BAC Valve
 

On my engine, where the BAC valve and air control valve are supposed to be there are block off plates. The air bypass valve and check vavle are gone also due to the car having an aftermarket intake. Where should I route the vacuum lines that used to go to them too?

You don't need the BAC hose if you don't have the BAC.

Search. There are plenty of vacuum diagrams and vacuum/emissions/BAC removal diagrams as well.

Would I just cap them off?

Turbo or non turbo?

Turbo. Would I be better off putting all these things back on the engine?

The ACV on a turbo car has three *vacuum lines*. Only one hose is actually vacuum and it needs to be plugged or capped . The other two are not vacuum and nothing needs to be done with them.

The attached jpg is NOT my engine but a jpg captured off this site. You can try to tell what he has done with the BAC removed by looking. Seems he capped off the intercooler and the pipe just near where the BAC was.

That is basically how mine looks. The car doesn't crank good when it is cold. Once warmed up it will crank first try. I was thinking with these being removed they would cause that.

Hard starts when cold but good starts when hot is an indication that the water thermo sensor on the back of the water pump housing is not connected up or for some reason the signal is not getting to the ECU.

When the ECU does not see this signal, it creates a default signal for water temperature. That default temp is approx 180*F. This results in the START FUEL MAP internal to the ECU delivering not enough fuel for a cold engine.......but also results in good starts once the engine is warmed up because the default temp of 180*F is close to what a warmed up engine temperature is.

This signal can be seen at the ECU if you backprobe the signal wire with a digital meter. The FSM section called CONTROL UNIT lists what each wire at the ECU should read with a fully warmed up engine.

Or the water thermosensor might be good, but your ECU is missing the START signal to the ECU from the START circuit that turns the starter solenoid over/on. Either will result in the same condition. So if someone has modified the start circuit, that could be the problem i.e. eliminated the connection b/t the starter and the ECU. I'm not saying the ECU has squat to do with the turning over of the motor, just saying that if the ECU does not know the engine is being started, then the ECU will use the AFM for fuel during the start sequence instead of having the start fuel determined by the internal fuel START MAP inside the ECU. The AFM will deliver too little fuel if it is used instead of the Start map internal to the ECU. Especially if the engine is cold.

Ok thanks. I will definetely check that. Sounds like that is a good possibility. If it makes any difference, once it finally cranks it won't hold idle until it is slightly warm, and to make it run I have to tap the throttle I can't hold it steady or it will start backfiring and try to die. While doing this everytime it tries to come out of vacuum when it won't idle on its own it backfires and tried to die. After about a minute of this thought it idles fine but high at around 1500 to 1900 rpm.