High FP when Double pmpr goes on, why?

[ThikStik]

Ive got ? brand of double pumpers-came with car. Ive got second pump staging on at 12 psi. Secondary pump is hot wired. The problem: the fp spikes 30 psi when it comes in. Ive changed regulator and verified a good return line. I even changed wiring so the primary and secondary pumps were reversed-still a spike when both pumps run. I have had chronic 900+ o2s on high end-regardless of FP setting. Any ideas.
TIA sephia.

 

[azgn]

you aren't using the fuel supplied.......certainly no need for a double pumper with your mods...disconnect one until you have a need for so much fuel volume (like 72's and 10's)

 

[Otto J]

had the same problem with mine,i just set it to turn on at anything above 20PSI and now its fine.Even with my combo there is no need for the second pump till over 20PSI
Otto

 

[V6 Beast]

If it's on the car in your sig then you aren't using the fuel. With a 44 and 009's you would only need it your starting FP was very high(50+) and running very high boost(28+). Even then you would only need the 2nd pump at the top end. I would adjust it till it came on later(like 20 that was suggested) or not at all. I went 10.95 on a single pump with a TE-64 and 50's.


Sully

 

[ThikStik]

Wow ! So i am way over-fueled. It just seems weird that the spike is 30 psi over reg setting. Could someone with DP's jump on their second pump while idling and duplicate this? Moot point , but just curious. As far as high o2s go, I did try running just the second pump and the darned o2s were still 920 on high end. This is even more weird considering that my boost starts at 12-14 when in 1st, 2nd and then hits 16 later in 3rd . Darn engine will need building by the time I get it right.
Thanks-Ill definately run the one pump.

 

[Doug Jacobson]

Wanna trade your setup for mine? It's a single 340, we can just swap the hangers and all if you'd like. Plus I'll throw in some cash to close the deal.

Doug J

 

[REDS HOT AIR]

you are nowhere near needing 2 pumps

if i turn booth mine on at idle it goes to mid 60's pressure ...the return line on our cars will not let it bleed off fast enough

 

[ThikStik]

Mid 60's, thats it. So youve got to burn it because you cant return it.
Thanks Red's