Low Oil Pressure and lackluster performance after warming up

[Chase]

After I bought my 94 305 TBI I drove it from the guys house to a local shop for a full blown tuneup (plugs, wires, new exhaust, basic things that a 24 year old truck would need replaced. I'll start by saying every GM I've ever owned (Silverado, Camaro, Corvette, etc.) has read low oil pressure, ideally at a stop after running, but not to the point that this one has.

When first cranking the truck and driving for about 5 minutes, the oil pressure reads strong at 40 and up when accelerating, but after driving it drops down to between 10-20 and sits at 10 when stopped, no gauge warning or anything of that nature and it drives fine if you stay under 2k when accelerating to whatever speed you're getting to.

Issue comes into play when getting on the gas hard from a stop (oil pressure between 10-20psi), truck sputters as if (best way I know to explain it) like it's not getting any gas at all, doesn't die or shut off, just sputters like a madman trying to get up and go, but once I break 2k rpms the oil pressure shoots back up to 40 and acts like nothing is wrong.

Going down the road doing between 60-70 turning anywhere between 1500 and 1800 at best, the truck runs fine until needing to downshift to go up a hill/higher elevation/etc. and does the same thing again with the sputtering and shaking like crazy until it breaks 2 grand and gets sufficient oil pressure, then acts like nothing is wrong afterwards.

Guesses at the moment are bad oil pump, dead cylinder, bad bearings before I take it back into be combed over. Just wondering if anyone else experienced issues similar to these and what your remedies were.

 

[evilunclegrimace]

The oil pressure is within spec and more than likely has nothing to do with the drive ability problem. I would check fuel pressure and fuel filter before condemning an oil pump. A dead cylinder would most likely cause a miss/skip/shake regardless of RPM. Bad bearings would more often than not make noise when hot at idle.

 

[Chase]

The oil pressure is within spec and more than likely has nothing to do with the drive ability problem. I would check fuel pressure and fuel filter before condemning an oil pump. A dead cylinder would most likely cause a miss/skip/shake regardless of RPM. Bad bearings would more often than not make noise when hot at idle.

Meant to add I had one of those put on as well, I know the fuel pumps themselves can be hit or miss in these trucks but I'll have the pressure checked this week as well. Forgot to add on a side note one of my relatives took the throttle body apart "trying to make the truck faster" a few years back and for all I know it wasn't put back together properly, or the thin fuel lines on the throttle body could be stopped up. I've ran a can of seafoam the last two tanks trying to clean it out and put some Lucas oil stabilizer in it earlier today to see if that would help. I'm just a tad OCD when it comes to readings not being where I think they ideally should be, and the low oil pressure readings have just sent my mind into thinking the worst.

 

[grampadirt]

I wonder if your relative tried the fuel pressure regulator mod,might've messed it up.

 

[Chase]

I wonder if your relative tried the fuel pressure regulator mod,might've messed it up.

I don't think so, friend of mines dad put it back together, said he had just tore it apart and didn't know what he was doing. I had planned on putting a new throttle body on it soon anyway.

 

[grampadirt]

I don't think so, friend of mines dad put it back together, said he had just tore it apart and didn't know what he was doing. I had planned on putting a new throttle body on it soon anyway.