80 Tdi loss of power under load

[frainj]

Hello everyone. I've just joined, so please forgive me if this question has an obvious answer I don't know about.

My 1995 80 TDi Avant loses power under load, such as when going up long hills on the motorway (speed will drop down to 70, no matter how much throttle I give it.) It's not exactly a ball of fire on the flat either, and I'm sure performance isn't as it should be. I've replaced the air flow meter, as that seems to be a common solution for power loss problems, but it made little or no difference. I don't know if it's significant, but the power problems seem to be happening around 2000rpm in 5th (or 4th if going up a steep hill), and there's generally quite a bit of black smoke chuffing out the back when it happens.

Also, does anyone know if the 80 TDi requires an 8 or 10 pin plug for an 'ebay special' tuning box? I know they're not the best way to gain performance, but I've been in a Seat Leon with one fitted, and it really made a difference.


Any suggestions would be gratefully received.

Thanks
John

[ini]

I think your car will have the 8-pin fuel pump connector.

You need to check for fault codes with vagcom or similar, you may be overboosting?

If your MAF is not at fault, and you are getting black smoke when you loose boost, then underfueling is probably not the issue.

Check wastegate operation (fouling & spring etc), also check the n75 and boost control hoses.

Ensure your air filter is good, and there are no obstructions in the airflow.

Ensure fuel and engine temps are reading ok.

Also change the small section of hose to the circuit board pressure sensor, which is located inside the metal ECU body. Also blow through the tubing from the ECU to top boost hose to check for blockages.

[midskev]

hi ini

i have the same problem and a cpl otheres at the moment, is it easy to change the pipe inside the ecu before i take it off n start looking around also where does the pipe run to!!! i cant find it lol iv replaced every other vaccume pipe i can find, and the fuel return pipes as they where rotton as el lol

any help would be wellcome

kev

[ini]

The early TDI's have the MAP/pressure sensor inside the ECU, on the circuit board. (as opposed to on or around the intercooler on later models)

You have to disconnect the battery, and leaving the ECU harness connected, undo the 4 small torx screws and open up the metal ECU body.

Inside you will see the small black rectangular 'circuit board' mounted MAP sensor, which is connected to the nipple on the inner ECU body with a 2 inch bit of thin dodgy tubing.

This is the correct tubing to replace, as it degrades over time, it is held on by 2 small clamps, and is easy to change.

[midskev]

thats great thanks ini ill look into that at the weekend well get me out the house eh lolol

cheers mate