2003 Jeep Cherokee engine turns but takes a long time to st

I have a 2003 Jeep Grand Cherokee and when I try to start it, it turns and turns before it actually starts. When it does finally start it revs up to about 1600RPM and as it is drops to it normal idle (900RPM) the needle for the RPM gauge jumps up and down, its not a smooth drop as when we first bought it. As it is doing this the jeep has kind of a rumbly feel to it and it smells of gas real bad. I took it to the dealership and they said it was the fuel pump so we replaced it, but the problem continued. There are sometimes when it starts right up but that is not always the case. Please help. Thank you 2carpros. Com.

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