Setting fuel pressure

[OneLethal87GN]

After a very long engine rebuild I finally got the car back a few months ago. It's been sitting ever since due to my taking the time to get it looking decent again. Before the rebuild I had the problem of low pressure showing on my K-B hood-mounted gauge. It shows high 20s at idle when cold. When I turn the K-B boost-a-pump up all the way up it goes to low 40s. At high 20s the car stumbles and cuts off. It doesn't with the low 40s. When I go to set the pressure do I let the car reach operating temps first or just do it cold? I need to set the IAC too and know it needs to be warm when setting but wasn't sure about the fuel pressure. I plan on putting it back on the raod soon. I just want some new tires and rims first due to the car sitting in the guys front yard for 9 months and the rims rusting due to wet grass that sat in the rims after he cut it and it rained. Some white crap also showed up on the spinners and keeps coming back every time I clean it off. Also, I still have the 009s but with alot more airflow than before so should low boost and high timing be the way to go? I have both a street and a race chip but will get a Turbotweak chip burnt when I get the car on the road again.

 

[tc86gn]

It does not matter if it is warm or not to set the fuel pressure.

 

[TURBO2]

Do you have your Boost-A-Pump insatalled using the pressure
switch or without it?

 

[TURBO2]

Do you have your Boost-A-Pump insatalled using the pressure
switch or without it?

 

[OneLethal87GN]

Mine is mounted without the switch. I'll go out Wednesday and try to get the pressure up to at least mid 30s line on.

 

[TURBO2]

It's a lot easier to tune it in using the pressure switch. If your not going to use it, set the dial right in the middle then set your fuel pressure where you want it. That way if your just a little bit off you can use the dial to make small changes.

 

[WarpSpeed]

technically, you should set fuel pressure to what the car likes at wide open throttle, the computer will adjust to what is proper at any other throttle position, providing the chip is right.
I'd start at about 41, line on at idle.

 

[OneLethal87GN]

I'm not sure how your boost-a-pump works but mine doesn't even change until it goes past 40 on the dial. I can rotate the dial from 0 to 40 and the pressure doesn't change. When I go past 40 the speed of the pump doubles and the pressure suddenly jumps about 10-15 psi. I thought it was the switch so I replaced it...twice. It still does the same thing. i thought the boost-a-pump would adjust fuel slowly but it seems as if it only had 2 settings.

 

[azgn]

the "Boost-a pump" is not designed to regulate fuel presssure!

all it does is increase the voltage to the pump

what you are seeing is a voltage increase that causes more volume from the pump and overwhelms the return line, thus increasing your pressure

set your base fuel pressure with the regulator, vac line off, Boostapump off

if the "Boost a pump" changes your pressure, it is set too high!

it should only be turned on at WOT (via a boost switch)

 

[OneLethal87GN]

If it doesn't do anything from 1-40% then why even have those adjustments? I thought slowly turning the b-a-p up will slowly increase pressure. It says in the instructions to slowly adjust the pump for more pressure. It was designed to speed up the stock pump from 1-50%. Mine does nothing from 1-40% but after that it speeds the pump up to what sounds like twice the normal speed and the pressure jumps 10-15 psi. It is like this from 40-50%. It's like 1-40 is one adjustment and 40-50 is another. I even re-read the old "Double the Power" series in the Popular Hot Rodding mags and they even said you could bump the pressure either by the adj. regulator or the boost-a-pump. It just seems odd to me that there seem to be only two settings that even affect fuel pressure with this thing. I'm not trying to argue or say you are wrong I just thought this thing worked differently. I was going to try to hook it up with the Hobbs switch but I never got around to it.

 

[azgn]

the fuel pressure regulator controls fuel pressure

I repeat, if the "boost" raises fuel pressure, it is because you are overwhelming the return line (most likely at idle)

if you turned it on as intended (ie WOT only) your pressure would not be affected by the "Boost" since you would be using enough fuel to let the regulator do its job.......

using it like you are can only cause problems

I would disconnect it until you get the Hobbs hooked up (unless you are making a bunch of HP, you prolly don't need it anyhow....this ASSumes you have a good fuel pump.....)

 

[OneLethal87GN]

I don't use it wide open. I only have it turned to around 20-30%. It does raise the pressure while idling but only after 40%. I would have thought it would have done it gradually but oh well. I know I use the regulator to tune the pressure. I have a little bit of tuning ability. I just always wondered why it seemed as if there were only two settings when there should have been almost 50. The guy who used to do alot of work to my car even wondered that same thing. He is ASE certified and knows a good deal about turbo Regals. He has several and a Malibu with a GN drivetrain running low 10s. Thanks for the responses though. One last thing, I only run it full time because I don't have a hot-wire kit for my pump so this is basically the same thing so I keep it at 2-3 volts just the be sure the pump is getting enough juice.

 

[azgn]

I give up

good luck

ps: if that switch on the "boost" is anywhere close to accurate, a 40% increase means you are running about 18 volts on the pump (140% X 13 volts nominal.....)