N75 Help

[jonnyblease]

Hi,

Basiacally my cupra which has been mapped and has a panel filter is hesitant at half throttle before it comes onto boost and just during. If you fully accelerater it pulls no problems. It also apparent when letting off the acclerator very suddenly and holding a half throttle. The problem is a little intimitent. It also does it when the engine is cold. It feels like the engine is being held back.

I have recently found out it has a N75 F valve fitted to it, just wondering after reading alot about them whether this is the source of the problem? what valve do most people reccomend with these kind of mods.

H
J
or ECS valve


Thanks in advance

Jonny

 

[-=Rob=-]

Jonny - The standard valve is a type C, however I've read somewhere that the F is the same valve and a replacement part for the older C which isn't available anymore. The H, J and ECS race valves produce different boost characteristics and have not be used for any standard map or re-maps on the Ibiza, I would stick with standard although others have, and probably will say otherwise that the H, J etc work ok...

Have you checked your vac lines, making sure none are perished and leaking, this could cause you problems? Do you have an aftermarket dump valve, take this off and make sure it's well greased and holds on a pressure test, if it's a Bosch one, get it swapped out, it could be failing...

 

[jonnyblease]

Thanks for your help mate,

iv had a brief check of vacumm pipes and cant find any that are leaking. It has a forge recirc valve on it at the moment. Its just strange becasue its fine when you plant your foot to the floor just fells like its being held back and is jumpy when you have half throttle especially when its cold where i tend to use as little throttle as possible for obvious reasons!

Could it be a coolant temp sensor?

Thanks again

Jonny

 

[-=Rob=-]

No probs - You could try a throttle body alignment, if you don't have vag com I think you can force this by disconnecting the battery for 10mins and re-connecting up. Turn ignition on and wait until you hear the TB align stop.

 

[jonnyblease]

I think i have basically done this when my battery died at the weekend and fiited a new one and it made no difference.

Do you think giving them and the sensors a clean will help?


I think i am going to get one of these;

http://www.awesome-gti.co.uk/product.php?xProd=10705&xSec=1

Might help me diagnose the problem, anyone had any experience with this or something similar?

 

[-=Rob=-]

It may be due to your re-map, I've had a couple of 1.8T's that have been mapped and once done it does introduce less smoothness and occasional jerkyness when on light driving.

 

[jonnyblease]

i have thought this but it is a little frustrating, iv got it booked in to have vag com done on it on monday as i dont have any of the software

 

[-=Rob=-]

You can get yourself a cable from Ebay for around a tenner and diagnose with the free sharware version, you'll just need a laptop or USB extension from your PC. SHould be cheaper than paying for diagnostics. Alternatively there will bound to be forum members in your area that could offer a hand

 

[jonnyblease]

Thanks again for your help


Could be a plan, anyone got any VAG com software around the manchester area