1993 Blazer questions

Vehicle Information:
1993 Blazer "W" 4.3 CPI
62K miles

Ok here is my problem. I have searched the threads and haven't really found any that relate to my problem directly. I just bought this Blazer about 2 weeks ago for $1500. THe thing runs excellent and has plenty of power. I really haven't done much to it yet as it needed a really good detailing which has made quite a difference after 4 coats of wax. Anyway, it starts right up in the morning and shoots out a purpleish/blackish smoke. Tailpipe has its fair share of carbon in it also. I am not aware of previous maintanence on this vehicle other than I know it had a full tune up including plugs, wires, cap, button etc.. within the last year or so. I have not changed the oil yet because I have been so busy and I know that it has been quite some time since it was changed last. I put a new flowmaster muffler on it because the old one was totally spent. THe main problem that I am having is that after I start it in the morning or whenever and drive it to school, it takes awhile to get it started again after 6 or 7 hours. While at a stop light the idle is not as smooth as it should be either. Not rough but not smooth either. Now if you drive it and let it sit less than a 1/2 hour it fires right up. I really don't think it has to do with the CPI or anything because I am not having the usual symtoms of loss of power and raw fuel smells. The exhaust stinks more than it should, but the cat checks out ok and it did pass emissions when I took it through inspection. My guess is maybe the EGR valve needs cleaning or maybe something else?? THe oil pressure also seems a little low like 40ish when its cold and around 10-15psi when its warmed up. Maybe a bad oil pressure sending unit?? Also there is no check engine light on nor has it come on at all.Gas mileage when I filled it up averaged 15.5 miles to the gallon-mostly stop and go under 50mph traffic. :screwy:

Thanks for any information you can give me, it will be greatly appreciated.

Ok, check your CPI injector and nutkit for leaking.

Remove the top VORTEC cover play, remove the round IMTV valve underneath it and then look down inside and smell for gas and look for washed spots where there is not black normal soot deposits.

Look for pools of fuel.

Alsi, consider a full tuneup and don't believe the previous owner when he said everything has been done.

Fuel filter
Spark plugs AC Delco only
Cap & Rotor
Air Filter
PCV Valve

Also remove the timing wire from the ECM and get your engine properly timed.

Check your oil and replace it ASAP if it smell like gas. Your CPI injector leaking could be flooding the oil with fuel.

You are going to have to spend close to $400-$500 so you need to do it or take it back.

Ok I pulled off the cover and the valve and looked down in there. Its dirty all over, didn't see any pools of fuel, there was one spot on the left side where it was gold which I would assume is from washing. I guess I have a small leak in there somewhere. I did smell fuel when I took out the valve but not overwhelming. Oil smells fine, no gas smells or anything. Besides the Cpi and nut kit could there be anything else wrong, I read that sometimes the fuel pressure regulator can go bad and cause a host of problems also?
Thanks

Fuel pressure regulator is part of the injector.