UK MY99, fmic, tek3 remapped
Friends car running what feels like limp mode. Wont rev past 3500-4000rpm or near about on wot. Boost pressure also feels as if its been restricted.
Diagnostic check via black connectors shows no fault codes?
Other than that car runs fine, no misfires, idles fine.
As precautionary new MAF sensor has been fitted and still no change.
Tried by-passing the ecu boost control by running direct actuator pressure, car then runs fine all the way to the redline. Obviously its not getting the full boost pressure.

Removed the dv and blanked/plugged the hose still no change.
Cleaned boost solenoid, which is ticking fine.
Map sensor swapped no change.
Hoses which where difficult to check seemed tight and good but not 100% checked. Mind you if there was a leak in the fmic hoses the car should rev past 4000rpm but just feel like a na engine. Well that's my theory anyway.
Oh and speedo is working fine.

Could do with some input from members who may have experience this problem.

Ticky

 

Had this problem on my MY99 a year ago, limp mode 0.5 bar boost and i took it to the mechanic after having a look at it first, had select monitor on it, showed no faults all voltages was ok, we changed maf no luck, checked all turbo pipe work for leaks etc, nothing it just wouldnt go out of limp mode, i then had to drive to work and parked the car, came back after 6 hours and started and had full boost again and full power

cant really tell you what i did, only thing was it was cooled down and left for hours and then no problem

 

bad fuel ? have you tried a reset on ecu ?

 

I dont this one will cure itself as its been like this for a week.
Fuel is a possibilty but never heard of it going into limp mode for bad fuel.

Will be trying a bleed valve once a boost gauge is sorted to see what happens then.
Cannot remember if my friend reset the ecu once the new maf was fitted. Will have to get him to do it to be sure.

 

mine had those symthoms for 3 days i think, needless to say i was very pleased that power come back to normal, especially when you havent got a clue what the fault is

bad fuel or lower grade octane would just retard the ignition, not put the car into limp mode i think, besides i did not empty my fueltank and refill it

very strange, it could ofcourse be that we had fiddled with hoses and maf and other sensor connections, but hey it was still limp mode when i drove to work, and then mysteriously i had full power again

If you havent already done so you could try reset the ecu

good luck with it anyway