MRunner

After a shop installed the timing belt on my '94 3.0L 4Runner (I didnt own it at the time) the-then owners of the Runner complained of rough idle and a miss, which it still has. It runs very rough and raspy. I have set the timing to spec although it jumps around a bit. Could the belt have been installed wrong for it to run like this?

Elton

is the check engine light on ?

ChickenLover

Possibly. The only way to be sure is to remove the timing belt cover, line the crank up to 0*, and see if the marks on the cam gears line up properly with the marks on the rear timing cover.

MRunner

It was on, code 25/Lean. I repaired a small crack in the intake hose and the CEL is off now. No change in roughness.

MRunner

So if everything wasnt properly lined up, I'd still be able to set the timing to spec like I did?

leiniesred

Yes. You are timing the ignition against the crank, not the valves. So you can get it to ignition time right. (and it will still run wrong)

The only way to check the valve timing is to pull the top timing cover. (You can leave the bottom on.)

Disconnect battery (just a good habit)
Pull the pasenger plug wires (I pull them from the distributor) Unclip the plug wires on the timing cover.
Drain the radiator down a bit (use the the petcock on the passenger bottom to get out about a gallon)
remove the top hose thing (2 nuts) remove the studs too (torx head or double nut to get 'em out)
Remove about 10 boltsfrom the cover with your 10mm socket.

You might have to take off all the belts and the fan just to get enough room. (I don't know, I don't have that idler pully (fan bracket) anymore.)

Well there ya go. Throw the timing cover in the wife's dishwasher while you work on checking the timing.

With the crank at 0 you should see marks on the cam pointed STRAIGHT UP. Now remember the crank will say 0* 2x for every cam rotation, but since yours runs, you're in luck, the cam marks will be in the ball-park. (close to straight up.) If not, turn the crank another 360. There are dimples on the metal plates behind the cams to help you line things up. Mine are painted yellow and there is yellow paint on the cams too.

If the marks are not straight up, you get to take the spring off the tensioner (talk to someone else about what to do with the newer hydraulic tensioner) loosen the bolt in the middle of the pully and push it back to the passenger side. Let the fun begin. Put a wrench on the cams and start trying to get them timed right. Keep tension on the drivers side of the stuff. Boing! what? DARN! There is valve spring tension on the passenger cam at TDC. You'll get it in a few minutes. Put tension back on the tensioner and tighten it down. Crank the crank around 2x and check your work when you're back at TDC. loosen the bolt on the tensioner and tighten it back again.

Ah good work. quality time with the Toyota. Go get the now clean timing cover from the wife's dishwasher. Stick it all back together, use new gasket goo on the water pipe thing. (My choice is Permatex ultra copper for everything) put coolant back in and get out the timing light if you messed with the driver's side cam. Battery back on, fire it up. DARN now you can't set the ignition timing because you run out of adjustment?! Well, you'll have to move the distributor a tooth now.

Set the crank at TDC. With the cap off, you should be close to #1. This is important only if you screw up stabbing the dizzy back in. Feel lucky? done this before, skip it. You know what you are doing.

Remove the hold down bolt and the cap so you can see/hold the rotor. pull the dizzy and try to turn the rotor while you pull the distributor out a little at a time, you'll clear the gears right before you pull the entire thing out. Move the rotor the right way (yeah, just think about it) and try to stab it back in the hole. This will take several tries. If you started at TDC, the rotor should be pretty close where the peg for #1 is. (the 11 o'clock peg)

Bolt it down with the distributor near the center of the adjustment. She should start right up. Set ignition timing. Go for a test drive. come back, get cleaned up and head out to dinner with the little lady in the "runs great now" Toyota.

MRunner

wow, thanks alot for the help! Im gonna tackle this in the next few days. Looks like I don't need any special tools?

I'm a little unclear on this though...

keep tension on the drivers side, like prevent it from moving while doing the passenger side?

Do I need to avoid the Boing! What do I do here?

Thanks