Well I must admit I was thinking along similar lines....switch flopping up and down?

 

I was digging through the memory bank and remembered a friend having a cut out or misfire issue on his mk4 golf 1.8t many years back...he said at the time it was either a bulb or a switch. I looked through the googleweb and I see it comes up now and then....even on here.

 

My local TPS has them for 11 quid plus the vodka and tonic so I'll get one winging its way towards me later....thanks for the heads up.

Well...I bit the bullet and bought a new genuine switch thinking the same...sounded logical enough.

 

However the only thing it's achieved is it's one less part to wear out anytime soon like all the rest....the fault still persists.

 

I'm thinking fuel pump next....not had one of those yet!

 

The only thing original soon will be the body shell at this rate!....I'm still smiling though....just.

New fuel pump fitted....still the same.

 

Hi

 

I had this problem with mine and I did excatley the same as you fitting different parts and it turned out that the person I brought the car off had it remapped badly so I got it remapped property and all I can say is wow what a difference my hesitation not there anymore and also I get a lot better fuel economy I hope this helps you 

I have wondered if that maybe the case but there was no mention of it when I bought it, and most like to claim so if it's been done.

 

If anything I think it's worse since changing the fuel pump...there's a harsher hesitation now and it feels like it's hitting a wall harder sometimes when lifting off the throttle which is either a coincidence or whatever the fault is it's getting worse.

 

I maybe able to get a std ecu to try that's had the imobilisor deleted so will see what that does.

It hasnt necessarily been remapped just that part of ecu has gone bad.

A friend had similar on a mk5 gti that had been stood for a while.

 

He drove it home and then did what needed doing tyres, brakes, etc.

First drive and it died.

Ecu had given up, 2nd hand ecu and some coding and . . . Roberts your mothers brother all good 

That's the direction I'm thinking now before I type out a spares or repairs ad.

Well....we think we've found the fault....anyone want to take a look at the thread and take a guess...it's not on the list and I bet nobody gets it!!

Sticky wastegate?

Nope....

 

Servo hose....just where it goes into the none return valve (near where it passes under the maf) there's the smallest of cracks in the plastic pipe.

 

My mot man found it....ears like a bat...bloody youth lol!!

 

So 50p worth of tape (And 20 year younger ears!) scores victory over a pile of parts. Instead of hesitating it's way to 4k it now comes on strong off the throttle and breaks traction which it's never done before.

 

So once I replace the temporary repair with a new pipe there could be some more hp on the horizon....well the exhaust is getting past it's first flush of youth and it would be rude to replace it with a std one, then I'm sure that pinched TIP must be corking up the airflow a bit and.....

Could you take a photo of that bloody pipe? This surging is taking me crazy, have it also... its the only fault which i was not able to sort /code out.

Looks like the part number is 1J0 612 041 BS. A quick Google search and there's a few available on eBay in europe. Also looks to have been a known problem/recall....bloody thing!

 

Nope, it won't show up on any scanner or a smoke test, so certainly needs highlighting more as it's certainly not an easy find to diagnose.

 

Mine has split just under the none return valve, hence not showing on the fabled smoke test.

Make this sticky? I think the hesitation before 4k is present on almost all older AUQ engines now. Goin to examine this tube on my black lady tomorrow.

Edited 19 January, 20197 yr by iXtremist

I'd say....I changed all the parts in the thread for no reason. There could be many owners out there waisting time/money/ frustration when a £35 hose will fix a problem that hundreds didn't.

I see it's a know fault but no mention of anyone having the pre 4k hesitation I did.

The moral is nobody knows everything or has come across evey problem so some issues go either unfixed or good cars get moved on or broken out of frustration...I was close after chasing the fault for 3 years....I just like the car too much to have given up but it tested my patience that's for sure.

 

Have a good look around the back of the pipe....that's where mine split so not visable from just looking at it. Check around where the pipe pushes onto the non return valve.

 

I’ve just changed the brake vacuum pipes on my VRS, one pipe on the check valve was completely split and a few of the other joints were pretty rotten so ive replaced them all 

 

 

Good call. Did you have the pre 4k issue I had (in this thread) or just noticed them/heard them leaking?

I was chasing a 17705 fault and found it then 

Edited 19 January, 20197 yr by AndrewRoberts

Ah ok. I never had a code on mine...on 3 different scanners inc vag com. I guess yours is running ok now?

Edited 19 January, 20197 yr by JMvRS

It is now, I also had to change all the crankcase breather pipework and clean the throttle body 

 

This is the mess the previous owner owner left for me 

 

Edited 19 January, 20197 yr by AndrewRoberts

PCV + hoses after 300k km.

Changing the PCV is strongly recommended every 60k km..

Yea they rot out pretty quick really. At least your elbow came out in one piece, mine snapped off in the oil filter housing and was a complete pig to remove 

Mini update:

 

Since fixing the servo pipe on mine it's running great!

 

Averaging 85-90 miles on 20 quids worth of super unleaded under normal short journey use....3 miles home to work a day plus return and similar a couple of times a day on and off for other trips....should be decent on longer runs....ripe for a bit more umph now

I finally find out the reason of hesitation before the full turbo boosting...

IT WAS THE FUEL PUMP.

I run the logs and from injector duty cycle + A/F ratios it was clear that there is not enough fuel during the powerspike (combination of tune + race N75) around 3300RPM. So i replaced the fuel pump module with Walbro unit capable of 200l/h (also as preparation for next mods) and booom. No hesitation trough whole rev range + more power at top end + it can spin pilotsport 4 s 18/225 tyres at second gear at launch very hard😍. The old granny fuelpump have seen better times.

On 27/03/2019 at 19:02, JMvRS said:

Mini update:

 

Since fixing the servo pipe on mine it's running great!

 

Averaging 85-90 miles on 20 quids worth of super unleaded under normal short journey use....3 miles home to work a day plus return and similar a couple of times a day on and off for other trips....should be decent on longer runs....ripe for a bit more umph now

I've been having very similar issues around the 3-4k rpm mark too. Especially in 3rd and after longer distance runs. Changed nearly everything.

Gonna check this when back off holiday. Fingers crossed.

On 25/07/2019 at 10:00, iXtremist said:

I finally find out the reason of hesitation before the full turbo boosting...

IT WAS THE FUEL PUMP.

I run the logs and from injector duty cycle + A/F ratios it was clear that there is not enough fuel during the powerspike (combination of tune + race N75) around 3300RPM. So i replaced the fuel pump module with Walbro unit capable of 200l/h (also as preparation for next mods) and booom. No hesitation trough whole rev range + more power at top end + it can spin pilotsport 4 s 18/225 tyres at second gear at launch very hard😍. The old granny fuelpump have seen better times.

Interesting, I fitted a cheap pump just to see if there was any difference but didn't help with the then issue. However, I'm not so sure it was as good as it was on the O.E pump so may swap it back as a last ditch attempt before I throw in the towel.