So i just swapped an s4 t2 motor into an s4 na chasis. I got everything hooked up right by following the swap threads. I'm using the original t2 harness that came from the car and everything. It starts up right away every time. After the cold start it has a really crappy idle and when you rev it up a little it doesn't seem to hold idle after that. Here' a video of it. Aslo a bunch of warning lights stay on and my shift lift on the cluster. There aren't any buzzing noises either. I cleaned a lot of grounds as people have told me it was bad ground and i also got my alternator checked and it's running fine too. I'm using a red top optima battery.

 

Jumper the fuel check connector and see if this helps. You could also have a vacuum leak.

 

i'm kinda new, so what is the fuel check connector? I checked for vacuum leaks and doesn't seem to be any but i'll double check again.

 

I knew you were going to ask that. There is a Yellow plug shrouded in a Black ruuber boot that is part of the Emission Harness located on the passenger side of the engine. Same harness that the Boost Sensor feeds off. The plug has two wires, one Brown and the other Black. Jumper these two wires to each other.

 

ok, what'll happen or might happen if i do that? or like what should it do?

 

Would you believe cause the engine to continue to run?

 

well i guess i'll go try it when it gets cooler and see if the car decides to stay on.

 

Don't you need to run a power wire to the alternator as the TII harness on an N/A Car doesn't have any alternator wire?.(Satch?)

 

If the Engine harness from the turbo was used it would be used to connect voltage to the alternator via thew B/W wire in the two wire alternator plug. The B/W wire of the Engine harness would connect to the Front Harness. On an NA the Front Harness from the Engine fuse is connected to the Emission Harness instead of the Engine Harness.

 

What about the ECM? Did you swap it too?

 

Didn't know s4 TII has Electronic Counter Measure system as a option in the 80s.

Just trolling

 

Still wont hold idle -.-

 

Does this car still have the cold idle thermowax and idle control valve?

 

Hurm, I kinda had this problem on my s5 vert when the ECU brunt out and took the MOP unit with it. Car would start fine but wouldn't go past 3k unless I slowly raised the RPM's. So not sure if that is the case with your car since it's an S4 and not an S5.

 

I don't think that's the problem. I can go way over 3k and actually drive the car normally and actually step on it

 

The idiot lights being on are suggesting there is something w/the alternator. You can have it checked all day and that does not necessarily mean it is good. How about unplugging the two wire plug behind the alternator and grounding the White/Black wire (the other wire in the plug is Black/White so please don't confuse the two). After the W/B wire is grounded turn the key to on and most of the idiot lights will turn off besides the parking brake light if it is engaged. If the idiot lights are now off as opposed to being on then this points to the alternator being iffy. You can also check the voltage output of the alternator while idling w/all the plugs connected by taking a voltage reading of the large Black wire/cable bolted to the side of the alternator. While idling it should read 14 volts. If it is too low it can affect the goings on inside the ECU which will then affect the ability of the engine to run properly.

 

thanks for the suggestion. I'll go try it later and see if it works.

 

I made a typing mistake and meant to say when the W/B wire is grounded w/the key to on the idiot lights will turn on. When the W/B wire has voltage on it, the lights then turn off. The alternator only places a ground on the W/B wire (turns lights on) during two different occasions and the first instance is w/key to on and the engine off, while the second instance would be w/the engine running but the alternator failing as a faltering alternator places a ground on the W/B wire which turns the idiot lights on. So, a properly running alternator should not be grounding the W/B wire while the engine is running.