Boost issue

[8bit]

OK, so just to keep the thread up to date...

Took the car for a run today, tried it with the MAF connected and then with it disconnected. Generally speaking both are pretty much the same. In 2nd gear from closed throttle straight to WOT there's *almost* always no/very little boost below about 3200rpm, then it boosts in a big surge, as it was doing before. In 3rd it seems a bit better, it builds boost from about 2200 up to full boost by about 2800, just as the car always did in all gears. 4th is much the same as 3rd.

Sometimes when cruising in 5th or 6th if I floor it it's very slow to build revs and the induction noise doesn't change until either it gets to about 3200rpm then full boost all at once like in 2nd, or if I close throttle then jump right back on it it builds boost correctly from about 2200rpm or so.

As above I tried with and without MAF a couple of times each and to be honest I can't tell much difference really but I'll need to get it logged to be certain there's nothing wrong with the MAF obviously. I've put a VAGCOM request in the appropriate forum section, if someone can help out then I'll get the TB reset again as I know the garage that had it last don't have VAGCOM (some other software) so the TB reset may not have been as good as VAGCOM's method.

Any further thoughts most welcome

 

[8bit]

Bump - anyone got any ideas?

 

[traumapat]

remap. get a custom one so they can set the levels whilst checking.

 

[8bit]

My car isn't remapped just now, it's the standard map. It hasn't always been doing this either, it's a recent thing.

Or are you suggesting getting a remap to try and fix this issue? To be honest given this is a fairly recent issue I'm not convinced it's going to help. Also I can't justify spending a few hundred quid on a custom remap which might not fix the problem, particularly if the problem might be the turbo, a remap would place greater stresses on that and the rest of the engine too which might make things worse surely?

 

[leon cupra r]

could always try a revo 5 hour trial niall?

 

[8bit]

I see what you're saying but I don't want to introduce new things, something has caused this to develop on my unmapped car and I just don't want to complicate things by introducing new factors right now. I've also read a few posts where people have said when the trial expires the map it defaults back to isn't as good as the real OEM map that was there before...

 

[gezmeister]

Didn't know that. I had the revo trial on mine, and it was brilliant. But as you're saying, remap probably isn't the best idea as a fix

 

[traumapat]

The idea is it will become obvoius during mapping and tracked down if their any good. youve tried the majority of things to no avail and you want the map anyway. hand it to a decent mapper and tell them to fix it

scrap the thought.


What happens from closed throttle progressively opening so you dont hit WOT until 4.5k? Does the turbo come in quicker?

Are you happy the TIP is in good condition and not collapsing?

You need a friend with vagcom or buy it, you need the tbr done. It could be that simple

 

[8bit]

The idea is it will become obvoius during mapping and tracked down if their any good. youve tried the majority of things to no avail and you want the map anyway. hand it to a decent mapper and tell them to fix it

scrap the thought.

Tempting, and in an ideal world I'd do just that but for a start it's not financially feasible as it's the long pay month after Christmas and my road tax, MOT and insurance are all due in February. Also I live in the middle of nowhere (Aberdeen) from the perspective of options of tuners.

What happens from closed throttle progressively opening so you dont hit WOT until 4.5k? Does the turbo come in quicker?

Haven't tried that but I've got the day off tomorrow so will give it a shot, thanks. What might that imply if that does happen?

Are you happy the TIP is in good condition and not collapsing?

You need a friend with vagcom or buy it, you need the tbr done. It could be that simple

The TIP is a THS Performance silicone item, it was installed in April. Can't say it is or isn't collapsing but given that boost generally does seem to come in around 3200rpm I'd say it's probably not collapsing. Car is going on the rollers end of Jan so I'll be able to watch it then.

Hopefully someone responds to my help request for VAGCOM but I only know of one guy around here with it so that's not easy to come by either. I got a bit of Christmas money which I was hoping to spend on a rear ARB but perhaps putting that toward my own VAGCOM setup might be a better investment.

 

[8bit]

OK I might be able to get a throttle body reset and some logging done over the weekend. What blocks are worth logging? I guess we need to see airmass intake, timing retard for all cylinders, N75 duty cycle, spec vs. actual boost, anything else?

 

[8bit]

Update - FIXED - I think.

This afternoon I checked the TIP, upper intercooler hoses, all hoses to/from N75 and N209 and the turbo to charge pipe hose for splits or leaks. Checked the cone filter etc. also. Decided (partly out of desperation) to check the DV again. It was still sticking in the open position and felt a bit stiff pushing the piston inwards.

Took it apart again and put a fairly liberal helping of the grease I had left over from last time in around the O-rings and it seems much better now. I didn't want to put too much grease in last time in case the excess got sucked through the TIP into the turbo inlet, guess I was a bit too sparing with it.

Took the car for a quick run and it seemed much better, sounded better when coming on boost, spooled from low 2000rpm range building to full boost on WOT at about 2800, every time, from closed throttle or part throttle, in all gears.

So I *think* this has sorted it, or at least I know next time to put more grease on the DV. Going to get the car logged and TB reset done again anyway, if for no better reason than peace of mind.

Thanks everyone for your valuable help, very much appreciated.

 

[traumapat]

Yay! if its visibly sticking it must be that. result

 

[8bit]

It was worse than it was before I first serviced it. Back then I tried the push test and maybe one time in every 4 or 5 it stuck open but it didn't seem to have any trouble opening in the first place. When I first pushed it in today it felt like it was stuck shut and every time I released the finger it stayed open.

Will keep a close eye on it and grease it again if this reappears. Cheers again!

 

[robertbadlad]

could be your maf. i kept having a boost leak code due to a dead maf. new maf and problem solved.

did your traction control light on with your dead maf??
last time mine went it bought up that light.

 

[jamie1]

only just noticed this thread and that you got it sorted at the end of december. thats good news anyway to hear its fixed