problem at 7000 rpm on mpi s/c

[motohd66]

hey im running a apex with a stage 1 mpi with 7-8 lbs of boost at 1300 ft. and no matter what i do i cant get it to run at the 6750-7250 rpm range, i have tried the mpi box and with a pc111, i can roll past this rpm and it runs great but i am barely in the throttle alot at that rpm because of trail riding (thats all i do). most of the time at that rpm it will go to around 10:1 at 7000 and then go completely lean to 15:1 within 250 rpm and when i skip past this rpm to say 8000 it goes to 10:1 when i let off the throttle and the sled seems like it dies.
thanks,
confused!!

 

[motohd66]

anybody??? we tried moving where it senses boost to the throttle boddies v.s. the nipple on the intercooler, helped a little, next i am trying fuel pressure, but its too warm here today.

 

[badluck]

What are your fuel settings on the MPI box?

 

[motohd66]

mode 1 - 1
mode 2 - 2.5
mode 3 - 2
mode 4 - 4.5
mode 5 - 1
mode 6 - 8
it seems no matter what i do either i get it to run just ok slowly through the 7000 rpm range but then i get the cut out when i let off the throttle at higher rpm's or i fix the cut out and it runs like crap through the 7000 range, i just cant find a happy medium!!! i get the same results with the pc 111 with a 3 bar gm sensor

 

[Ted Jannetty]

mode 1 - 1
mode 2 - 2.5
mode 3 - 2
mode 4 - 4.5
mode 5 - 1
mode 6 - 8
it seems no matter what i do either i get it to run just ok slowly through the 7000 rpm range but then i get the cut out when i let off the throttle at higher rpm's or i fix the cut out and it runs like crap through the 7000 range, i just cant find a happy medium!!! i get the same results with the pc 111 with a 3 bar gm sensor

You should be running a 2 bar map sensor not a 3 bar.
Do you have a Bypass valve on this set up?
There has to be something that changes rapidly at 7000 rpm to cause this condition.
What about Plugs, What are they gapped at?
Should be 024

Ted.

 

[motohd66]

mode 1 - 1
mode 2 - 2.5
mode 3 - 2
mode 4 - 4.5
mode 5 - 1
mode 6 - 8
it seems no matter what i do either i get it to run just ok slowly through the 7000 rpm range but then i get the cut out when i let off the throttle at higher rpm's or i fix the cut out and it runs like crap through the 7000 range, i just cant find a happy medium!!! i get the same results with the pc 111 with a 3 bar gm sensor

You should be running a 2 bar map sensor not a 3 bar.
Do you have a Bypass valve on this set up?
There has to be something that changes rapidly at 7000 rpm to cause this condition.
What about Plugs, What are they gapped at?
Should be 024

Ted.

im hearing that about the map sensor but i have heard it has been done (im not trying to argue) but it reacts the exact same way as far as the mpi box vs. the pc111, no i dont have a bv on the kit, its exactly like it was sent from mpi, i did not check the plug gap so its whatever they were stock w/ stock plugs
thanks
brent

 

[Anonymous]

Please call me here at mpi and i will get you helped out, Thanks Skyler 888-649-4609 ext121