Help!!!! My truck is F'd!

[89blue1500]

Ok guys, here is the scoop. I have a 94 full size blazer. It is becoming a money pit, well more like a giant black hole that devours my pay from both jobs! Yesterday on my way home from job one it started to act up. First was loss of power when I was about ten min from home. It just didn't want to get out of its own way. When I was slowing down for my drive way it lost all oil pressure and shut itself off! I was like WTF !! Automatics can stall??? I coasted into my drive way with no power steering (those extra push ups really do help!) I tried to start it and it had the low battery sound to it (slow cranking). But after a like ten min it started right up and I parked it with no oil pressure (7pm). Now last night (1am) I tried to start it to go to job number two. It started and got oil pressure immediately and ran fine. About two min down the road it lost all power and oil pressure. I turned around and the oil pressure stayed at 20psi until I parked it and then it went to zero and shut itself off again.

Now on Saturday I just did an intake gasket, and last Wednesday I did a starter, and the previous Monday my room mates girl backed into it doing somewhere in the 30mph mark(they were fighting lol) and I had to replace the trans cooler. And if you wana go back further, in January I put a new tranny in.

Ok now with the question.
WTF is wrong? The only thing me and a couple of DIYers think it could be is the oil pump. As you can tell I all so have an 89 k5 project and the motor is the same. So I was planning on take that out to put in the 94 for now until I figure out what’s up. And I have to say that I need to get this fixed/figured out because the boggers on my not so street legal J*** are bald and the whole thing is not very legal to drive to work.

Any ideas are greatly appreciated.

Thanks Rob

 

[Seafarer76]

I would actually check the charging system first. Make sure that the alternator is charging the battery. Put a voltmeter on the battery with the truck off and with the engine running. The oil pressure guage is electrical in there, so an electrical problem will make it go wacky. I can't say for certain, but i am pretty sure those trucks don't have a low oil pressure safety cutout. If the oil pump goes, you lose oil pressure, but the engine will continue to run until you spin a bearing or throw a rod.

Check with a voltmeter....the battery should be about 12-12.5 volts with the engine off and around 14 with the engine running. I almost guarantee that you have bad alternator, voltage regulator or connection.

 

[scouthead]

I wouldn't get into motor swaps just yet, there are just way too many things that could be wrong that don't have anything to do with the engine itself. Sounds electrical... as far as the engine cutting out,(if you still have voltage) you might start looking at the ignition system?

 

[89blue1500]

Sorry i forgot to say earlier that the motor knocks when the gauge says no pressure. Well as soon as i get home i will check the battery which i have never had a problem with an optima. and the voltmeter says 12 with the key on and 15 with the motor running but i will double check with a meter.

--
Rob