Ok... So I have a 1990 Toyota 4Runner SR5 with the 3VZ-E. When I bought the vehicle, it was a non-runner. The previous owner stated that it was blown head gaskets. I took the vehicle home and pulled the heads off and found that the spark plugs had been left out of it and some minor surface rust had formed in the cylinders. I went ahead and purchased a full gasket set, rings, bearings... etc. I had the heads machined by a local machine shop and I honed the cylinders myself. I installed the rings and bearings and got the engine completely put back together and dropped back in. When I initially tried to fire it, It cranked fine but wouldn't fire. A quick check determined that the fuel pump was bad. Turns out the vehicle had sat so long that the fuel in the pump turned to varnish and gummed up the pump so bad it wouldn't turn. I replaced the pump, drained the tank, blew out the lines, filled it with fresh fuel and tried it again. No luck. I'm getting good strong spark on all six cylinders. Cam and ignition timing is set correctly. I hooked a noid light to each injector harness and determined that they are all functioning. No CEL trouble codes. I reasoned that the injectors may also be gummed up since the pump was, so I replaced the injectors. Still no luck. It's definately getting fuel to the injectors and they are firing. I can now smell fuel coming from the exhaust. It cranks fine and as it cranks, I can hear an occaisonal puff which sounds like the engine trying fire, but it won't catch. If I crank on it for more than 30 seconds or so, it will sometimes backfire a bit, which sounds really bad. It pushes the backfire back up to the MAF and slams it shut, producing a loud "whack" sound. Obviously this is just a small symptom of a more major problem, but worth mentioning. And that's it. I've put a lot of time and money into this stupid thing and it still won't run. Any thoughts?

 

Oh yeah, and I did replace the fuel filter as well.

 

sounds like you did a lot of work for naught. fuel pump tested bad... replaced... didn't help... fuel was varnished, drained and replaced, didn't help.
maybe the valve adjustments weren't done properly after having the head work done?
a quick check would've told you that... even before you had a problem with the fuel pump.

 

common sense tells you- rebuild engine
check cam, check valve adjustments
check distributor
try to start.

 

The valves aren't adjustable.

 

whelp...
either
... you don't know your engine...
or you don't your engine.

pick

 

the 3vze is a cam-over-bucket configuration with shims inserted between the cam lobe and the bucket follower on top of the valve in order to adjust the valves.

learn... please.

 

if you honestly did not know that, I won't hold it against you

 

Well your know it all sarcasm isn't appreciated and I'd really like to know how you would adjust valves on an overhead cam motor with cup-type cam followers. Any pointers on that?

 

Actually there are shims under the valve spring itself. That all checked out on engine assembly.

 

all sarcasm aside....

a feeler gauge between the lobe and the bucket to determine the clearance
remove the shim that is already there, mic the shim and compare to what the clearance should be and what was measured
install a shim of the proper thickness.
if there isn't a shim, install one to facilitate what the clearance should be.

 

That has already been done. Besides which, even if they were slightly out of adjustment, it would still run. I have good compression, fuel, ignition, and timing. What else would it be?

 

agreed... a few thousandths in the valves should not keep the engine from starting.
what I would do next is verify that when the crank is at TDC, the #1 cylinders valves are also loose, and verify that the distributor rotor is pointing directly at the #1 cylinder's spark plug wire on the distributor cap.

 

Already done that about half a dozen times. And it is on the compression stroke. I've checked that numerous times. Same with the cam timing. I've gone back and double checked it. Everything is lined up perfectly.

 

you've ran a full compression check?
what were the per-cylinder results?

 

Honestly I don't remember the exact numbers, it was about two weeks ago, but I think I recall around 120 pretty much across the board give or take 10. Good enough that it should run.

 

given what I read above, it sounds like the ignition timing is out.

 

The rings obviously haven't had a chance to break in yet, so I would expect the numbers to be higher once it actually runs.

 

should be more like 160-180.

 

I welcome anyone to help.
DeathCougar, et al.