Long start problem (SOMETIMES)

[patrickpp14]

So i just bought my 2004 Mustang GT (40th Anniversary) convertible with only 60,000 miles on the clock...Clean title and the whole works but ive got a lil issue..Sometimes and this only happens like once every two days (and i drive every single day at least about 40 miles per day) when i come to start the car up, it sometimes takes like 15 cranks to start up as if its HARDLY starting. other times the car starts right up after like 3 cranks. I have changed the spark plugs (NGK inidum), flushed the coolant, Synthetic oil change, and i only use 91 octane fuel. When car is running, it runs smooth like no tomorrow, no issues, just the starting portion is weird. Could it be my fuel pump or starter motor?

CAR MODS: K&N intake, BBK throttle body, full Bassani exhaust

thank you everyone for taking the time to read up and help out

 

[Flghtmstr1]

Does the car do this when the engine is warm?

 

[Maxpowers]

Is it turning over slow?

I'd check the battery and charging system. It's a free service at advanced auto.

 

[GDawg]

Like Max asked, is it turning over slow when it takes 15 cranks? If so, you're most likely not getting enough voltage to the starter or the starter is going out.

Free testing at almost any auto parts store.

 

[joshjwc9]

It's more than likely the battery. If it's older than 3 years and you live in a hot climate that is it. Also, BTW you do not need to run 91/93 unless it is tuned for it. Your are actually hurting MPG's and not increasing your HP enough to realize the changes.

 

[trinity_gt]

My 02 GT used to do this way back when. Like when it was a year or two old and hardly modded. It was so embarrassing to sit there cranking for 5 seconds or more before it finally loped to life...

Then I got a tune. If I recall correctly, my car came with an MDE2 factory calibration and the dyno shop used MDE3 as their starting point (I may have these inverted...it's been years now...) and with the new calibration the problem was gone. I believe the problem was actually in the Ford calibration.

Sounds a bit like this:

http://www.stangnet.com/mustang-forums/479532-what-causing-my-car-have-extended-crank.html

I don't know if "ADRENLN" ever found a solution to his but my car was doing what he described and I don't recall it ever doing after the tune...