Hi all,Just recently put an engine in my s2 turbo and now i can't get it running correctly,the car ticks over fine and drives fine until i hit approx 3700 revs this is when idleing or underload,i have changed the fuel metering unit and had it on a rolling road and as of yet i still have no idea what is causing this,hopefully some of you guys will know !! Thanks in advance Craig

 

What happens at 3700rpm, misfire, lack of power??

First thing i would look at is the hose between the merering unit and the turbo. Possibly soft and deforming under load.

 

It seems to cough and splutter !! I have tried keeping the power on and it does still try to go but it feels like the engine is trying to lift out of the mounts !!

 

I have also tried removing the multi plug going to the metering unit,when i do this the car then drives fine but as soon as i connect back up it goes back to not running correctly !! What is it that this plug does..Cheers

 

That should be the plug for the electronic fuel actuator.. this controls full throttle enrichment and water temp related fuelling.. maybe your fuel computer is up the spout.. i'd perhaps try another one.. maybe you have the wrong fuel computer for the metering head.. there are two types, green sticker and blue sticker fuel computers.. since you changed metering head, perhaps you have the wrong one!!

 

Thanks for that mate,i did not know this

 

Could the tuners that carried out the rolling road session not indicate whether its a fuel/spark etc problem?

The plug as reality says is for the electro magnetic pressure actuator, it enrichens the fuelling for boosting and shuts off the fuel supply on over run. It could be fauly although i'd be more inclined to say its the fuelling ECU playing up.

Do you know anyone with any spares that could lend you a pressure actuator and fuelling ECU, they both are very simple to swap

 

There are two plugs on the metering unit, one for the electro magnetic pressure actuator and one for the flap position potentiometer.