Grimmy

To Start i bought a 93 3.0 4X4 for my daughters first truck.. i bought it knowing it had a dead cylinder by the way it was running. I did compression test and #5 was 000. pulled the heads had them rebuilt and surfaced. 6 new exhaust valves. i installed them adjusted the valves and have good even compression in all 6 cylinders. it starts and runs good but under load i have no acceleration it wont go up a hill when you get into the throttle it just boogs. i have took the timing belt back apart (3 times) and it seems to be off a tooth on the crank every time. i bought another new timing belt (gates) and installed it now i cant get it to time to 10 degrees the distributor doesn't get close enough switching teeth to time it and still have the same power problem. it had more power with the dead hole than now running on 6......

Anyone ever had the same?
am i right to set the crank timing a tooth forward and run it?
am i going in the wrong direction and should try some thing else?
its not throwing any codes...

scope103

Welcome to YotaTech. It's not TOO hard to get the valve timing off by a tooth, but it has nothing to do with the belt. If your valve timing is off (that's what "off a tooth on the crank" means) you'll have even compression but severe loss of power. You should be able to set the crank to TDC and have both cam sprockets with the arrows pointing straight up. If not, start over.

It is pretty easy to get the distributor off by one tooth, which moves the ignition timing about 23°. The gear on the distributor is helical, so you have to put it in matching the marks, and the distributor will then twist into the correct position from which to set the timing.

Andrew Parker

Pull the pins from the cam sprockets and loosely replace the bolts. Set the mark's and rotate the belt through two full revolutions and see how the mark's align. If all is good and lines up with the tension set rotate with bolts removed and replace the dowel pins into the cams, torque bolts and your done. The 3VZ-E is a non interfearence engine.

My 3VZ-E runs like crap at 10 degrees. It is much happier at 14 degrees. The harmonic balancer pulley is decoupled by rubber to add compliance to things and my wonder is that the pulley and the nick in the edge that you set timming with is perhaps drifting a bit given enough time and mileage on the engine. Try the 14 degrees and report back.

Tims86Toy

From my own frustrations with timing on my '86 carburetor version, if the distributor timing was off even one tooth it would not even crank. Compared to an old small block chevy these motors are very picky about timing. One of the reasons I suspect is the limited range of adjustment on the distributor. Even though yours is an ECU motor you can still use an old school induction timing light and watch how much your ECU is advancing timing. Too high and it runs like crap and overheats, Too low and it backfires or doesn't run at all.