Since I've rebuilt the 3.0 in my 92, I've been chasing around a couple bugs that I can't seem to figure out. I've gotten all the "not quite tight enough hose clamp" kind of things fixed but I continue to have 2 issues that are probably related, but I can't seem to solve.
The engine starts and runs smoothly, but seems quite low on power. It drives around town (flat) fine, but without much "punch". The power it does make is pretty even and smooth, no surging or flat spots, but it just seems weak.
No CELs or anything, starts the same warm and cold, etc.

The other issue is the timing. I can't get it timed to where I want it. Currently it is timed (with plug grounded) to about 10-15 BTDC. The distributor is maxed out in it's travel to get it to that point. I can't turn the distributor any further to get it to the correct timing. I've tried moving the distributor a tooth to try to get there, but I end up with the same problem on the other end of the scale, ie: it maxes out the travel on the slot of the distributor before it gets to the correct timing.
When I'm trying to time it, it seems like the timing jumps around a few degrees constantly as I'm looking at it.

I've disassembled the front of the engine a couple of times to confirm that the cam timing marks all are correct, and they are. And, it doesn't seem that the damper has spun, as the timing marks on the timing cover line up correctly after re-assembling the front of the engine.

I've done all the other things I can think of to figure it out, all the maintenance you can do is done (filters, O2 sensor, etc.)
I'm currently getting about 17mpg around town, which seems ok turning the 31's.

Can a failing ECM cause these problems? Low power and wacky timing?
I've been looking around for someone local with a 92-94 so I can do a quick ECM swap, but so far can't find one.

Thanks in advance for any comments or advice

Brian

That seems like a problem I was encountering with my 91 I rebuilt. The ECM was reconditioned by a guy in Florida. Pretty good guys with lifetime warranty on the repair. I never figured out what the problem was but I'm tempted to rule out the ECM. However if you still want to troubleshoot with another ECM, there are a couple of yards in the Denver and Aurora area that always have Monteros. They list the "computer brains" at $30 a pop. Good luck!

I don't think it's the ecu.

The correct timing is 5*btdc with the brown connector set the timing wire grounded. Both the 12v and 24v 3.0 have the terminal on the big harness on the firewall, 24v on the pside IIRC, 12v on the dside. 15* is way too much advance. This much will kill power down low. I think you have a det sensor on that engine, and that may be retarding spark which will also kill power and economy.

Make sure you are grounding the right terminal and reset the timing to 5* and see what happens. If you are seeing variation in the timing with the connector grounded, either you have a bad dizzy/crank position sensor, or you are grounding the wrong terminal. After correct setting, you should see around 15* and it will jump around, and may vary 7* or so, with the timing connector ungrounded...

Both the ECM and the distributor module could be suspects.

Frank

I'm definitely grounding the correct terminal- the large tan single wire plug on the passenger side firewall. It works correctly (it retards the timing about 10* when grounded). The 10-15* I'm getting is with the plug grounded- so it is at about 20-25 when ungrounded, obviously a problem.
There is no way (physically) to move the distributor to 5*.

As far as I know, there is no knock sensor on this engine. I certainly never came across one in the rebuild process, unless it is a variety that I am unfamiliar with.

Frank- when you say the distributor module, do you mean the power module thing that is mounted next to the coil?

Thanks

Doodlebug the dizzy in the hole some more. I think you missed a tooth on the reposition. If the cam timing is correct, and it may still not be, you should be able to do a basic mechanical dizzy timing.

No, that's the power transistor. I mean the optical module inside the distributor that reads the crank position through the slotted wheel - it turns with the distributor shaft off the camshaft.

I am in agreement with Eddy.... it still seems possible that the distributor is not set correctly. Can you set the engine on TDC and take a picture of the distributor rotor and post it here?

Frank

The 24V has coil packs. So no timing to set, right?

Here's a pic of the rotor. It's pointing towards the center of the firewall, as I've read is correct. The engine is at TDC. The distributor body is turned as far as it can go counterclockwise, which is the only way to get it to the current timing, as mentioned above. To get to 5* BTDC with the plug grounded, I'd need to turn the distributor further CCW, but that is not possible. I've moved the dist. one tooth in both directions, and can't get any closer than it is now.

The distributor is set correctly if you're on the compression stroke. I'd look for a friend with the same year model and see if you can swap distributors and ECUs - one at a time - and see what happens.

The only other thing I would suggest is to reinstall the distributor cap and take another picture. On this picture, tell us which wire goes to which cylinder. Just humor us on this so we can make certain the wires are installed correctly.

Frank