Have I siezed my engine? Replaced starter but still not turning.

[jeffbarron79]

1990 s-15 jimmy 4.3L v6 auto

Truck ran fine then I let sit for two months. I then tried to start it with no success(prob. because I was out of gas or in need of tuneup or adjustments). It turned over on at least 10 different start attempts. It fired up once or twice but could not keep it going. Finally my battery died. I put in a new battery and the engine barely turned over. Sometimes I just got an attempt from the starter with no turning at all. Great I thought, I wrecked the starter. Now I have replaced the starter and battery and the engine still wont turn more than an 1/8 revolution. I have even removed the belt in case some other pulley was bad. Same Thing still. Perhqaps I flooded the engine but i have let it sit for a day with the throttle valves open to air out the intake and its dry in there now. Same thing. I have disconnected the injectors so no more gas goes in and have turned the engine almost a revolution to get the gas out of the cylinders yet still no luck. This engine seems siezed now or what is going on, I don't know. Thanks for any help. Perhaps when it fired up one of those times I bent a rod or something. It makes a medium- high pitch scraping noise when it moves only 1/16 revolution witch is all it will ever go when I try to start. I am clueless.

Broke down and greasy in Michigan.

[jeffbarron79]

Update, Removed all spark plugs also to officially drain the cylinders. Once I did this with the plugs out, I was able to turn the engine with the starter 3 or 4 revs with my new(yet already very low charge) battery. I was happy, I figured It was fixed. I put it all back together and with a few different combos of batteries I have gotten the same result - not even a 1/16 turn; just an engagement with minimal movement.

Also I have searched threads and saw a posting about crankshaft position sensors for 95-2000 4.3L engines that could go bad and cause a no start/hard start or other ailments. Could this relate to my 1990. Seems like I should get more turns than I am even if this was part of it.

Please someone reply if you have any suggestions at all. Like I said the engine turned over many times the very first time I tried to start it, so it seems unlogical that I could have seized or destroyed it so fast. There was plenty of oil in it. Is this a typical sign of internal engine problems such as oil pump failures, broken valves, bent camshafts etc.? Is there some generic term for this problem or something simple I am missing. I love my Jimmy and don't want this to be the end.

[jeffbarron79]

One more idea, what are the chances that A. My new starter is just junk. OR B. Bad Battery Cables (even though I have looked and they "look" just fine.

Also, this new starter is the third new starter I have put installed in the last 40,000 miles----what the heck!!


JB

[herkyhawki]

A 1990 motor does not have crankshaft position sensor.

You need to fully charge your battery before you go looking for other problems. Check the connections on both ends of the battery cables.