Chevrolet: need help, j c whitney, auto electrician

Question
QUESTION: i bought Lumina LS Model 99.it has starting problem.it dosent start in first slef.if i stop car for one or more than one hour so its take 5 to 6 self for start.Mechanic told me it needs tuning so i did tuning.he changed spark plug and he cleaned fuel injector and somoe oter parts related to this.but the problem didnt solve.then he referd me to auto electrician,he checked and said its self is not working replace the self.i replaced the self, but the problem still there.now mechaninc is saying that could be its a fuel pump problem or another part(i dont know its name but it control the petrol just like carporater).
could u plz help me regarding this.

ANSWER:  HI
I would get a OBDII meter and it will tell you what is wrong. regulator ?

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QUESTION: what is OBD|| meter

Answer
OK- god move
I have found that the best price is at ( J.C.Whitney.com) they have been around for at least 50 yrs. it is a computer type meter that you will plug into your cars socket , it should be under the dash by the er,brake release it plugs into most all new cars as far back as 80s or early 90s  it will give out codes and the booklet will tell you what the code means, etc. and for less than 100.oo it is well worth it as you can even turn off the check engine light as long as the problem is not that serious. I would get one with a long cord like 3 or 4 feet.   ok than a mechanic can not tell you you need this when you only need a 10.00 part.