IHADAV8.com - Turbo Buick Tech, and Nonsense

Tech Area => General Buick Tech => Topic started by: Shimy87 on May 09 2014, 10:47:44 AM

Title: stupid fuel pressure question
Post by: Shimy87 on May 09 2014, 10:47:44 AM

So I am reading Steve site on tuning and have a TT chip. I take hose off FPR and set pressure to 43, put hose back on and go thru the setting of idle O2's in the 780-800 range set-up? Basically my question is, set FP at 43 with hose off to set base pressure, then put back on and tune from there?
 
Cant get brain to function today???

Title: Re: stupid fuel pressure question
Post by: Steve Wood on May 09 2014, 10:52:11 AM

Go down this page  http://www.vortexbuicks-etc.com/TuningBasics.htm (http://www.vortexbuicks-etc.com/TuningBasics.htm) and go down about 2/3's of the page to where it says "My Own Basic Assumptions" and read that section

Title: Re: stupid fuel pressure question
Post by: Kartune on February 23 2021, 08:40:58 PM

Hello, I'm new to this site and turbo Buicks.  I have an 86 T Type with a 60lbs injector turbo tweak combo, 255LPH fuel pump, and adjustable fuel pressure regulator.  I cannot get the pressure to go below below 45 lbs with vacuum line off.  I have also notice the pressure doesn't climb 1:1 with boost.  I have checked all the fuel lines and they are not blocked.  Any help appreciated...

Bill
ingle 255LPH Pump w/ QDto Barb Adapters for Buick1.00EA250 .000%250.002672-TBHW: Racetronix Buick Hot Wire Harness1.00EA6 2.000%62.003709-FI114961: 60LB Fuel Injectors DEKA EVO 1High Z6.00EA43.000%258.004788-BUICK5.7CHIP: TurboTweak Buick v5.7Chip1.00EA 109.000%109.005013-BREG: Buick Adjustable Fuel PressureRegula tor

Title: Re: stupid fuel pressure question
Post by: Steve Wood on February 24 2021, 09:13:53 AM

This does not sound like a return restriction to me.  Assuming your fuel pressure variations are correct and not the result of a faulty fuel pressure gauge, I would guess it is one of two things.

Either the fuel pressure regulator is seized up inside and you would have to take it apart and look at it, or, the steel line feeding vacuum/boost has a crack or hole in it so it is not sending a good signal to the regulator.  It is not that uncommon to have a problem with the steel lines that come off the vacuum block on top of the plenum.  Of course it could be a split hose that connects the vacuum block to the steel line on that end.

You can use a Mity Mite vacuum pump to apply vacuum to the regulator to see if pressure drops properly when you apply vacuum in order to determine if the regulator is simply not getting a signal thru the factory boost/vacuum hose

Title: Re: stupid fuel pressure question
Post by: Steve Wood on February 28 2021, 09:35:03 AM

Damn, Kartune!  You a one post wonder or were you looking for a no thinking answer?  :D