205 1.9 Gti engine problem

205 1.9 Gti engine problem

Author
Discussion

Morty

Original Poster:

18 posts

218 months

Monday 11th September 2006
quotequote all
Hi...

Please can anyone shed any light on why the breather pipe between the inlet manifold and the air flow meter has been blocked off on my Pug?
The air flow meter might be a little tired ( Ok, broken perhaps.) The mixture is definitely too rich (smells lovely!) When I try and adjust the mixture down, nothing much seems to happen.(Although it does seem to adjust up.!).The engine idles at between 1500 and 2000 rpm once it is warm. And if I adjust that down it tends to stall a lot when the engine is cold.
I know that blocking the pipe was a bodge job for something but what problem is it a bodge for...? Surely if it was just the air flow meter that was the problem, then it should have just been replaced. ( During big rebuild project last year.) Any insight would be appreciated...

sorrento205

2,875 posts

243 months

Monday 11th September 2006
quotequote all
there are two hoses which link onto the big pipe between the throttle body and afm, one to the sad and one to the top of the oil filler cap. sounds like it could be the pipe from the SAD (supplementary air device).

Mikey G

4,784 posts

247 months

Tuesday 12th September 2006
quotequote all
It has been known for people to block off the SAD unit due to it malfunctioning, this is only used for cold starting.
I would make sure both ends are blocked properly if this is the case. I have seen the manifold end (below the plenum chamber) break and cause rough running as it sucks in extra air past the AFM and throttle butterfly.

Worth checking your throttle position switch if you are suffering idle problems, you should just hear the click when you gently open the throttle off its stop.
Check to see if someone has opened the top off the AFM, telltale signs are some new silicone to stick it back on. If so remove it again and check to see if its been tampered with, normally people will mark the spring tensioner before making adjustments but some dont, if its marked return it back, if not find another AFM and see if the car runs better.

Rob_the_Sparky

1,000 posts

245 months

Tuesday 12th September 2006
quotequote all
Trouble is that if someone blocks of the SAD (what a bodge!) then you either will have no idle when cold or very high idle when hot...

sorrento205

2,875 posts

243 months

Tuesday 12th September 2006
quotequote all
supplementary air device explained: www.205gtidrivers.com/articles/e3-sad.html

Mikey G

4,784 posts

247 months

Tuesday 12th September 2006
quotequote all
Rob_the_Sparky said:
Trouble is that if someone blocks of the SAD (what a bodge!) then you either will have no idle when cold or very high idle when hot...


A lot of people in rallying totaly remove it from the system as its not really needed, nothing a little kick on the throttle can sort out to keep it going when cold

With regards to idle adjustment, the number of people i have seen trying to alter the throttle stop instead of the air bypass screw is shocking! under no circumstances should the stop be adjusted unless there is a problem with it and the position switch it also affects.

Rob_the_Sparky

1,000 posts

245 months

Tuesday 12th September 2006
quotequote all
But racing/rallying is not a road car. Driving with no tick-over when cold is a pain in the bum in morning traffic, not a problem you have when racing...

Morty

Original Poster:

18 posts

218 months

Tuesday 12th September 2006
quotequote all
Woah.! Wow. Amazing amount of response, thanks so much everyone..! I'd better get reading up on all this then. Bit more complicated than I'd hoped...! I certainly don't know enough to fix this over night.
Rob the Sparky, nails,heads and hitting comes to mind..!
Mikey G, regarding the idle adjustment, I'm guessing I got the right thing (otherwise the mechanic who showed me would prove to be a real 'spanner') I'm sorry to say that the bit you wrote about AFM went just a tad over my head (I confess that I am but a girl of little mechanical comprehension) But thanks for the tips which I WILL get to grips with, given time!

Morty

Original Poster:

18 posts

218 months

Tuesday 12th September 2006
quotequote all
Sorrento205, I just checked out that webpage you mentioned...! VERY useful! Thanks! ( Does anyone else find Haynes a bit misleading at times..??)

simes205

4,660 posts

235 months

Tuesday 12th September 2006
quotequote all
Morty said:
Sorrento205, I just checked out that webpage you mentioned...! VERY useful! Thanks! ( Does anyone else find Haynes a bit misleading at times..??)


The Haynes (book of lies) is quite bad. The earlier edition for the 205 is best
Join the forum it will help with everything.
I often inherit symptoms I read about on there!

Edited by simes205 on Tuesday 12th September 21:48

Morty

Original Poster:

18 posts

218 months

Wednesday 13th September 2006
quotequote all
Mikey G said:
It has been known for people to block off the SAD unit due to it malfunctioning, this is only used for cold starting.
I would make sure both ends are blocked properly if this is the case. I have seen the manifold end (below the plenum chamber) break and cause rough running as it sucks in extra air past the AFM and throttle butterfly.

Worth checking your throttle position switch if you are suffering idle problems, you should just hear the click when you gently open the throttle off its stop.
Check to see if someone has opened the top off the AFM, telltale signs are some new silicone to stick it back on. If so remove it again and check to see if its been tampered with, normally people will mark the spring tensioner before making adjustments but some dont, if its marked return it back, if not find another AFM and see if the car runs better.

Do you think that replacing the AFM would help, or is it more a matter of adjusting bits and pieces to get it running more smoothly...? There's no sign of tampering as such, the whole engine was rebuilt last year, I didn't really even look under the bonnet before that was done.. Although I did ask for as many of the original parts to remain (if they were sound) when it all went back in.. I do know that the electrics are in a bit of a state, I'm putting in a new wiring loom in a week or two..

simes205

4,660 posts

235 months

Wednesday 13th September 2006
quotequote all
Check out the forum, there is a huge guide on how to re-track the AFM on the jetronic system.

Morty

Original Poster:

18 posts

218 months

Thursday 14th September 2006
quotequote all
Erm. Thanks for the tip, but I'm new to this whole forum business, where do I find that bit please...?

sorrento205

2,875 posts

243 months

Thursday 14th September 2006
quotequote all
http://forum.205gtidrivers.com/

im not totally ofay with the forum procedure, but i believe you have to go into this section http://forum.205gtidrivers.com/index. teh new users startup and make a post stating you promise to abide by the rules etc etc

apart from that the forum is really good and i'd recommend it to anyone with a 205/309/405 for all the help and advice available there

Morty

Original Poster:

18 posts

218 months

Thursday 14th September 2006
quotequote all
Thanks...! I need all the help I can get...!