s4 seems to hold back at 3500 rpm

[AudiPete]

Hi all just bought an s4 and it seems to have a problem.
The car has an big power surge up to about 3500rpm then holds back and then at about 4500rpm seems to kick back in again, its not a massive loss of power but its well noticable.The car has done 113000 miles and ive just had the ecu remaped ive changed my diverter valves and changed to silicon hoses, well to the top of the intercoolers that is .

Please help

 

[Broken Byzan]

Thats probably the MAF to be honest, on my normal A4, thats what cured it

 

[Rev-head]

MAF as well take it off and clean with carb cleaner and see if that helps

 

[AudiPete]

Thx for the quick reply I will give it a try..

 

[S4_dan]

get vag-com onto it. My car was doing something similar, now it only boosts to 5psi. this is down to my EGT sensor failing. Been waiting for over a week for vag-parts to send me my new sensor!!!

its also worth while getting a bosst guage fitted. not for the looks but to keep a closer eye on pressures.

 

[AudiPete]

I've had my vag-com on the car and it says theres no faults, Well other than one unknown fault, But this weekend I will buy a boost gauge and see what the cars running. Will it be ok to tap the gauge into the dump valve diaphram side..

And thanks for your help mate..

 

[ZeroK66]

Dont bother cleaning - waste of time and it will never be 100%, just get it replaced. Go for a drive with someone with vag-com, you can monitor the maf reading. Standard should read 215 & chipped should be 250+. I bet yours is under reading badly.

 

[AudiPete]

get vag-com onto it. My car was doing something similar, now it only boosts to 5psi. this is down to my EGT sensor failing. Been waiting for over a week for vag-parts to send me my new sensor!!!

its also worth while getting a bosst guage fitted. not for the looks but to keep a closer eye on pressures.

It turned out to be one of the bump valves sticking open,