Another day, another fault code

[AntStark]

A beautiful day on the South coast today so took the zed for a quick topless blast to blow away the winter cobwebs (mainly mine!)
Anyway, a few yards from home the dreaded engine light reappears…and it’s a new one! P0170 - AB Check Fuel Supply System. What do folks think? …fuel filter? I replaced most of the vacuum hoses last year but maybe I check that again. It seems to run ok

 

[t-tony]

Fuel trim malfunction. I would suggest it’s likely to be an air/vacuum leak.

Tony.

 

[bombur]

I kept getting this code and I put in a new fuel cap seal and this worked for me. Old one had perished.

 

[AntStark]

Thanks both. Fuel trims seem fine..I think that would be different fault code description anyway @t-tony
@bombur was that a dealer part you got ?

 

[bombur]

This is the one I got

Pardon our interruption...

 

[AntStark]

Thanks..the one on my car is flat ..like this. It looks in ok condition but after 20 odd years it’s probably worth trying to find a replacement

 

[t-tony]

Fault code P0170 - Bing

Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you.

www.bing.com

Tony.

 

[AntStark]

Thanks Tony. I know P0170 is usually ‘fuel trim bank #’ related..however this one is quite specific to fuel supply which is why I asked as l’ve not seen it before. Not much comes back on google search either.

 

[Nodzed]

2000 e46 318ci - Fuel Trim Malfunction (Bank 1) p0170

hello, i have a x reg 318 ci and the emissions light has come on, i use a mac tools code reader and it has read the code p0170 Fuel Trim Malfunction (Bank 1) has anybody had this fault or anybody know how to tackle this problem? many thanks stephen

www.bimmerforums.co.uk

Some alternative suggestion on here. Not Z3 but........

 

[AntStark]

Thanks Nodzed..again it’s a weird one as it’s not the fuel trim error I have had before with a 170 code. Interesting it says that it could be the evap valve as I also noticed it was hard to fill up with petrol last time, the petrol pump kept cutting out.

 

[bombur]

Did you resolve this @AntStark ?

 

[AntStark]

@bombur Hello mate.....I sure did! Embarrassingly the issue was hiding in plain sight! Vacuum hose had popped off the bottom of that black and white valve. Literally a 2 second fix and a reset the code. I did buy a new fuel cap as well though as mine was a bit perished.

 

[bombur]

Thats good, sometimes its the obvious! Mine popped up again when I checked this morning. I haven't checked it for a while and had new cat back fitted Friday as had exhaust gas leaking from 1st resonator. So fingers crossed it was from before. Since I changed the fuel cap the code stopped ..so I put it down to that. Maybe a combination of things.

 

[AntStark]

Mine is unbelievably sensitive to any kind of vacuum leak.

 

[t-tony]

They all are.

Tony.

 

[colb]

All of our engines need a fully sealed vaccum system to keep all the sensors happy, if you can't find any air leaks visually then always best to smoke test to find the leak(s). Some leaks are not in the obvious places such as dipstick tube O rings failing and in one case I worked on cracks in the plastic cam cover around No4 plug. Smoke testing found the leaks straight away, so glad I made a smoke machine, made the job a lot easier to resolve. Take a look on youtube for how to make a smoke machine.

 

[bombur]

Like this one? @colb
No more troubles lol View attachment 218109

 

[NZ00Z3]

How to Smoke Test

There are so many requests for solving problems that usually start with "do a smoke test for vacuum leaks" that there's a real need to have a single thread dedicated to smoke testing. Then we can just post the link to this thread when someone needs smoke testing info. Please chime in with your...

www.e46fanatics.com