fangz

Hi its a 91 4runner V6 (3vze) auto (vzn130) .

very recent full rebuild with complete new heads , valves , guides , MLS head gaskets with copper seal spray , block was decked , acid cleaned and honned , new pistons and rings with a reground crankshaft.

Its been running so sweet up until now , heaps of power and smooth as ˟˟˟˟ , then it pulled a knock sensor code 52 , i didnt replace the KS pigtail...... i know ima ˟˟˟˟wit !

so i pull the top end of the engine down and replace the KS wire, put it all back together and its all good for another couple hours then BAZINGAAR ! i start her up and it starts to act lika pig .

starts fine and runs for about 2 seconds then the idle drops and it sounds like the engine is running on bloody 3 cylinders until it eventualy stalls unless i give it some gas , sounds like a lumpy v8 engine out the exhaust pipe

got me stumped why it starts first pop every time but straight away turns into the ˟˟˟˟in bushpig from hell .

˟˟˟˟ i have tried is -

making sure no air traped in the coooling system
no vac leaks around the intake tube from the air filter or other hoses
no oil in coolent or coolent in oil or bubbles in radiator
tried unplugging the TPS , the revs jumed up but still running ruff
held a rag near the exhaust pipe to see if it is a ˟˟˟˟ed valve.....negative


maybe i ˟˟˟˟ed up the head gasket job and now it starting to ˟˟˟˟ up?
or
i didnt put the intake manifold back on right after doing the pigtail and its leaking air ?
or
the ignition coil is ˟˟˟˟ed

Any suggestions are very welcome: bang:

vasinvictor

iTrader: (3)

I don't have much to add, but it was running good before you pulled the top end, so it's something there. Maybe just injectors aren't plugged in good? Did you get all your ground wires back on? Obviously leaking or torn gasket would wreak havoc. Or a potato in your tailpipe.

fangz

took the top end off again today and checked everything , noticed a small drizzle of oil coming out of the head gaskest on the right side head in the bock valley.....FFS !
I checked and tripple checked everything when i did the heads .

There should be no reason for this happening considering i decked the block and used brand new heads.
I thought to myself the only reason this would happen would be incorrect head bolt torque so i took my torque wrench down to the tool shop and had it checked .

well it turns out my wrench is totally ˟˟˟˟ing out of whack ! Its fairly old and has been thrown around a bit but it was something that never entered into my head when i was using it .

so im going to retorque the head bolts while i have got everything off then put it all back together , cross my fingers , pucker up my fartbox , say a few hail marrys , start her up and hope for the best.

wish me luck !

fangz

update - retorqued the head bolts but found the root cause of my problem in the throttle body gasket , the bottom of it under the TB was rooted , amazing how such a small vac leak can cause such a major problem .

If you find your truck havinf similar problems to mine then i suggest checking the intake from plenum back to the air filter , inevr would have found my problem if i didnt remove the TB and check it out .

hope i was able to help someone out there , cheers

rworegon

Nice find on the root issue. Yes, it's crazy how a tiny vacuum leak can cause all sorts of issues. Those computers want things just so to manage the engine correctly.