Hi All,
Thanks in advance for your assistance. We picked up a "running when I parked it" '91 4 Runner with the 3VZ engine and manual transmission. Apparently it was taken apart by an optimistic high schooler who wanted to add a turbo. About a thousand vacuum lines, all the belts and the pulleys along with a replacement water pump, the plenum and the A/C compressor were in the back. He also disconnected the clutch for some strange reason?!
We re-assembled everything minus the A/C and she turned over but wouldn't fire. In the midst of troubleshooting, my husband Matt disconnected the coil, inadvertently laid the connector against the brake master cylinder and cranked. So, high voltage through the master cylinder (and whatever else) didn't make it work any better. Post our ECT efforts there was no cranking, no dash lights, no brake lights - we figured she was dead. In the interests of giving her a fighting chance (and saving face a bit) we tried a few things. Not sure whether this is even remotely important, but when you turned the key, nothing happened. When you put your foot on the brake and turned the key, the check engine light and a couple of other lights came on on the dash. We replaced the ECM and it made no difference. We replaced the master fuse/fusible link and checked/reset all the circuit breakers we could find along with all the fuses: No change. As a last resort, we tried adding a ground to the negative battery terminal and things started working again! We finally got her to crank after disconnecting the alternator (figured maybe it was dumping current). So now we're back to square one (or minus one maybe?). After fiddling with the timing and rechecking the position of everything vs TDC the engine will run but the timing belt is jumping teeth. We figured the tensioner spring was shot, so replaced that with a much heavier one we had kicking around. The belt is STILL skipping (loose between the cam pulleys/idler).
So here are my questions:
What have we cooked and what should we check/replace in order to get rid of the makeshift ground attached to the battery?
Why the heck is the timing belt slipping and how can we fix that?

Matt is sick of messing around and ready to roll her out in the yard with a "For Sale" sign and call it good.
I'm still looking forward to making her my daily driver/fun rig.
Any insight would be very much appreciated,
Lucy

 

Hi:
You have to figure out the timing belt issue for your first effort.
That belt should be tight as crazy around the left cam pulley, under the idler, and over the right cam pulley.
Is the belt a new one that you purchased, or was it part of the "stash" in the back of the car?
If so it may be stretched, or even the wrong one.
The spring for the tension device should be very robust. It should be a bitch to install.
A spring that you had laying around ain't gonna cut it.
Buy a new OEM belt and tension device from the dealer, install it, take a picture of the installation, and post it in this thread.
The forum people that will help you, love to see photos of of what you are talking about.
Art.

 

There is a good chance you have the wrong belt. All so the tension spring is meant to tighten the slack out of the belt but you have to tightten down the bolt on the tensioner. It’s not a active tensioner.

 

Doh! First time we've heard about there being a bolt - that makes perfect sense given the arced slot....
Thanks a lot!

 

Hi:
Good call on the tensioner.
All of my experience with the V6 engine has been with the hydraulic device.
This why I love to hang around this forum, I learn something everyday
Art.

 

Hey Art,
Appreciate your response too. First thing I did after reading it was check the belt packaging to make sure it was bonafide.
We run a hotrod shop but never owned/worked on a Toyota before. If we'd taken the original apart, putting it back together would have been easier; this has definitely been a challenge!
Looking forward to using this forum and taking advantage of everyone's experience.
I'll post some pictures - hopefully we'll have her running tonight!
Lucy