One other check to make if you haven't already... set the engine to TDC (based on the crankshaft pulley lined up with 0 deg. BTDC and the position of your rotor as shown in your photo) and pull the drivers-side camshaft pulley cover and verify that the timing mark on the pulley lines up with the mark on the housing. I suspect your timing belt may have jumped a tooth. It would be good to also check the camshaft pulley/cover mark on the passenger side, but that's a little more involved.

I say all this because your symptoms sound very much like what I was seeing when my timing belt jumped a tooth during my valve stem seal replacement last year and I didn't realize it right away.

Good luck! <img src="/forums/images/graemlins/kewl.gif" alt="" />

Eric W.

I'm thinking the same. Very easy to get off one cam tooth when wrapping the belt. This would put the dizzy in the condition you have.

It does sound like the cam timing could be off, yet:



Weirdness.

Frank

Would a bad, failing or out of adjustment throttle position sensor cause this? <img src="/forums/images/graemlins/ignore.gif" alt="" />

I wouldn't think so.

Frank

I can't tell you how many times I've taken it apart to check all the timing marks. I'm on the hunt now for a truck that I can swap some parts across to check. I found another 92 that a local shop was trying to sell with a bad knock, but when I asked if I could "rent" the ECM for a few minutes the guy was a total A$$ about it.
Anyone in northern Colorado with a 92-94?

Brian

I'm in Brighton. I'm not at home but I think I have an extra distributor and throttle position sensors, for testings sake. Might be tempted to let you try the ECM. It's a reconditioned unit that I haven't tested yet since I'm still building the engine.

What about the dizzy gear? Is the roll pin sheared? I've got to say I've put a 3.0 together VERY carefully, and still got the cam one tooth off. I'd recheck it all again, taking nothing for granted. Things like cam dowel pins, crank pulley key, slippance of the pulley marks from broken damper rubber, swapped cams, you name it. I find it useful to forget that I put it together, to keep ego from getting in the way of discovery, and I pretend I'm trying to find out what that stupid mechanic messed up...

There's a mechanical timing problem somewhere, you just have to find it.

Fixed!

Damn spiders!
I disassembled the distributor to check out the cam and crank position sensors within. What I discovered was a nice assembly of dust and those tightly woven spider webs covering some of the guts of the distributor.
I cleaned it all out and re-assembled it, and POOF! it times right up and runs perfectly. I guess the optics of the sensors were being partially blocked by the junk, keeping it from working correctly.
I'm not even sure how a spider got in there. It all seems pretty closed up and well sealed.
Anyway, many thanks to all, your advice led me to where the problem was.

Great! I like a man with persistence...

Sounds like the fine grain sensor/led was blocked, leaving only the coarse sensor working. That should cause the inability to get the timing right.