Hard to start 3.1
 

I have a 98 Monte Carlo with the 3.1L engine. I don't have a long history with the car so I don't know what has been done in the past. It is slow to start, meaning it cranks and cranks before starting. Not a slow cranking, so it's not a battery issue. I did change the plugs and they looked to be original. The car has 104,000 miles on it. I have no check engine lights and the car seems to run fine other than being hard to start. I just finished a 3,500 mile road trip with it and it ran great getting as much as 30 MPG on the highway. Any ideas where to start? I was thinking maybe the fuel pump is getting weak but I really didn't want to start there, I assume it's in the tank.

Are you 100% it's not the battery?

I would imagine it could be the starter, or possibly the car isn't getting the proper fuel right away?

Definitely not the battery or starter. It cranks at normal speed, just turns over too long before finally starting.

You may want to get a fuel pressure guage and look up what the right pressure is and check it. See if the pressure is weak. I was just recently helping my step-brother with an issue where his fuel pump died (it hummed like it worked, but was not outputting any pressure).

Other then that, you did plugs. Did you also change the wires? FYI - Don't use BOSCH plugs, they are junk in GM v6's. I have used BOSCH wires on a LOT fo cars, the wires are fine, just steer clear of the plugs.

Also, change the air and fuel filters. If the fuel filter is beginning to clog up, that will also stress the fuel pump (promoting an earlier failure of it).

Since you don't know the car's history, those are some good maintenance things to do "just because" (I'd also change the transmission fluid and filter if you are at 100K miles, I just changed did that for the second time on my '94 Grand Am with 210K on it).

Other then that, I'm thinking battery and/or starter. It may be cranking and sound normal but possibly be a tad too slow to get the job done. Most auto parts stores can do a battery altenator test for free, could be worth a try.

I installed AC plugs, didn't do the wires though, they look decent but I guess they could be breaking down internally.
I though about fuel pressure testing but I would need to buy a guage and I'm not real sure how to hook it into the system. I guess I could connect it where the fuel pump connects?
The air filter is new but I didn't change the fuel filter. I think I'll start there since that is relatively cheap and I don't think it's been changed in a while, if ever.
Thanks for the advice.