Hi guys, hoping someone can help.
The trouble started a few days ago. 1991 ST184 with a 5SFE and 260,000 on the clock. Noticed a little bogging which got worse over the course of a couple of days to the point where it's nearly undriveable. I can slowly accelerate if I'm really careful and gentle, but push the accelerator a little too far and I very quickly lose power. This is much worse on uphill than on the flat or downhill. Babying it home I was holding up traffic taking off from the lights.
I started noticing the problem around the same time I ran the fuel tank down until the light came on, so my first suspect was a clogged fuel filter. Changed that out and the old filter was just filthy, so that seemed like a good bet, but the problem remained (though slightly improved, maybe?). So we thought maybe the filter in the tank was clogged too, but it was okay. (gave it a clean anyway). The fuel pump seems to be operating fine.
Checked the spark plugs, checked what sensors we could think of (throttle position, the two sensors on the cold air intake. Unplugging the coolant temp sensor or MAP sensor didn't net any positive results). Checked for any obvious leaks in the vacuum hoses. My mate poked around in the dizzy and cleaned some bits in there (he's better at this than me).
I stuck a paperclip in the ECU but it didn't throw any error codes.
The funny thing is, if you coax it gently past the bogging you can get it to rev up to 5k. I'm stumped.
Any ideas before I take it into the shop?
Oh, and there's oil coming out the dipstick hole, which hasn't happened before.
ANY suggestions appreciated.
Edit: compression test was 190 on all four cylinders.
Edited by Morelia, 16 June 2016 - 10:54 PM.