ADHDYota

OK I hope someone else came across this and can help me solve it.

I have a 3.4L 98 Tacoma... It has 540,000km on it and runs like new. The whole truck is as near mint as you can get at that mileage.

I did a timing belt and water pump replacement (on schedule, 95,000km after last one was done) and the motor will not start.

I managed to get the timing belt on ONE TOOTH to the left of TDC. With nothing else hooked up I mounted the crank pulley and started the motor, it ran smoother than I've ever heard one run before. Very nice.

I reassembled everything else, and the engine would not start. It just tries... but doesnt catch.

It has confirmed spark, confirmed fuel in the cylinders, the ground is awesome as i added a 2/0 ground cable to the frame.

There was a cam position sensor on the passenger cam which had to be removed to get the plate off to do cam seals but I did not disconnect it, just moved it for a minute and bolted it back on.

I can't find any electrical connection or vacuum connection that isn't back to normal.

When you turn the key it goes WRRR WRR WRR WRR WRRR like the starter is cranking the engine along valiantly but no catching. No stumbling either, the sound is perfectly uniform.

The engine appears to have compression, turning it by hand yields the usual stiff resistance followed by quick jump. I'm buying a compression tester tomorrow to confirm.

Some people think I bent some valves and wrecked the head, but the motor would still have run and made awful noises... this wont even catch, it's as though there's a sensor screwy or the ECU isn't happy?


Please tell me you know about this and I havent screwed my heads.

Any further details?

ADHDYota

oh PS, the timing belt was re-done to be properly TDC.. all the bearings and tensioners were replaced as well.

man what a pain in the ass to get that AC pump removed to access the bracket you have to pull out to replace the hydraulic tensioner. no wonder people skip that part.

thekeith86

could not have bent valves. it's a non interference motor. you can have complete backwards timing and not have any valve slap. with that said your valves are still good. i've done my timing before when i pulled my head off. when i pulled the exhaust cam off i forgot to put a 10mm bolt in the cam gear. so the cam side was off a tooth. just ran a little rough. do you have spark??? pull some plugs and test them on a paintless bolt with the plug still in the boot.

thefishguy77

iTrader: (1)

When you spin it over is the starter not catching the flywheel? Wrr wrrr sound? Maybe for some reason the starter solenoid might be out? Don't know crap about this motor but first thing that stood out
Good luck

wyoming9

iTrader: (1)

You might want to think about moving your ground to the engine block.

You could just add another and run to the block.

You also might want to double check the ground for the ECM on the left side of the intake.

remember to plug in the Maf sensor ??

Have the air intake on tight??

The battery is fully charged??

Gotta be something simple:jessica::jessica:

1blink

So the engine cranks with the starter, but does not fire up, right?
Check for a missing tooth on the crank timing gear.

ADHDYota

OK so, thank you very much for the help with the motor type.

Yes there is spark. The MAF sensor is in, and the intake is on fairly tight. I will tighten it down 100%...
I'll add another ground to the block, do a compression test.. and see where I'm at.

It's definitely a WRRRR WRRRRR WRRRR sound not a catching/stumbling sound... as though the starter is spinning the motor but nothing is happening.

The starter is definitely catching the flywheel, its rotating the engine....

ADHDYota

three cylinders compression tested read just shy of 150psi (all consistent) but i dont know if i did it right. I didnt pull the fuel pump fuse and i let it crank for 5 seconds per cylinder.

i added a #2 ground cable to the engine block, which complements the 2/0 ground cable to the frame, both direct from negative battery terminal.

still nodice

wyoming9

iTrader: (1)

you did not run out of gas by chance??

If you have spark it can only be fuel or timing .

Are all the sensors plugged in.

you had it running ran fine

just what did you put back together??

It should have only been the upper cover

Some time while buttoning this up you screwed*** something up .

Have you checked that no fuses are blown or something is unplugged electrical connector not fully seated

ADHDYota

great questions..
all sensors are plugged in, though is it possible I may have bolted the cam sensor back on incorrectly somehow? it seemed to only fit in the one spot but theyre sensitive right...

i put it all back together, that means lower cover, upper cover, the back plates which get removed to do the cam seals, all the hoses and lines, the radiator reinstalled, all the pulleys and belts etc..

No blown fuses.
Now its all open again

Rad is out.. belts all off. covers off, back to the timing belt exposed top and bottom... cant find anything wrong.

1blink

Have you checked a cylinder from each coil pack for spark?

While you have the covers off, turn the crank by hand and look at each tooth on the crank timing wheel slowly, 1 at a time. A broken tooth could give you this problem.

Also, try starting her with the MAF crank and cam sensors disconnected.

1blink

Did you sort out the problem?