C15 acert upgraded fuel transfer pump question

The New C15 acert upgraded T-pump does not come with upgraded spring. You need to install it separately if you want.

 

Do you happen to have the part number for the spring my local cat shop acts like they don't know what I'm talking about

 

P/N 339-4983 this will fit the pump with allen head bolt

 

I have a '05 Pete with a mxs. I shimmed the t pump the other day and this was my results.
82 lbs. Before 83 lbs after @ idle
90 lbs before 92 lbs after @ 1000rpm
91 lbs before 105 lbs after @ 1500 rpm
92 lbs before . 110 lbs after @ 1800 rpm
I was expecting more of an increase at the lower rpm. Is this normal or should I add more shim or does this mean I need a new t pump? I did not notice any difference in performance but have not driven much since I shimmed pump nor have I checked mpg difference.

 

Your numbers weren't bad before and are where you wanna be now. So you're not going to notice a huge difference.

I'd leave it alone .

 

I know this is an old post, but was wondering if the new spring will fit the old (2000) transfer pump?

 

In all reality while the spring may gain you some, you should really be swapping to the SDP pump all together to see the best gains.

 

By SDP, are you referring to the 2008 SDP C15? If so, what benefits would I see by switching to that pump?
I actually don't need to replace my spring in the transfer pump. At idle, cold, with the return line blocked off, my pump is putting out 123 psi; hot...it's 116 psi.
My fuel pressure hot is 85 psi (90 psi cold), at 700 rpm (idle), and 108 psi (hot) at 1700 rpm.
I was just curious, without researching further, if the updated spring would work in my original t-pump.
Thanks for the reply.

 

On a stock engine probably nothing.

 

Who said anything about “stock?”