any thoughts ?? MK4 GTi AUM

[Karbonetix]

Hi Guys

  Owned the car a couple months now, has always felt a bit hesitant, took it to a tuner, found a couple troble codes, pressure drop beteen throttle valve and turbo and sytem too rich bank 1 !

  Engine was found to be creating a vacuum effect, im told the valve cases this, so booked it in, got the valve changed followed by some pipework that crumbled, was also advised the wiring to the coil packs was in bad condiition so new wiring was ordered and had that done too as this was the most likely result of the misfire !  the wires were cracked etc and were quite bad....

  So, got the car back, no codes in the system, seemed to drive smoother but still really lacking on boost, infact my 110 GT TDi boosted better and felt stronger, this car is running a 180 map so i would have though would pull quite well ! My misses has a 130 GT TDi and its quicker than my GTi 

   Ive fitted new plugs, still no change and now the code is back for the valve pressure drop again ! which has been replaced with new.... could i have a boost hose leak ? cant think of much else ! got it booked in again next friday, its doing my head in now, the misfire is more of a hesitation than a misfire, it also over revs on gear changing frequently at higher RPMs

  Any suggestions would be much appreciated

Cheers
J

[WadGTI]

I would be scanning again, listing all codes recorded.

Standard things that I would look at, check inlet for the injector seats leaking, change the fuel filter, get a spray bottle of soapy water and spray the hoses under idle to see if you can see the water bubbling (i.e. vac leak).

[topher]

a smoke test could help if it is a genuine pressure drop the ecu is detecting. if its an aum the boost pipe at the back of the engine is common to leak. could be a few different things to be fair you could always pop it over to us in cannock if you get stuck.

[Karbonetix]

Thanks for the advice guys, scanned it today with my hand held, p0411 is a new one,injectors issue, whilst driving now the fuel light keeps coming on and beeping and the gauge drops regardless that it has a quarter tank still !

i was told by another garage the misfire was the wiring to my coilpacks so got the wiring all replaced, not looking like it was that at all as the hesitation was still evident, looking more and more likely to be an injector issue... frustrating... RE the pressure drop, same garage replaced a valve that they said was the issue, same fault is back though...

May have to pop over to you guys a midland as i need my car... besides gives me a chance to show off the kit ive designed and done lol

possibly a silly question but ball park figure if it is injector issue ?

Its never run right since ive owned it, embarrasing when my misses 130 gt TDi blows by me when im running a 180 map lmao 

[clancy]

The joys of the mk4

[brianpologti]

I would get it over to them, as lease they know what they doing with vw's and not poking around in dark, prob save u money in the long run,

[Dalo Harkin]

from what you have said in terms of hesitation, you want to be looking at MAF, throttle body, spark plugs, coil packs themselves (yes the wiring can go) but I've had a coil pack be 'dodgy' if it goes completely the car sounds like a Subaru (best way to describe it)

you need to also have a look around the PCV system for leaks (the plate under the manifold where the N249 and N112 are located is like a maze of pipes)

[lamplighter]

Hi just seen your post from some time ago just a thought with your aum my old joty had the same issues

take the map sensor out give it a clean put it back  the pressure drop problem code i had was down to the ecu wasn't an actual fault  so got it recoded by vw and the car was like new again  .