BMW 1 Series: Cold Start Issues, Power Loss, Misfire?

Hello,
'I'm having a problem with my Golf Variant (engine code 1Z, manufactured in 1995). Sometimes, when the engine is cold, it runs really poorly. After starting, everything seems normal at first, but after about 1-2 kilometers, it suddenly loses power and starts to misfire badly. If I continue driving, the problem usually goes away after about 30 seconds. Does anyone have any ideas?'

Sure.

hanging N108.

This is the injection start control valve.

It is located in the fuel injection pump and pulse-width modulates the internal pressure of the pump to actuate the injection control valve.

However, this should also be logged as an error in the engine control unit (ECU).

Here are a lot of pictures (assuming the server isn't having any problems with its Wi-Fi).

http://www.luxus-wg.de/~martin/auto_bilder/SeatArosa/

m;

Thank you.
I'll check that out.

Well,
No errors found in the control unit.
It's really hard to reach that valve.
Can I simply remove it without any concerns? Or are there any potential surprises?

No.

Don't just take it apart, because you probably won't see much.

Please check the fuel injection timing (target vs. actual) using VAGCOM, especially if the car exhibits this "episode" in the morning.

It's possible that a nozzle could become clogged (can nozzle holes also get clogged???), and if it's not the nozzle for cylinder 3, you probably won't see anything electronically.

A "basic setting" in Block 004 should also provide more information about whether the ESP can follow the target values of the engine control unit.

m;

Hm,
Not that easy at all.

According to the diagram, the initial support value is almost at its optimal level.
So far, I haven't been able to test his seizures because the seizures are too short or the eBay device is too slow.

golfschrauber1981 wrote:

After approximately 1-2 kilometers of driving, the vehicle suddenly lost power

.

Hello,

I'm also experiencing this problem with my Passat: a few minutes after a cold start, the engine suddenly loses power, but without any misfiring. If I manage to exceed 2000 rpm (which I don't like to do), everything goes back to normal.

It is interesting that there is a clear dependence on the climate. It only occurs when it is cool and humid outside .

Unfortunately, I haven't been motivated enough to investigate the cause yet, because it only happens in the winter. However, I suspect there might be a problem with the turbocharger's boost pressure system: specifically, a stuck-open wastegate, possibly due to a faulty solenoid valve or a problem with the wastegate itself.

An LDA (Local Distribution Adapter) is slowly becoming a necessity .

Hey, exactly!

A "frozen" N75 (boost pressure control valve).

This explains the loss of performance, especially in "bad" weather - but not the rattling noise.

My N75 also sounded very different in the cold. When I started it, it would slowly sputter to life, as if it needed to warm up.

Because I was annoyed by the sound of the stapler, I threw it away.

Since then, nothing has gone wrong, and there have been no problems (although there were some before).

m;

It sounds almost like what I'm experiencing, but the knocking sound usually suggests a fuel problem.
I suspect my fuel pump might be malfunctioning (specifically, the fuel injector). The strange thing is that it only happens sometimes and for a very short period, and only when the engine is cold. Otherwise, it runs really well.

I guess I'll just have to live with it for now, but I'm planning to get a completely rebuilt engine installed this summer.

I might still replace the N75 just for fun (I have one lying around), you never know with a TDI .


Nevertheless, thank you!

golfschrauber1981 wrote:

I might still swap the N75 just for fun (I have a spare one) because you never know with a TDI

.

Okay, please let me know, and then I will also go outside ...

Okay, I replaced the valve. It's from a Passat (the retaining rubber doesn't fit, but it's fine).

Now it's time to observe.

I'll get back to you in a few days.

Well,
Too bad, but that's definitely not it. I'm leaning more towards a hanging N108 error.

Unfortunately, my laptop has given up the ghost, goodbye VAG-Com .

I'll just swap it with one from my reserve ESP.

Hello,
This afternoon, my car had another episode, but it lasted longer and was more severe than usual.
Okay, stopped. Hood up.
Light taps on the ESP, no reaction. I thought: 'Great, now you're stuck out here in the middle of nowhere.'

Then, just for fun, I sprayed a little bit out of each nozzle, and lo and behold: the NBF nozzle is defective.
(After the knock, the engine runs normally.)

Okay, so my new problem is that I have a brand new NBF injector, but unfortunately it's from an AFN engine.

Does anyone happen to have three standard AFN injectors (part number: 028130201T) that they're looking to sell?

If so, please send an email to Hinrich_berndt(AT)web.de.

golfschrauber1981 wrote:

NBF nozzle defective

Hello,

That sounds interesting. I've never heard of those symptoms before - I've learned something new.

I will (hopefully) soon investigate my lack of power after a cold start (while it's still cold outside). However, I am 99% certain that the problem lies in the intercooler system.

Hi Christian,

Is your N75 (boost pressure control valve) guaranteed to be working correctly?

Mine sounded noticeably different when it was cold compared to when it was warm, but it still worked.

30 euros and it's brand new.

m;

dieselmartin wrote:

Is your N75 (boost pressure control valve) guaranteed to be working correctly?

Hi Martin,

I also think the N75 valve is not working correctly. This issue only started happening after I replaced the valve. Unfortunately, I no longer have the receipt (as usual), otherwise I would have already exchanged it at the dealership. I'm wondering if it's really worth investing in a new valve... I will definitely report back on what happens.