Fuel pressure drops instantly right befor boost 100-105kpa!!!
 

Ok guys I am having a problem here....

My fuel pressure will drop instantly right befor the motor gets into boost 100-105kpa... the motor will die if i keep on the throttle, if i let out it will studder and return to good idle.

I have a pressure gauge hooked up and is great till right befor boost and instantly drops off at boost... Motor runs great NA!

Setup:

1968 C10 pickup
5.3
T76 turbo/14PSI
4l80E/yank 3600
3/8 fuel line/ Dual Walbro in tank setup (1 on hobbs switch 5psi)


I replaced the fuel filter
voltage guage doesnt drop so alternator should be good
checked grounds for pumps
checked for kinked lines
both pumps hold 60ish at idle and hold pressure at 56ish when off
I know its not the Calculated airflow tables because they are set at max 4.1

Im at a loss! Going to check the rest fo the grounds on the pickup...

SO I tried connecting the second pump up directly so its on all the time and it still cut out and lost fuel pressue....

It never did this befor so i dont think its the tune.... has to be wiring somewhere

anyone else had an issue like this?

I just fixed a similar issue.. Ended up having a bad regulator

Thats whats next on my list! going to bypass it and just deadhead the pump and see if the issue is still there:D

Thanks for the tip!

is the reg boost referenced?

for now im just using the stock fbody regulator..... ive made 525hp in the past this way but will be switching soon...

I will be using a truck regulator on the fuel rails since its vaccuum/boost regulated (since im cheap and many have made ALOT of power on it)