough start was reduced down to 2-3 seconds. The misfire under load was gone. The shut down delay stopped and it would shut down immediately when you turned the key off. Start up smoke show was still there though but not as heavy. I thought I was good to go until the 20 second rough start and miss under load returned two days ago but no sign of it yesterday. Now.....wtf.
I am guessing that pvc clogged up already but doubting that.
Any ideas appreciated. I am at my wits end with this truck and about to get rid of it unless I can fix it. Two shops have had it and both were unable to figure it out. One shop recommended coils and injectors. Coils replaced but injectors on hold till i rob a bank.