My 95 4runner had the infamous blown #6 head gasket. I pulled everything off replaced both gaskets with MLS gaskets and pulled the EGR. Got it back together and she ran as well as can be expected for the 3.0 haha but really she ran great for three weeks (spark, fuel, air). Last week I parked her went out of town and now it won't start. Turns over fine, checked for spark at the coil then plugs, bypassed the MAF, checked/doublecheck mechanical timing, can smell gas/wet plugs, cleaned the plugs rinse and repeat. I've come to the end of what I can think of less starting to dig into the engine. Looking for a second pair of eyes. I don't know why it would run fine and then not.

 

mine does the same thing, rebuilt less the 5k miles ago, full board for the rebuild. girlfriend took it to her aunts house and it randomly shut off on her. and wouldnt turn back on. now if we wait a day or so itll turn on and run as long as we hold the rpms up. it runs like crap for the first couple seconds bu then it clears right back up. but if we let it go back to idle, it will die instantly and will not restart. and if we keep cranking we smell fuel and can see it dripping out of the exhaust.

were you ever able to figure out your issue?

 

Could it be the ignitor, and/or coil, getting hot, and going out of spec as far their resistances? If they go even a small amount out of spec, it can make them cease producing spark as they should. Hence, wet plugs, fuel smell, no start, cranks ok, and starts OK after sitting for a while. The ignitor and coil cool down, and go back into spec, so they work fine again.

If you want to test them hot, you can use a heat gun, not a paint stripper type, an electronics use type, to get them warmed up to where they are, roughly, after running for a while, so you can check them. The FSM has the normal readings in it. If they go very much out of "normal" they're bad, and need to be replaced.

Hope this is a small help, or leads to the actual trouble.
Good luck!
Pat☺

 

Mmc if yours starts at all you're already a step ahead of me. Do you have a check engine? If so maybe you can get a reader on it and see what codes you pull. If you have a bad knock sensor/sensor wire the ecu will think that you've got an issue and will run the fuel/air super rich when you don't need it which might cause some of the symptoms that you have (rough low rpms/no idle). Mine was giving me a check engine light after running for a bit and getting up to temp but no check engine until then so until I can get it started it won't throw a code. That might have been my problem but I assumed it was egr related bc I lost the resistor that tricked the ecu. I'll give a fresh ignition coil and plugs to see if the coil might be the issue. At $30 it could probably use a new coil anyways. I'm going to have a bit of time on Friday to keep troubleshooting. I'll keep this thread up to date on what I've troubleshot and when I figure out the issue.