ok so multiple major issues here, right-
assuming none of the computer issues were present before the rebuild?
what modifications were present before this and what are present after the rebuild?
1-need to get ALL the codes while you still have communication with the ecm/bcm/tcm/modules.
a-B, U, P, codes, need all of them
b- reduced engine power- this could be a million things, but PROBABLY related to throttle body or MAF sensor or both
c- maybe the fuse block deal, but if nothing was happening BEFORE the remove/replace on the engine then eh
2-oil pressure
a-well, since you have consistent oil pressure, you probably have a dogbone in the back of your block, unlike someone on here a few months ago or whatever because the builder didn't install it. so that's good. it's just low, right, so ya it would be interesting to see what the mechanical gauge says at the oil pressure sensor port and the port on the block behind the power steering pump, but that's a pain to get to. I don't remember what the minimum spec on oil pressure is, but the computer will send the truck into reduced power mode if oil pressure drops too low. I'm not saying this is it, I'm saying this will do it.
b- ya could be the o ring, absolutely. I'm not an engine builder, but I do know bearings and clearances are taken into account when building an engine, a stockish rebuild should be compatible with damn near anything out there, you can put 5w30 in it, 10w 40, whatever, it should be fine. obviously people get wrapped around the axle on oil weights and this and that, but its a gen 4 gm engine. it will eat what you throw at it, designed to eat 5w30 from the factory. You should see 20-30 at hot idle and 40-50 at higher rpms.
3- oxygen sensors
a- this isn't that big of a deal right now, but it would be good to check out the tune to see what, if any changes were made by a previous owner/tuner/shop/whatever.
b-these not working aren't that big of a deal right now, imo
As far as the wiring, ya a general continuity check on every wire would be good... make sure nothing is shorted to ground that isn't supposed to be. Make sure you have contiuity from the connector at the ecm to each sensor connector pin. The forum has great schematics in the electrical section, i think. Ya these intermittent things are a pain. Start with the electrical/wiring, two cents. this is my opinion
![Rectangle Font Line Screenshot Parallel]()
assuming none of the computer issues were present before the rebuild?
what modifications were present before this and what are present after the rebuild?
1-need to get ALL the codes while you still have communication with the ecm/bcm/tcm/modules.
a-B, U, P, codes, need all of them
b- reduced engine power- this could be a million things, but PROBABLY related to throttle body or MAF sensor or both
c- maybe the fuse block deal, but if nothing was happening BEFORE the remove/replace on the engine then eh
2-oil pressure
a-well, since you have consistent oil pressure, you probably have a dogbone in the back of your block, unlike someone on here a few months ago or whatever because the builder didn't install it. so that's good. it's just low, right, so ya it would be interesting to see what the mechanical gauge says at the oil pressure sensor port and the port on the block behind the power steering pump, but that's a pain to get to. I don't remember what the minimum spec on oil pressure is, but the computer will send the truck into reduced power mode if oil pressure drops too low. I'm not saying this is it, I'm saying this will do it.
b- ya could be the o ring, absolutely. I'm not an engine builder, but I do know bearings and clearances are taken into account when building an engine, a stockish rebuild should be compatible with damn near anything out there, you can put 5w30 in it, 10w 40, whatever, it should be fine. obviously people get wrapped around the axle on oil weights and this and that, but its a gen 4 gm engine. it will eat what you throw at it, designed to eat 5w30 from the factory. You should see 20-30 at hot idle and 40-50 at higher rpms.
3- oxygen sensors
a- this isn't that big of a deal right now, but it would be good to check out the tune to see what, if any changes were made by a previous owner/tuner/shop/whatever.
b-these not working aren't that big of a deal right now, imo
As far as the wiring, ya a general continuity check on every wire would be good... make sure nothing is shorted to ground that isn't supposed to be. Make sure you have contiuity from the connector at the ecm to each sensor connector pin. The forum has great schematics in the electrical section, i think. Ya these intermittent things are a pain. Start with the electrical/wiring, two cents. this is my opinion
