P3191 Engine Does Not Start

That's an engine that has spent its life on dino oil. The deposits on the piston skirt says it all. The valve area must look like a horror show.
My guess is dealer maintained oil changes. That car has been driven hard and hung up wet.

P3191 is poor engine performance. Throttle body is first suspect and has failed or is hopelessly dirty and the butterfly is not opening. Take air cleaner off and try rotating the butterfly by the axle end of the butterfly that has a spring wound around its end so it returns to its semi closed position. Just grab that whole springed end and turn it. Its hard to turn but should open and close smoothly. Look down the TB throat with the butterfly wide open and see how bad it is. use flashlight. Check closely and make sure the butterfly is not getting stuck in its resting position. Clean the tb throat and apply spray lubricant to that spring wound end.

There will always be a little puddle of oil in the bottom of the tb. Its a by product of an Atkinson engine. Always there and means nothing. My bought new car in 07 had it and always does over 9 years of ownership. Nothing to see there move along.

Don't know why your messing with the knock sensor as it has nothing to do with your malady. There is a mechanical isuse thats preventing the engine from starting. Poor tb maintenance has been the #1 over 10 years on this site. That or you ran out of gas.

Also do yourself a favor and delete this thread and re-post it over in the Prius Maintenance and Troubleshooting forum. Not alot of people come by this forum as its more of a technical discussion forum. You need help with an engine that won't start. You'll get alot more eyes on it over there. Good Luck.

 

Maybe just doing the compression check would be a good idea. For Prius you do need Techstream or some other Toyota hybrid capable scanner (mini-vci is cheap and good) to do the compression test to do simulated cranking.

Small amount of oil in intake manifold is normal for Prius. But too much oil there or oil collecting there too fast might still tell about some problem.

Did you get some warranty for the engine reconditioning? Sorry to say this but reconditioning engine seems a bit weird to me as I would think that you could easily find cheap low mileage engine in US.

PS. Thank you for the pictures. The pictures look like the older Toyota engines where oil consumption is mostly caused by piston rings and oil drain holes getting clogged. So maybe somebody that has a Prius with some oil consumption might get it fixed by just pouring solvent into cylinders to clean piston rings and oil drain holes.

 

I doubt the installed head is correct considering the Prius engine operates on Atkinson cycle and that the engine displacement is 1.6L. It is not likely that the Classic Prius has the same head as the 2G Prius because of detail differences in the engine designs (such as valve timing, hence camshaft lobe differences would result). The combustion chamber design also may have slight differences.

It would have been much better for you to have installed a used 2G Prius engine from a salvage yard.

Did you check that the mass air flow sensor and throttle body are clean?

 

The prius classic had 8 valves the gen2 has 16 valves