Quoting a past post that also goes along with a problem i have

[lilrogue78]

Re: Struggling with a miss what type fuel delivery system do I have ?
Your engine has CPI. The system uses the "spider" assembly. There is a fuel pressure regulator, one fuel pressure line to the injector and one return line from the fuel pressure regulator called a "nut kit", and the injector assembly. All are located under the plenum. A fuel pressure test will tell you if the fuel delivery system is working properly. If there is a leak in the system, it can cause the P0300 to be set. It can also cause poor fuel mileage, possibly a fuel odor, hesitation, stalling, hard starting, and generally poor performance.


Welp here is goes i bought my 93 blazer 4.3Vortec and has the problems described. So i changed my plugs and wires to find TONS of carbon build up and that made it run a little better. So i then changed my o2-sensor to find that it was unpluged so i was getting a Open/Shorted Oxygen Sensor code.
So i pluged it back in and ran worse so i bought a brand new one well guess what NO CODE! yay! but still the same dumb problems so i tore the EGR valve off and that was all carboned up so i cleaned it all up really nice with brake cleaner and it runs a tad bit better now. But i forgot to mention i drove it home (2miles) with about 10Quarts of oil in it and after i changed my oil and over flowing my drain pan just about it helped ALOT so if anybody knows what else to change let me know. OH btw i have yet to change my plugs again seince all these repairs

[old_master]

10 Qts of oil? Are you sure it wasn't fuel mixed in with it? This could be a fuel system problem.

[lilrogue78]

yea it had also of gas in it also i figured that was because of the plugs in the driverside not firing and being soaked all the time so i figured it was just running down into the oil pan from that so i looked around under it and found that the crossover pipe was crushed so i went to cut that out to replace it and about a cupfull of gas ran out and now that i replaced the pipe it still dont run right so any ideas?

[old_master]

Check fuel pressure and leakdown.

[lilrogue78]

You guys are great i read the "Nut Kit" bulliton and that was all i needed it was spraying so much gas out that line i am suprised it would even run i only had MAX 15LB psi ...wow but changed it and runs WONDERFUL there should be a tutorial and sticky done for that fix

[old_master]

Here's one from the "How To" section in the Blazer forum. http://www.automotiveforums.com/vbul...d.php?t=473110

The fuel delivery system is prone to several problems, that's why fuel pressure and leak down should be checked first, whenever you have a driveability issue. Make sure you change your oil and filter now, and again after 100 miles or so. Fuel dilutes oil immediately and diluted oil can permanantly damage the engine.

[lilrogue78]

complete oil change doen today and took it out two trackin' tonight ran perfect ..put 100 miles on it just wheelin so gonna do another change at 300 miles i checked the oil .... still golden brown ...must have been from alll the fuel cleaning it out