Crazy that my engine won't run.. ideas?

OK So, bit of a story.

540,000km on a 3.4L 1998 Taco 4x4 in near mint shape. All servicing always done.
I did the timing, replaced EVERYTHING, pump, idlers, seals, tensioners, the works.
Afterwards before putting anything back on, I ran it, it ran perfect. SO SMOOTH.

I put it ALL back together, rad, belts etc... and it wouldnt run. Just cranked over and over and over. It won't catch! The starter is turning the motor fine, its trying, but just consistent engine cranking with no catching.

Timing was one tooth off, so redid the belt.. same result.

Checked spark, and fuel.. both confirmed.
Compression tested the 3 easy to access cylinders with 5 seconds of crank and got about 145psi across all three... consistent is good right?

I added a 2/0 ground to the frame and a #2 ground to the block.. both direct to brand new battery terminal... positive terminal also brand new.

I cannot find ANYTHING to keep it from running. There is NO noise when turning the motor by hand on a ratched from the cams... it feels like good compression. There are no vacuum lines or electrical connections I can find missing.

The plugs and wires are brand new and the engine ran fine with them installed before doing the rest of this work.

The air intake has been put back on normally.

Why on earth isn't it catching?

 

I thought CRAP i've bent my valves or something with the timing being out, but if i had, the engine would still have started and ran like crap... hell even with timing off a bit the motor shouldn't tank.. it's non interference...
it'd run badly but still run.

it sounds like it should be some simple thing like a cam position sensor (which i never unplugged, just unbolted from the block to get the backplate off and replace the cam seals) or no ground... which i'm pretty sure I more than fixed... or the MAF..... which was FINE... and then suddenly?

 

buy a newish block add everything you replaced on this block and let it run for 300k more miles

 

Fuel, spark, and compression.

You have the spark and compression - what about fuel? Is it getting to the injectors?

 

Are you sure your on no#1 ? Anything get rotated whilst belt was off ?? Kinda sounds like it..

 

yes im getting fuel, the plugs are wet with gas when u pull them for compression testing....

not sure what you mean by on no#1... all the timing is perfectly set at TDC now, all three gears.


I looked into a new remanufactured motor.. $5,000+. rebuilds on this engine cost $3,000+. Not worth it, I'd sooner buy a new truck.

it should be something stupid.... but i cant find anything at all....

 

What I mean is that maybe you're 180 degrees out , meaning you've got gas/spark/compression all the factors in place to run except one thing...even tho' you've set everything to specs. you're out of sync. Pull no.#1 plug out bring it up to TDC & re config. your firing order

 

The 3.4 is a non-interference engine, so you most likely did not bend any valves. I just finished redoing a 3.4 in a 99 Tacoma that had a broken belt while going down the road. No damage to the valves. These engines however are VERY sensitive to valve timing. They will not run at all in many cases if you even have one tooth off.

What sounds unusual is that you said that you had it running smooth, then put it back together again and it is not starting. So I am going to go with the opinion that somewhere during the assembly process after you got it running, something messed up. If you think it may be a fuel issue, you can take a can of carb cleaner and spray a small shot into the intake behind the air filter, then crank the engine over to see if it fires. If it does, then you know it is fuel related, and can go from there.

I would not be surprised if you found something with your camshaft sensor being the issue. Spark is driven by the crankshaft sensor, and fuel is driven by the camshaft sensor. If during reassembly you bent a terminal on accident, or a wire got pinched, then no fuel will be injected.

 

Check the teeth on crank shaft sprocket unsaid you changed seal maybe broke tooth

 

im not sure what the pulling of cylinder1 plug is supposed to do.. if i take the timing belt off again and rest to TDC with all the cams and crank independent, shouldnt that be ok? im not sure how it would even allow me to install the sprockets with one of them 180 out, all the steel on steel marks lined up.

is there a test for the cam sensor? maybe i installed it out of alignment slightly?

 

The best thing to do for the cam sensor to test it is if you have a scan tool. That way you can look at the data and see what it says.

 

Well its pretty old school & may not matter with this engine, so i guess dis regard...good luck

 

i need to track down a code reader yeah.

 

so the end result was i took it into mayfield toyota.. their head mechanic was working on it on his spare time on the used truck shop side.

They busted a bolt off inside the block, and blew the timing off a few times, busted an idler that was brand new... then gave up.

It sat there for four or five months then i had it towed back to my home shop...

thinking of ripping it all out and dropping in a 4.2L 1HD-FTE