Stalling Fox when I downshift!!! Please Help!!

[gfrease442]

Hello Everyone, I need some help with my 90 LX 5.0 First, my list of mods...

75mm BBK EGR
75MM BBK Throttle Body
Trickflow Street UPPER & Lower Intake with 1" Spacer
Stock Heads
Stock Cam
Stock T5 with PRO 5.0 Short Throw
C&L 76mm MAF
MAC cold air intake
Stock 19# injectors
9mm Ford Racing plug wires
Ford Racing shorty headers
Dr. Gas X pipe
2.5" Flowmaster Mufflers

So with all that listed...my problem is when I first start the car when the engine is cold, the car starts and then dies if I don't give it some steady gas to keep the idle up. It then idles fine on its own after about 20 seconds of keeping my foot on the gas. The car runs fine then, but once it is warmed up and I push in the clutch to downshift while driving, the car wants to stall and sometimes does. It really wants to stall when I push in the clutch while downshifting from 2nd gear to 1st gear. Remember, this is only after the car is warmed up. What I'm thinking, but I don't know sh**, is that I have too much airflow from the trickflow intake and 76mm MAF and throttle body combo, but I'm not getting enough fuel due to the stock injectors and the car has never been tuned....or I have a vaccumm leak or something. The car ran stronger and had no issues before I added the intake, throttle body, and MAF combo...Also, could it be my TPS voltage? Any advice would be greatly appreciated and thank you..

P.S. Should I get 30# injectors or 24# injectors for my combo...and if I do get one of those injectors do I need to get a different fuel pump? What size fuel pump 190lp/h or 255lp/h? Thanks again

 

[HISSIN50]

Any codes? Pay real attention to any IAC, VSS or EGR codes.

Has the IAC been cleaned recently? Was the idle ever reset after the mods were done? I like my hot, no-load idle set so the IAC needs zero duty cycle to maintain 650 RPM (your idle might be set higher, but the same general idea applies - I use the IAC to compensate for loads but it's not necessary for the car to idle when hot and unloaded).
This would tie in with the dashpot issue (stalling while shifting), as it is the IAC that keeps the idle hanging a bit during shifts (so it won't stall).

That's where I'd start.
Good luck.