HI All,
Our 05 Mustang with the 4.0lt. and 55k miles has began to start a second or so slower than from new. We usually crank and it starts immediatly, now over the last couple of days it cranks for a second or so longer than normal before starting. New air filter, plugs and cleaned throttle body. Still no change. Any ideas would be appreciated.
Thanks
Bob

 

Is it cold up there in canada yet? That might be it.

 

Its not too cold up here yet, we still got another couple weeks till we start building our igloos. GRONOTTE, do you still have the original battery? I had the same issue earlier this year, it kept getting worse and worse. I changed the battery and it was back to normal. Give that a try.

 

Froze my butt off at the lake last weekend. It was 90F, 3 weeks ago, now its only 75F. It's tough, but someone has to be here.

The battery may be the problem, but with only 3 years on it seems somewhat premature. I'll load test and see.
Thanks
Bob

 

haha you guys are a riot. I'm from maine so kinda close, but i wasn't sure if it was getting cold in the mornings and that what you were talking about.

 

no sweat my dogsled team is well rested and ready to mush soon!

 

There's two common causes for this. Failing battery. Failing fuel pump.

 

I had this same problem a few months ago.

I just dismissed it at first thinking I would get around to having it checked out in the next few weeks, until not too long after my battery died..

 

same thing here.. changed battery problem solved..

 

Id change the battery and have you changed out your fuel filter yet? Every 15K miles you should do it..I did mine for the first time and she starts right up and purrs like when she was new..

even if its not this give it a go..For $15, you cant go wrong!!

https://mustangforums.com/forum/4-0l-v6-technical-discussions/332570-installing-fuel-filter-with-pics.html