90 240sx with ka24e /white smoke but not headgasket?

[ka-beater]

I have a 1990 240sx with a ka24e. it has been having alot of problems but it started awhile ago.It was running rough and then it started spraying black liquid out of the muffler and it was smoking to.The smoke was white so I was thinking headgasket but to it to a mechanic. He checked and said it wasnt the headgasket, and he put sparkplugs in. now its idling fine and it stopped spraying the black stuff, but its still smoking. The mechanic did say that the fuel pressure had gone way up, but he found something unplugged and plugged it back in. Does it just need to be driven to clean itself out?

[180fan]

did the mechanic elaborate on the problem? like is the fpr stuck closed?

[ka-beater]

Im thinking he said it wasnt hooked up,and it cause my fuel pressure to go way up, but its normal now. My car starts and runs fine. Its just the smoke that gets bad and if I get on it you can hear backfire the minute i let off the gas. The mechanic said my lifters sounded weak and wanted to take my valve cover off but I decided to take it home instead. i got it home and i could hear injector wire #1 crackling. Well like a dumb **** I pull the fuse on the fuel pump to run the gas out of my engine but i was in to big of a hurry to put the injectors back in and I end up catching my engine on fire. Now my injector wires are toast but theres no more crackling and i have a new harness on the way. Would the fuel pressure go up if the fpr was unhooked?

[ka-beater]

i think i foud my problem by searching. Since my fuel pressure was so high it probrobly pushed gas past my piston rings and got into my oil. My oil smells like straight up gas so i think with an oil change ill be fine.