i wanted to be more like you guys

Matt82

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ive recently bought a mk4 golf off one of members from CGTI. its a 2000 ARZ, 148k miles and all in all it seems pretty good.

i gave it a bit of a once over today because i could feel all wasnt well with the new acquisition.

firstly the car had quite noticable lag, ie on par with an escort RS turbo from back in the day and a 20vt aint meant to be like that.

so tonight i had 15-20 minutes, i had a quick dive into the engine bay as i had a few ideas, firstly either a big boost/vac leak or DV not sealing.

i knew the rough principals behind the N249 (ecu controlling DV mechanisms) and decided id rather just have the DV controlled by vacuum. a couple snips and a new vac line later the dv is being controlled as nature intended (i will read more into it incase there are going to be side effects)

then i jumped on the uber typical breather hose splitting causing a boost leak. sure enough that was code F but without a replacement i snipped that too and stuck a bolt in it.

vac line to the fuel pressure reg wasnt the best so that was replaced with typical 3mm id black silicon + a shot of oil syringed into the FPR.

immediately the car feels different (and improving with every mile, adaptation i suppose). now the torque responds as soon as you hear the turbo and once on boost properly it has a fair bit more shove than before. i recon the missing mpg will come back pretty fast too.

any idea where the MAP sensor is on an ARZ? (it may be the same as an AUM i think)

tomorrow ill test the DV to see if it does seal properly and then ill test the lines for the N75.

currently my breather doesnt connect to my inlet manifold. due to a one way valve that only funcitons on closed throttle anyway, but the rest of the breather is still connected to the airbox. is this sufficient or do i really need to reinstate the OEM breather settup?

injector seals are leaking boost too. is this a big issue? will i gain much by recifying that in your experience?
 
MAP sensor should be in the top of the SMIC IIRC, I would change the injector seals too as this will be a vac leak off boost as well as a boost leak...

<tuffty/>
 
sir yes sir. ill get those seals arranged then.

when i get a chance (and access to a proper compressor) ill get the boost leak kit connected up and see whats what but doing the breather and n249 has brought the car much closer to how it should be already
 
sir yes sir. ill get those seals arranged then.

when i get a chance (and access to a proper compressor) ill get the boost leak kit connected up and see whats what but doing the breather and n249 has brought the car much closer to how it should be already

Good stuff. The N249 valve was such a pants idea.... On a par IMO with the SAI system.

I would reinstate the OEM breather configuration personally. OK, it's not the best design, and they break, BUT, they are there for a reason.
Bear in mind that (if the hose is the one I think you mean - 'z' shaped hose under the inlet mani), they aren't cheap from Audi. Around or about £25 IIRC.

I made my own - and it is spectacularly bad I must admit - but it works.... For now.
 
yup, z shaped hose. has perished and burst.

as for the breather, i should reinstate it. shame they charge so much for that hose and i am tempted to leave it open as under all conditions the block is being vented to the airbox anyway which is always under vacuum. a lot of people just bodge a silly filter onto the end
 
yeah, with old age they do like to stick. ive come across a couple in the past which have caused serious head scratching as people wonder why it goes leak and timing gets knocked back

just a small drop in there can bring an FPR right back to life. can show you before and after dyno plots of a car which had a sticky fpr
 
OK, funnily enough, after the PCV inlet mani hose discussion - my home made billy bodge of a hose (and it is god awful) has split....

******.
 
gutted the MAF yesterday and i had a paper AND foam filter. ripped out the foam

mk4 is getting pretty quick now. need to mod the wheel arch liner and i think ill leave it at that

oh, and injector seals innit

pulled the plugs out lastnight. bright red haha previous owner loved Millers