ok so after rebuilding a jdm engine and swapping it in and a few hiccups it runs pretty good/great. there is now 300miles on the engine and now it dosnt have any power from idle to 3000rpm it will just die if your not careful. once it goes past 3k it runs fine and pulls hard. at idle and until 3k its sounds kinda funny and has a good amount of vibration.

it still needs a tiny squirt of oil into the housing to get it started. by now it should be able to start on its own right? my brother said he got it to start on its own quite a few time but i wasn't around.

my brother and i have check TDC a dozen times its perfect, timing is good. new plugs and wires. checked TPS cold and at operating temp, its good. runing 93 on stock fuelpump, have a bigger pump that i havent put in yet. waiting to get bigger injectors and standalone.(waiting for engine to get to at least 2k miles.) only thing we haven't checked yet was compression. on the to do list.

Mods.
Stock ECU/intercooler.
Injectors are freshly rebuilt. stock
BNR stage 2 turbo
RB REVII exahsute.
Turbo inlet pipe.
Deleted splitter tube, air pump, air control valve.
RB aluminum Double Sheave Main pully
and a BOV... That doesn't work.
ACT 9lb flywheel, and rear weight.
ACT Clutch

thinks thats all.

 

How does the engine behave if you were to rev the car while idling? The same? The primary injectors work under 3800 rpm before the secondaries turn on and the TPS plunger is fully extended above 3000 rpm. How did you test the TPS?

 

when ideling it sits steady at 750-800rpm but it feels rough, and some vibrations. all the way to 3000.

dont know my brother did it, test with some circuit also a voltmeter, wasn't around for it.

my brother and i have no idea whats going on and we are stuck. but it has to be fuel right this is what my senses are saying. we have spark, air, and timing so whats left is fuel.

ill check tomorrow if the tps is fully extended. i am 99% sure it is though.

 

On an S4, pin 3E and pin 3C at the ECU should both have battery voltage w/key to on. If either doesn't then the injector plug is not firmly attached to that primary injector which "might explain your problem. With respect to the TPS, I mentioned the plunger position because above 3000 rpm the TPS no longer receives input from the throttle position and is locked into a full throttle mode, but until it reaches 3000 rpm the TPS sends info to the ECU. Since your problem occurs under 3000 rpm it "might" be another thing to look at. The TPS's Green/Red wire should read 1 volt w/key to on and the engine as warm as possible.

 

Ok, so here is a little more info on what is going on. The car will idle at 750 once it is warmed up. I can rev the engine without a problem when no load is applied to the engine (ie. sitting in the drive way). No hesitation and yes some vibration but i think that that is due to the brand new motor mounts. The problem start when you go to move the car. I think the issue is that when load is applied to the engine, it twists the engine ever so slightly and is creating a vac leak somewhere (most likely the intake tubing). I haven't had the time to sniff it out w/ some propane. That's on the to do list. The car does not really pull much better over the 3K point. So if you guys have any more insight on the issue, please share. Thanks!

 

For starters you can check for battery voltage on the two secondary injector ECU pins w/key to on.

 

Hmm buddy check your batteries/ and see what speeds is that starter cranking at.
Did you change the injector grommets?? Possible vac problem
Also clean the studs onto which the Primary Ignition Coils get grounding on..