1G Upping the 1G Base Fuel Pressure to 43.5 same as 2G helpful?

[Bladeliger]

I'm dealing with boost creep on a 14B turbo and decided to just do the fuel mods to balance it out.

But I'm on a tight budget and buying the sections in installment. I have completed the AFPR section and I'm already running a 190Lph and rewired walbro.

Will installing the AFPR and upping the base pressure to 2G levels help me a bit not to be too lean when I'm pulling with boost creep or will this just hurt my stock set up.

Thank you.

 

[Vegas Smith]

Yes, it would but at the cost of worsening your idle and cruise. I would think the 190 could handle the 14b, though, or just buy a cheap walbro 255.

 

[Bladeliger]

Yes, it would but at the cost of worsening your idle and cruise. I would think the 190 could handle the 14b, though, or just buy a cheap walbro 255.

Thanks for the advice will try if the ecu can compensate in the idle and cruise.

 

[We're on Boost]

ECU range of closed loop fuel trim adjustment, according to some old Pocket Logger info I saved a long time ago:

Range of 60% to 140% for 1991-1994.

Range of 80% to 120% for 1990.

Boost creep seems weird though, I mean, if it is a lot of creep. So it would be best if you knew what was causing the creep and could fix it.

 

[Bladeliger]

ECU range of closed loop fuel trim adjustment, according to some old Pocket Logger info I saved a long time ago:

Range of 60% to 140% for 1991-1994.

Range of 80% to 120% for 1990.

Boost creep seems weird though, I mean, if it is a lot of creep. So it would be best if you knew what was causing the creep and could fix it.

Hi,

I think it's the internal wastegate. O2 housing not ported but It improved when I installed a 34mm flapper housing from kinugawa and installed a 2.5" downpipe from RRE as opposed to my 3" downpipe.

I have bypassed the mbc and have direct line from the j pipe to the actuator and still creeps at higher rpm up to 20 psi

I have no cat and 3" catback and a front mount intercooler with custom piping.

Thank you.

 

[We're on Boost]

Wow. Well, it sounds like the actuator is bad then? If the diaphragm in it is leaky it would probably act like you are describing. I'm a little rusty about the stock internal wastegate and actuator though.
Thinking it would be interesting to take the hose off of the J-pipe fitting and put an air nozzle to it from an air compressor with a gauge on it and an adjustable regulator. See what pressure it takes to move the rod to the flapper, and listen for air leaks. And see if you can rotate the flapper through its full range that way.

 

[Bladeliger]

Wow. Well, it sounds like the actuator is bad then? If the diaphragm in it is leaky it would probably act like you are describing. I'm a little rusty about the stock internal wastegate and actuator though.
Thinking it would be interesting to take the hose off of the J-pipe fitting and put an air nozzle to it from an air compressor with a gauge on it and an adjustable regulator. See what pressure it takes to move the rod to the flapper, and listen for air leaks. And see if you can rotate the flapper through its full range that way.

Yeah never tested the actuator but I have ordered a new one and will replace it

Thanks

 

[We're on Boost]

Yeah! Should work.

 

[Bud92gsx]

Opening the exhaust alone without porting the turbine housing can cause sum creep in some cases. In some cases no.
Since you have ordered a new diaphragm l, try that first.
I used auto fuel pressure on 450s and a rewired pump, and 2g maf for a year or two with no issues that I know of. I know you mentioned going to 43 psi fuel pressure so I'll just throw that out there.