Primary/secondary fuel pumps?

[HawkeyeScott]

Wife drives a 2007 Chrysler Pacifica 4.0 with 147K miles, original owner. Planning on doing proactive maintenance on it this spring to replace some things that are likely on borrowed time (original equipment). This is an investment in my wife not breaking down and getting stranded and, related, my general wellbeing and happiness.

One of them is the fuel pump. When I look up parts, I see a primary and secondary pump listed. To my knowledge, I've never owned a car with two pumps before. Is one a back-up? Do they work in tandem? Do I need to replace both?

This car was built when Daimler owned Chrysler and it has some Mercedes-style components and I wonder if this is another example.

This is a blind spot for me. Thanks a lot.

 

[HawkeyeScott]

Nothing on this?

 

[repairman54]

Some vehicles have split or saddle tanks so 2 fuel pumps are used. One to pump fuel to the other sides tank for pumping up to engine.
Not sure if you have split tanks, common on a lot of AWD vehicles.

 

[JTK]

I was going to ask is it direct injected, but that 4.0L is not. GDI uses a typical in-tank E-pump that feeds a high pressure mechanical pump driven by the engine.

Either which way, I would not consider an in-tank fuel pump as being a PM item. The quality of the replacement could be worse than what is in there presently.

 

[D60]

Ford loved this from '85 to 89. In '90 they went single in-tank pumps which was soooo much better.

The in-tank pump was low pressure and fed the high pressure on the framerail.

That said, I still vote to return to the Ford "clothes pin" fuel line clips. Sure, they often broke when you tried to pull them but they were dirt cheap and wouldn't clog with crap like all the "fingers" that need a disconnect tool