Hi guys, i am having a very stressful problem, i have a 1.8t B5 A4, 1996, it has a new turbo and a new Recirculation valve on it, all pipes are new and uprated, but when i am accelerating the car works but it sometimes gets a sputter on the boost build up and makes the car start jerking about but then it seems to work sometimes its very anoying because i go to over take and the car pulls forward then has to drop back as it wont boost properly, im running manual boost and 14psi.

any help will be very apprechiated.

 

You shouldn't be over 12psi on a manual controller without a tuned ECU. Turn the boost down and see what happens. Also, did you gap the plugs down for the higher boost?

How do you have a 96 1.8T? They started in 97, at least here in the US...

 

Boost controllers on such small turbos will make them studder and not hold properly like that. I would take the boost controller off and run it off the n75 and that should fix your problem.

 

Thanks for replys, Erm I forgot to mention it is chipped and its been on manual boost for about a year and half and its been fine till couple of months ago, and it is a 96, I'm in UK mist be different, what do mea about the spark plugs, please explain, I did read about upgrading them would help but I don't know much about that

Thanks mike

 

The stock plug gap (at least in US-spec cars) is .032". When you raise the boost, higher cylinder pressures require you to gap them down to .028" to keep from blowing out the spark. Try that gap on a new set of plugs and see how it responds. Chances are your plugs were eroding and effectively increasing their gap beyond the .032" you've had them set at. Low boost probably has allowed them to work but once it really comes on hard, the plugs may not be able to fire effectively.

 

ah thanks mate, that makes sense, i just ordered some NGK i have read about on here, so i ill try them when u turn up and see if they work for me. thanks for the help

 

hi again, i have tested the new plugs, when they arrived i measured them and they were 0.28"/0.70mm, so i put straight in, it works well but every now and then does the same thing but at much, u think i sould adjust them even closer say 0.18"...... thanks

 

No, .7mm is where you should be.

Do you have a boost gauge? Do you just feel a lack of power or an actual studder? I wonder if you could be misfiring.

Have you ever seen the check engine light flashing?

 

ok so the 0.7mm is ok, and well it runs fine most of the time but its an actual shudder, and it jerks about but its a B***h when im trying to overtake then it shudders and i cant so i have to drop back, and yeah i have a boost gauge, im running about 10psi give or take. i used to run 18psi about 8months ago and then i brough a new turbo so i dropped it down and was ok for a long time and now its doing this. thanks for the reply

 

and the engine light i have never seen light up, so i am thinking someone might of takent he bulb out of it....