2G Eclipse GSX Fuel Trim dropping off at high RPM

[Beastd01]

I have a 1997 Eclipse GSX with the current mods listed below
1000cc fuel injectors
255 fuel pump
20g evo III turbo
Greddy IC
Speed Density
ECM Link
93 tuned
AFPR
4 bar map sensor

My fuel pressure gauge reads 42.5-43psi with those current mods and have 0 issues. Now I added the below and am having this current issue at higher RPM:
Same mods but now:
FP Red turbo & Manifold
external o2 WG
JMF Street IM
Bigger IC
MAC Boost controller
GM IAT

I went to double check my AFPR and was able to get it to the correct parameters but once I connect the vacuum source it drops to 36psi. What could be some causes of this if this has happened to anyone? The car was doing so well until high RPM's and the fuel pressure started dropping causing the car to go lean.

 

[steve]

It's normal for the fuel pressure to drop when the engine has manifold vacuum. Base pressure setting it with atmospheric pressure @ the FPR and you should see the fuel pressure rise 1:1 starting with boost. Depending on your normal idling manifold vacuum you should see it drop about 1 psi for each 2 inhg vacuum.

 

[Beastd01]

It's normal for the fuel pressure to drop when the engine has manifold vacuum. Base pressure setting it with atmospheric pressure @ the FPR and you should see the fuel pressure rise 1:1 starting with boost. Depending on your normal idling manifold vacuum you should see it drop about 1 psi for each 2 inhg vacuum.

Forgive my lack of knowledge on this but from your response this sounds normal at idle but will need to verify in ECM link when driving?

 

[steve]

You might want to read both the 1G and 2G DSM Technical Manuals. There is an enormous amount of background information on how things work. You can links to both in the resources portion of this site. https://www.dsmtuners.com/forum/articles-manuals-documents.262/

Unless you have added a pressure sensor to log the fuel ECMLink won't directly verify. You can test the functioning of your AFPR by switching on the fuel pump in ECMLink and applying vacuum and air pressure to the manifold reference port on the AFPR and watching how the fuel pressure changes.

Once that's verified posting a log of the problem your having might give us a better idea what's going on.