I'm helping out a friend with a non starting '88. That's LH 2.2 and I am much more familiar with 2.4 which does not have a Hall sensor.

The background is that it cranks, and occasianally seems to barely fire with a little black smoke coming out when it does. Old plugs looked somewhat fouled with soot, put in new ones. Has fuel and at least intermittent spark. Tried swapping fuel pump relay and coil, didn't think they were the problem, but it was easy and spares were available. I have a spare ECU and fuel pressure regulator I could try, but these ECUs are supposed to be reliable and there is no fuel in the vacuum hose from the current regulator.

But then I looked at some recent posts about Hall sensors. When I crank this car the tach does not move at all (though the speedometer does jump initially). Is this a definite indicator that the hall sensor is bad or not properly connected? Do the other symptoms fit with that? I need to go back and check the wiring to that sensor and hope that is the problem.

So I checked the FAQ for replacing the Hall sensor, but of course, that describes it on the 740, which has the distributor in a different place. If I do determine that the Hall sensor is bad, it seems like swapping in a whole new distributor from the pic-n-pull would be the easiest way. On the 240, is distibutor replacement a fairly easy job? Any tricks I need to know? The FAQ describes marking the orientation of the distributor when you are putting the same one back in, but if I am putting a different one, how do I orient the replacement properly so the timing is right?
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Andy in St. Paul, '91 745 Regina 198K mi, '89 244 142K, '87 245 RIP

In addition to Rob's tips, here is my response to—

The FAQ describes marking the orientation of the distributor when you are putting the same one back in, but if I am putting a different one, how do I orient the replacement properly so the timing is right?

With crank at cam at 0° TDC for #1 piston, the dist rotor should be about 1/4" to 5/16" past (i.e., to the right of) the 0° tic mark on the distributor body. This will be close to the nominal 12±2° advanced timing position.
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Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.

Dist replacement is not hard except for one thing: these little buggers get stuck in the block. The dist doesn't want to turn or come out or move at all on a lot of 240s.
That said, if it can turn easily for adjusting timing, then it will come out. There's only a single bolt (13mm head) holding it in, just behind it.

It *could* be the distributor, and sounds that way from what you describe. However, check that you've got 12V at the coil. If not it might indicate a bad ignition switch, or possibly a problem with the connector in this picture:
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Rob Bareiss, New London CT ::: Roterande Fläkt Och Drivremmar!