I recently swapped an s4 turbo engine into my s4 N/A. The turbo engine has great compression and is getting fuel but it wont start. It also has spark and timing is on because it has started for about 30 seconds before. I am starting to think it is the ecu because when I unplug it the engine spins over like it does with the ecu plugged in. Is there a way I can check to see the ecu is working? I have also checked the ecu grounds and they are all fine. I labeled the harness before I swapped the new engine in just so I would know where everything went. The engine has had the rats nest removed and other than that it is stock. It has new plugs and wires. The engine has sat for several months so I figured it would be difficult to start but not like this. Also if I unplug the maf should the car be able to start? Any help would be appreciated.

 

Should I just try to pull start the thing? It gets really flooded out now and I think that adds to the problem.

 

bump

 

you took a t2 motor and put it in your na? did you use the ECU from the t2 also. did you swap everythign the t2 engine needs?

 

Re-examine your turbo inlet duct. Make sure it's clamped to the turbo and the afm. Then make sure you remembered to install the silver checkvalve in the backside of the turbo inlet duct and the air bypass valve is also plugged in the back of the turbo inlet duct.

Your car has the traits of an open hole/large air leak. Plus make sure you plugged the afm's plug on.

Did you make sure you put the brake boosters feed line on the back of the throttle body/intake manifold???

You should make sure the maf is installed. A non turbo maf will work if you don't have a turbo maf. At least for starting purposes.

Did you remember to buy a turbo boost sensor?

 

I have the tII ecu the boost sensor and all of the electronics installed with the engine. I have the brake booster hooked up as well. The silver check valve is what I dont have. What is the silver check valve for on the back of the turbo inlet duct for?

 

bump

 

It's for crankcase emissions. The hose from the checkvalve goes back to the oil filler tube. The idea is to make sure the hole in the duct is blocked off to prevent a air leak and a non-starting engine.

It's shown in the online fsm. Its in the fuel section, last few pages.