[Rickus]

I believe I finally got the alternator wired in with the new harness and tried to drive the LUV truck. I was getting around 12.9 volts and after three or so minutes on the road the engine started running really bad. I managed to limp home and with a timing light I can see the timing mark jumping around quite a bit. That's when I can actually get it running now. With a timing light attached and cranking it over, sometimes I get constant firing and sometimes not. So it is intermittent at best. Now I have changed the points (checked the gap several times) and condenser, changed the coil, and to remove the voltage/alternator from the equation, ran a wire straight from the battery to the positive side of the coil, where I get the same results. My conclusion is the distributor is bad in some way. Before I get a new electronic distributor, I would like to ask if anyone has an opinion on a possible problem I have overlooked? Trying not to spend too much money on this thing as I have another engine on the side (V8 thanks to my nephew) to drop in come December and just need this engine to run until then.

[cobalt327]

Originally Posted by Rickus

I believe I finally got the alternator wired in with the new harness and tried to drive the LUV truck. I was getting around 12.9 volts and after three or so minutes on the road the engine started running really bad. I managed to limp home and with a timing light I can see the timing mark jumping around quite a bit. That's when I can actually get it running now. With a timing light attached and cranking it over, sometimes I get constant firing and sometimes not. So it is intermittent at best. Now I have changed the points (checked the gap several times) and condenser, changed the coil, and to remove the voltage/alternator from the equation, ran a wire straight from the battery to the positive side of the coil, where I get the same results. My conclusion is the distributor is bad in some way. Before I get a new electronic distributor, I would like to ask if anyone has an opinion on a possible problem I have overlooked? Trying not to spend too much money on this thing as I have another engine on the side (V8 thanks to my nephew) to drop in come December and just need this engine to run until then.

I don't know under what conditions you were getting 12.9V, but if it was at the battery w/the engine running above an idle, it's not charging.

You should start w/a fully charged battery before going on to test things. I'd start w/the alternator and the battery cables and engine/charging system grounds.

[T-bucket23]

I agree with Cobalt, the alternator is still not working properly. I dont think that is the cause of your timing jumping around however. I would be suspicious of the points. You need to make sure they are adjusted with the point rubbing block on one of the high points on the cam. Make sure you put a dab of the proper grease on the rubbing block but do it sparingly as extra will just end up on the point surface. A dwell meter is a much more accurate measure. You didnt say what the engine is but if it is an SBC then gap .017-.019 or dwell 28-32 degrees.
Point adjustment directly effects timing.
You may also want to take a look at the wiring where it passes through the distributor housing. If it is cracked it can cause intermittent firing, also be sure it is not shorting internally to the plate.
My guess, and it is only a guess, is you have point adjustment issues.

[Rickus]

It's the original Isuzu 2.0 four cylinder engine. I have the new harness grounded pretty well and will check that plastic block on the side of the distributor where the condenser and coil wire attach. Didn't think of that point. Also, could I leave the plate out of the distributor for trouble shooting? It's just to keep crap out of the cap, right?