It is currently Fri Aug 17, 2018 4:19 am

All times are UTC [ DST ]




Post new topic Reply to topic  [ 4 posts ] 
Author Message
Commiestar99
PostPosted: Sun Jul 22, 2018 12:41 pm 
Offline

Joined: Wed Aug 23, 2017 11:54 am
Posts: 12
Location: SE London
Reputation: 0

Good afternoon to you all, I have a 323F/P 2003 GSI 1.6 with the ZM engine. Bought the car with 25000 miles (unbelievable I know) on the clock last year. It has a slowish return to idle when driving and changing up or down the box, is this peculiar to the 323F or should I investigate more. No fault codes showing up via OBD and no inlet leaks on visual and audible inspection with engine running at various rev's. Considering the mileage and service history (main dealer since new, up until a few years ago) I am at a loss. Is this normal? Does this particular engine just a have a slow return down the rev range? Put a cold air induction filter set up on it, runs and breathes a lot better, but still the same.

Any advice or info warmly appreciated, gonna change the oil this afternoon. Castrol edge 5-40W and a jap spec oil filter. Will a bigish trolley jack go under the front bumper lower lip to jack up on front crossmember to put axle stands underneath? Or can I get the car up on ramps with out scraping or destroying the bottom of the front bumper? That is my paradox for today.


Top
 Profile  
 
pitrack_1
PostPosted: Sun Jul 22, 2018 2:44 pm 
Offline

Joined: Wed Jun 24, 2015 5:55 am
Posts: 505
Location: ACT, Australia
Reputation: 3

I'm assuming you have a mechanical throttle linkage here.

Most of these cars (incl mine- but it's a 1.8 BA) have a delayed return to idle as part of the emissions control.. It controls the closure speed of the throttle body- this might be direct through (say) a dash pot, or perhaps indirect, by substituting some airflow through a bypass such as idle air control. This reduces a suddenly rich mixture when the throttle snaps shut but injection continues for an instant. If the airflow 'ramps down' then the fuel flow can ramp down accordingly maintaining the appropriate mixture ratio to reduce emissions. This may also link in with other systems such as air injection and EGR.

Alternately, if the fuel is cut the instant the throttle is shut there's a small period that there is a lean mixture leading to NOx.

Apparently there can also be oil aspiration in the crankcase upon a sharply closed throttle that can lead to emissions issues.

Other possibilities include a possible air leak or sticking throttle mechanism causing extra air to be allowed in, faulty components or even mismatched ECU/components.

Patrick


Top
 Profile  
 
Commiestar99
PostPosted: Mon Jul 23, 2018 11:22 am 
Offline

Joined: Wed Aug 23, 2017 11:54 am
Posts: 12
Location: SE London
Reputation: 0

Thank you Patrick for your reply, yes the car does have a mechanical throttle linkage ( cable throttle control) I am going to have a closer inspection of the throttle body, but reluctant to remove it as you have to drain the cooling system. I will also check various voltages and resistance of associated parts according to the workshop manual. I will let you know my findings.

Mark.


Top
 Profile  
 
jinglebells
PostPosted: Tue Jul 24, 2018 8:45 pm 
Offline

Joined: Fri Aug 12, 2011 10:19 pm
Posts: 363
Reputation: 2

Commiestar99 wrote:
Any advice or info warmly appreciated, gonna change the oil this afternoon. Castrol edge 5-40W and a jap spec oil filter. Will a bigish trolley jack go under the front bumper lower lip to jack up on front crossmember to put axle stands underneath? Or can I get the car up on ramps with out scraping or destroying the bottom of the front bumper? That is my paradox for today.


I find the trolley jack just goes under the bumper lip, then I add a rubber pad on top. Then jack up to the high point and the axle stands just go under.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

Protected by Anti-Spam ACP Powered by phpBB® Forum Software © phpBB Group
Karma functions powered by Karma MOD © 2007, 2009 m157y