Polo M reg 94' Loses power in higher revs

[adamrob69]

hi im new to this site and im guesing im posting this in the correct section!?
iv got a VWPolo M reg which is the first 1.3CL model of the newer shape (MK4 i believe?)

I have been having a problem with it for a couple of weeks now where as at idle and in the lower revs the engine ticks over fine, but when tryin to get over 3000 revs it loses power stuters and in some cases slows down, but if you take your foot off the accelerator and then re-apply it the problem seems to go until you reach the higher revs again. Also this problem does not tend to happen when very slowly accelerating, but when putting your foot down or fast acceleration it loses power.

Have took it to 2 garages, both of which hooked it up to their computers, one came back saying there was a fault with the O2 sensor but cleared it leaving a hall sender fault at the distrubter (Distributer looks brand new from previous owner), so convinced this was not the fault took it to a garage recomneded by a friend and the said the lambda sensor was in fault and could not be cleared. As the CAT is brand new i fitted a new lambda sensor straight away, didnt want to cause any damage to the new CAT, however this has no solved the problem so i would appreciate it to hear you views and/or recomendations

thanks!

[arjunf]

hi - did u ever solve the problem ?

[adamrob69]

yes i did manage to solve this after chucking allot of money at it!! It turned out to be a faulty ECU unit. So had to buy a unit from the scrappy and then a VW main dealers had to fit it due to it being coded to the immobilizer!

[arjunf]

hi - i had a new MAP sensor fitted today (manifold pressure sensor) cost 52 pounds from euro parts - i have driven it around today and so far seems ok as my car was doing the same as yours..... gonna see what happens - hopefully it is ok now

[adamrob69]

where is that sensor located? if it was a sensor issue surely it would of been picked up on VAGcom Fault checking. Is yours the ADX engine like mine? Anyhow if its sorted it no problems. What pointed us to the ECU was the fact it kept giving us random fault codes, and kept giving us fault codes for the lambda probe, which we had just replaced!!