Ok first the mods to the car, I bought it this way so I may be missing something.

87 T2
RR ported rebuild with 540 miles on it so far
S5 intake manis
RB exhaust
Ported WG
Removed emmisions
Removed CAS
TB mod
RB exhaust


Things I have done to try and fix the problem.

Reworked the vacuum lines and fixed all leaks
Set TPS via Teds website
Set timing
Changed plugs
Changed Fuel filter
Had injectrs cleaned.

The problems I am having.

The throttle must be held open a small amount for the car it start at all
Car tries to idle for a split second then drops to 500rpm then dies
Unresposive to throttle input to keep car alive, but is fine above 2k rpm, meaning the throttle picks up very well and is smooth.

Any help please.

 

Fuel pump might be bad or seeing low voltage (that could be a bad resistor pack/bad ground) or fuel filter or sock.

Actually it might be a vacuum leak. That's a really common problem and often has similar symptoms. Also could be a cruddy alternator, not pumping out 14.5V to the system.

 

I knew i forgot something I rewired the Fuel pump, and I'll check for leaks again maybe I missed something

 

I went out before it got to late and looked over the car again and I cant seem to find any leaks on the intake side anywhere.

 

Still cant get this thing to idle any help would be appreciated

 

throttle cable is loose? Ive had running issues because my throttle cable was a hair too loose.

 

A loose throttle cable would only mean that the throttle plates were closed to far and not letting enough air in to idle, you should adjust your throttle stop to cure that problem for you

 

I just tried jumpering the lil yellow connector on the passenger side. I got it to idle at 800rpm for about 10 seconds and it still dies.

 

i'm having this exact same problem... i have to put the pedal to the floor to start it..then kep it above 2k ...2k up it rev good but below kills the engine

 

you say you have a s5 intake mani... do you also have the s5 injectors? if so you will need to remove and bypass the resistor pack that came in pre 87.5 t2's... its a small aluminum box mounted right behind the passenger headlight under where the air box should be... it has 5 wires coming out of it...

have you tried pressurizing the intake with air or a fog machine to check for leaks or are you assuming there are none solely based on replacing hoses?

 

maybe a shot in the dark but you said you have S5 mani's. Do you have S5 TB ? doesn't the S5 TB have 2 TPS's. Being that the car is an S4 are you missing a plug to the second TPS ?

 

the S5 TPS's both connect to the same plug

let me know if you figure out how to fix this...and i'll do the same

i think mine is just shitty gas in the tank.....its a fresh jdm swap ...the more it runs the better it gets but it will only idle at 2k after it warms up a bit but if it drops below 2k it dies but 2k and up revs fine...but i can't get it to stay idling on its own if i let the clutch out i either have to give it a sliver of gas to keep it over 2k or it dies
i checked my vacuum lines atleast 5 times now...checked t with a propane torch (but all it did was just burn everything...hahahahaha j/k it was unlit)
i've checked the BAC ,TPS,thermoswitch connector

this start ups first try after 2 or 3 cranks in the mornings when its cold

but doesn't want to stay idling on its own with the clutch out...clutch in it will idle at 2k when it warms up....drivin me nuts lol ....holdin down the OS giken twin disc get sore on the leg after a bit and its not very good for the throw out bearing

 

I havnt tried pressurizing the intake yet, but to answer your questions no my car does not have either the S5 injectors or S5 TB.

 

OK i fixed it. Turns out i had a cracked intake tube leading from the turbo to the MAF, but the crack wasnt visible. I had to put that piece under a lil pressure for it to be seen.

 

Glad you fixed it