A while ago I bought a 92 Montero 3.0L V6 with a wicked rod knock, but in excellent shape otherwise. I pulled the engine, did a full rebuild (thanks to the great info found on this board), got it all back together, and fired it up last night. It's running pretty well, but I can't seem to get the timing right. I've got the Chiltons manual, but it's kinda confusing as to how to get the timing set correctly.
There is a small tan barrel shaped plug on the end of a single tan wire on the firewall on the passenger side. That is the plug that needs to be grounded to set the timing, yes? And once grounded, setting the timing to 5* btdc is correct?

Apart from that, I'm digging the truck. Some small fiddling and cleaning, it's gonna be like new!

Thanks!

You may have the distributor set incorrectly. With the engine on TDC/compression stroke, the rotor should point at the center of the firewall. If that sounds strange, look under the distributor cap and you'll see why..... the tunnels move the firing order on #1 & #4 so the wires can be routed more neatly to the correct cylinder.

I'm not familiar with the '92 - the '89 has the plug for initial timing set on the driver side near the wiper motor. Maybe someone else can confirm the plug color and location.

Frank

I've got the timing close enough that it runs ok- just not exactly right. It is possible that I've got the distributor off by a tooth, but no more than that. What I'm confused by is the process of setting it correctly- the whole jumper wire/ground to fool the computer part.

Thanks!

Don't be too sure you have the distributor set correctly until you check it at TDC (compression stroke) and see where the rotor points. If it's off by a tooth, it's way off.

To set the base timing, ground the pin inside the plug to engine ground, start the engine and once fully warm, set the spark lead to 5? BTDC. Remove the ground jumper and check the active timing - it should jump to around 15? BTDC.

Frank

I think I've got it now, as close as it's gonna get. It's on the right tooth, but in the span of adjustment of the distributor, the closest I can get it (with the terminal grounded) is about 8 or 10 BTDC, which jumps to 20-25 when the terminal is disconnected from ground. The cam timing is spot on, but I'm thinking that after the heads and block were machined, everything ended up a tad off. To get the timing to 5* BTDC with the wire grounded, I'd have to machine the slot in the distributor a bit, to allow a little more adjustment.
That might be next.

Thanks for the help!

Even after resurfacing the decks and heads of a 3.0L, the distributor lock-down stud should still be near the center of the slot when the ignition lead is correctly set.

When you have the engine on TDC compression stroke, where does the rotor point?

Frank

The rotor points towards the middle of the firewall (basically), like all the descriptions indicate. one tooth either way doesn't allow enough adjustment to get it even close to the right timing. And, I can time it to within 3-5 degrees with the adjustment available. I'm not sure what else to try.

Are you sure you're on the compression stroke?

If not, remove the driver side cam sprocket cover and align the marks - or - remove the #1 spark plug and rotate the engine until you feel air coming out of the spark plug hole, then continue rotating the engine until the balancer timing mark is at "0" on the front cover.

Frank

Ya, I'm sure it's set right, compression stroke wise. I mean, the truck runs pretty darn well- maybe at about 85%. It idles smoothly, but lacks some low end power. The power comes in once the engine is spinning a bit faster- where it can actually use the advanced timing that it's getting, it's only off by 3-5 degrees- way too close to be an issue like the distributor being off a tooth or being on the wrong stroke, or the like.

OK, a last idea - you may have a spun balancer hub. If it has spun, you'll never set the ignition lead correctly.

Remove the driver side cam sprocket cover and rotate the engine to align the marks at the sprocket. Is the crankshaft mark on "0"? If not, the balancer hub has spun.... it's not terribly uncommon for it to happen.

If you find the balancer marks don't agree with the cam sprocket marks, the only way to be 100% certain where the problem lies is to remove the front cover and recheck the marks on the crankshaft sprocket and oil pump case to see if they agree with the cam sprocket marks. If not, the cam timing is off..... if they agree, the balancer has spun.

Frank