My engine is hard starting

I have a 1999 chevy 2500 with U motor. I just replaced the in tank fuel pump and also the fuel filter after I started to have starting problems and then it seemed to run sluggishly under load and just now 1200 miles from home, I just barely got it to my brother's house with lots of popping and no power. I have gotten two incidences of low oil level requiring adding 2 quarts of oil. I do get a smell of oil when it does start (usually 3 to 4 cranks). I don't want to get stranded and I don't want the expense of a dealership if I can help it. I am stranded and need a response quickly. I am standing by at the computer now.

Starter engine (two cranks) removed fp relay and enginer stallled. Swapped out a/c relay, isolated O2 sensors. I am getting a little ticking sound that appears to come from the front of the engine and is engine speed dependent.

Also, can the fuel pressure regulator when failing or failed produce the same hard starting symptoms due to not holding fuel in the fuel rails and if failed would operation of the engine become sluggish w/o power (liken to fuel starvation).

I do hear the pump running and also I get spray of fuel from fuel port (need to get a pressure gage?) To get exact number.

A local chevy tech suggested that the fuel pressure regulator may be suspect. There is vacumn supply to it, but he suggested that it may be responsible for allowing fuel in the fuel racks to drain back to the fuel tank and have to be recharged before starting. Comments, please

When I turn over the engine on my 99 silverado, it usally takes a few seconds to start, and when it does, it slowly chuggs up to the idle speed, almost as if it wasnt getting any gas. I have recently replaced the fuel pump and filter, done a fuel intake cleaning service, changed the air filter, cleaned the intake manifold at the butterfly valve, changed the spark plugs. And yet it still has this problem. Im not sure if its a problem with the fuel injectors, or mabey the computor. But once its started and at idle speed, it drives just fine, every once in a while when I come to a stop, the idle drops down but then chuggs its way back up. Any idea of what the problem might be?

Also check the mass air flow sensor, if it is going bad it won't read the correct air intake and you won't be getting enough fuel into the motor.

If the truck sits for a few hours it takes longer than normal to start. If I drive the truck for a while shut it off and then start it again it will fire right up. Any suggestions?

If I cycle the key 3 times as described the truck will fire right up. We replaced the fuel filter the other day and after sitting all night the truck fired right up in the morning. After the truck sat again for 4 hours it had the extended crank again. Just making sure there arent any more possibilities before I replace the fuel pump

Need to crank engine six to eight times before will start. Also, sometimes come out and battery is drained. Once I was told horn was going off constantly for hours until stopped. Because battery was drained. Disconnected horn and relay.

Fuel pump runs. Not sure about spark. But always seems to start after six to eight cranks.

I have checked that port by pushing down on relief valve and fuel shot out immediately. But I probably still need to check pressure. Also, I just went out to see if tachometer moved while cranking and of course it started first crank.

Where and what does the crank sensor do?