Whenever I start my s4 TII it turns over and idles around 900-1100 every time. I have to blip the gas for a few minutes before it will idle by itself and will shut itself off randomly at idle when at red lights and what not.

Ideas?

 

Does this go away once warmed up? Could be the cold start system that is ment to raise you idle when it is running cold and keep it higher via thermowax but then once up to temp it should settle down. I know mine did that until I readjusted it. The 3k start were it revs up to 3k is electronic from what I have read.

 

yes its electronic, and it's 3500. The neutral switch on the transmission is likely to be broken, or not plugged in. if you start the car in gear it won't go to 3500.

 

He states though that his idle rpm upon start up is 900-1100 which implies that his cold start thermowax mechanism is removed or not working properly.

 

Yep. i said nothing about that, and i thought the original question was why does his car not rev to 3500? not why does it idle at 900-1100.

 

Just means his cold start stuff on the throttle body is either missing or messed up. My dads t2 is the same way you have to let it warm up. I am trying to replace the throttle body with one with the cold start setup still on it.

 

Shoot, the AWS solenoid could be unplugged. Or the sensor at the radiator might not be sending the proper signal.

Using the troubleshooting tree in the FSM is a great way to start.

 

is all the emissions Crap removed?
when that is done,and the engine gets "simplified",you lose your Cold start system and with a Throttle body mod,you take thermowax crap off,and a whole shitload of hoses,so the car won't idle when started Cold, unless you have your Foot on the gas pedal.

 

It does go away SLIGHTLY after the car is at temperature, but not completely. It will still stall at red rights occasionally.

All the emissions equipment is still there, minus the EGR.

Is there somewhere I can get a block off plate for where the EGR is located?

I could care less about the start up honestly, but the car dying out AND FLOODING AT LEAST ONCE A DAY is not only embarrassing, and concerning, but getting expensive. I'm at 130 miles on this tank and I only have a quarter left.

Something has to be wrong. lol

 

You need to check the BAC and you also need to check the idle rpm when the car is warmed up as it should read 750 to 800. You can disconnect the plug to the Air Bypass valve which is supposed to be responsible for the high idle rev upon start up and it will still do it because the BAC if working properly will see that it occurs. Now if your car does not do the high idle rev for 17 seconds upon start up then that means something is fishy with your BAC.

 

Would that also contribute to my more shitty than normal gas mileage as well?

 

Likely not. A failing O2 sensor would contribute to poor mileage.

 

o2 sensor on the dp is brand new. But thanks for the help guys. I'll try everything suggested tomorrow

 

While it is brand new does not mean the wiring to the ECU is up to par. There are different ways to check this but taking a measurement at the ECU is one of them. I am not saying the wiring is bad but just pointing out the possibility.

 

jus warm the car up before you drive it, why would you want the aws anyways?

 

Something that may not be in the FSM tree - Check the tightness of the throttle cable, I killed myself for too long when I first got my FC why it was dying at stop lights all the time, then i realized there was no tension on the cable. This won't solve your cold start problems but always a good thing to check the cable tension along with everything else on the throttle body while you are poking around.