Exhaust smell, down on power...

[Sirocco20348]

Ok one last boost leak test this morning..

This time with the soapy water spray. I identifed that my injector seals are leaking quite badly. I always thought it was the hiss from the oil fill hole. But soapy water spray does not lie....

Tomorrow morning 9am, injectors are being cleaned and o-rings replaced.

Hopefully t's just the seals and not the injector seats themselves..

[Sirocco20348]

Injectors were in excellent condition, the flow rate was slightly different between all 4

I reinstalled everything and conducted a boost leak test again, and as expected, the injector seals are no longer the problem, the injector seats are leaking air.

Drivability is getting better. I have ordered some billet injector cups from Phenix Engineering and some slightly bigger o-rings they offer. This should nail the leaking injector seat situation.

[Sirocco20348]

I got around to installing the cups. Removal of the old ones was a pain in the ass. The first two cracked when I tried to remove them. I then used a flame to heat up the outside of the manifold, this helped a bit.... They still ended up cracking..

The aluminium threads were messed up a bit as well. Here's hoping the thread sealant does its job.

I will put it back on the car today.

[Sirocco20348]

All installed back in and the car starts which is a bonus. I haven't driven it yet, I'll give it a few more days for the sealant to cure...

[jmcc]

looks alot better, good luck! Aluminium threads are a pain all around this engine it seems, my sump looked like someone had been spinning the bolt with an impact driver or something when I got it out the first time.

[dubster99]

Injectors were in excellent condition, the flow rate was slightly different between all 4

I reinstalled everything and conducted a boost leak test again, and as expected, the injector seals are no longer the problem, the injector seats are leaking air.

Drivability is getting better. I have ordered some billet injector cups from Phenix Engineering and some slightly bigger o-rings they offer. This should nail the leaking injector seat situation.

Do these fit the injectors? I was going to order some but was afraid that my 386cc injectors wouldn't fit because they are larger

[Sirocco20348]

These cups are 100% identical to the plastic ones that are currently in our AGU.

1.8T Injector Cups - Large Port - Phenix Engineering

They are available from many companies, but I bought from Phenix, as they were very responsive on Facebook Messenger with all my questions.

I had a hairy moment yesterday, as the car would not start. For some reason the engine was flooded with petrol, perhaps because I stopped and started it so quickly yesterday.

To solve this, I pulled the fuel pump fuse and keep cranking until it sputtered to life.

I drove around last night very leisurely as I haven't boost leak tested my car since I put it back together.

I'll type up some more findings soon, but the cabin fumes have been greatly reduced.

[Sirocco20348]

Update:

The injector cup replacements have solved the exhaust smell in the cabin.

The performance problem is still there, but I think I am onto something. N75...... This assholish valve.

I replaced the n75 a year ago with a new genuine E valve, so it has not been on my radar.

I am currently running the E valve, but I swapped it out for the F valve I have lying around (I replaced this last year due to suspecting it was faulty)...

The difference was magical. Not 100%, but way more power, boosting 20psi etc. Vagcom confirmed 99.6% duty cycle. It was so strange thou, similar boost achieved but smoother, stronger performance.

But that didn't last long, as expected performance soon became even worse but not too far off what I had previously with the newer E valve (providing about 15psi, but it felt like it was dumping the boost out).

I then unplugged the n75 from the turbo actuator, and I could maintain 22psi no problems.

The ohms test for the n75 is very misleading I find. The valve resistance reading could be in range but clearly faulty.

I'm going to replace the n75 again. $130 from dealer. I bought off eBay last time.

[Sirocco20348]

I just realised I had a thread created for n75 potential problems in 2014, but resolved via boost leak fixes haha.

Diagnosing a malfunctioning N75

I have boost leak (plus smoke tested at mechanic) tested this stupid car until the cows have come home. Surely I have them covered.

[jmcc]

Is it just when it gets up to temperature? I saw something yesterday on the UK mkiv Facebook about overheating the actuator? Seems unlikely, it's built to be connected to the turbo, they had to have engineered it for heat right?