Mi16 Idle "chug"

[jackherer 543]

Which bit of the throttle body gets worn then? Just thinking maybe there's some way to fix it.

 

Primarily the linkage between the two butterflies and to a lesser degree the spindles the butterflies rotate on.

[kate205gti 4]

ooh my 1.1 on a single carb does this too will check for air leaks!

[KRISKARRERA 2 1 Cars]

Primarily the linkage between the two butterflies and to a lesser degree the spindles the butterflies rotate on.

Hmm, then maybe something could be fabricated to fix it.

[timmsy19 3]

if you do Kris let us know as you might have a group buy on your hands by the way this thread is shaping up

[jackherer 543]

Hmm, then maybe something could be fabricated to fix it.

 

Having had throttles jam open I'm not keen on repairing old ones, fitting newer ones and adapting the throttle switch as needed strikes me as a much better idea.

[KRISKARRERA 2 1 Cars]

Is it because the linkage gets worn and the lower butterfly flaps about slightly? The spring is really weak on that lower one.

[GLPoomobile 958]

Considering that the throttle body is actually about as mechanically simple as a metal retard, surely a lot of decent engineering workshops would be able to refurbish or reproduce the spindles and linkage. May not be cheap, but it's another option. And as far as not being safe goes, a decent workshop would probably be able to able to get the tolerances much better as they are building it by hand.

[KRISKARRERA 2 1 Cars]

Yeah there's gotta be some way to sort it.

I wonder if Pug or Citroen still sell these throttlebodies. Unlikely. If they do it'll be about £200+ I imagine.

Actually, why did they decide on a twin butterflies!

[jackherer 543]

Its listed as NFP but you wouldn't buy one even if they did still have any.

 

0000163541 AIR INTAKE CASE 294.20 GBP 345.69 GBP 345.69 GBP

 

(odd name but I am pretty sure that is the right part)

[timmsy19 3]

so if its expensive to replace. what other tb's fit

 

i know its been coverd i just cant find it at the mo

[jackherer 543]

so if its expensive to replace. what other tb's fit

 

i know its been coverd i just cant find it at the mo

 

VAG A4/A6/Golf VR6 2.8 V6 according to http://www.205gtidrivers.com/articles.php?data=e2-vagtb although I am sure others fit too, namely the Golf Mk2 16v IIRC.

[mr_exe 1]

My idle is VERY steady on the mi16 but it still "chuggs" a bit, especially noticeable if you listen to the exhaust!!

 

 

You have just described my car exactly. Looks like the VAG throttle body project is on the cards for winter.

[timmsy19 3]

well time for an update on this one. got my VAG tb going on today so hopefully should stop the chug and most of the kangeroo effect.

 

although i have a blowing exhaust mani so might not make alot of difference

[KRISKARRERA 2 1 Cars]

Any news? Excited to find out if it's helped at all.

[timmsy19 3]

well fitted it today.

 

after 6 hours of f'in and blinding it now doesnt seem to chug at all although a slight chug but thats because i still have a blowing exhaust mani

 

only downside is that it feels like there is ALOT less low down power. not sure if its the tps not set up correctly, the throttle cable on on right or the fact that the humpty that was helping me decided to put a coolant hose on the TB instead of a breather hose. coolant everywhere and ALOT of white smoke

 

feels alot less urgent in all gears at all revs. not sure if thats because of the smaller butterfly and 1 larger one or what.

Edited November 8, 2008 by timmsy19

[KRISKARRERA 2 1 Cars]

Strange. I thought the combined area of both throttle plates was at least as big as the original Mi throttlebody. But still, if the chuggin' has lessened that's a good result and confirms what Kieron says.

[timmsy19 3]

Strange. I thought the combined area of both throttle plates was at least as big as the original Mi throttlebody. But still, if the chuggin' has lessened that's a good result and confirms what Kieron says.

 

im not 100% certain but i dont think the VAG tb has anything to do with ym loss of power

 

im thinking it might have something to do with one of the injector caps or possibly the fact that a small amount of coolant accidently got into the engine bay.

 

the car seems to rev fine but when under load (normal driving) it feels very under powered. its got no surge or urgency

 

anyone have any sugestions?

[jackherer 543]

If it inhaled water all sorts of nasty things can happen including bent rods

 

I'd compression test it before going any further.

[timmsy19 3]

If it inhaled water all sorts of nasty things can happen including bent rods

 

I'd compression test it before going any further.

 

 

good idea.

 

if its lost compression i take it thats a bad thing? but would that mean?

[jackherer 543]

good idea.

 

if its lost compression i take it thats a bad thing? but would that mean?

 

Water is not compressible like air so if some gets past the inlet valve into the combustion chamber as the piston comes up the water has nowhere to go so the rod connecting the piston to the crank can bend or other nasty things can happen.

 

Get a compression tester (£15 ish) or take it to a garage and get them to test it, you may well find its OK, I don't want to alarm you, but its worth checking if you think its sucked some water in the inlet or you could be chasing the problem forever without fixing it.

[timmsy19 3]

right i'll get that checked straight away then

[mr_exe 1]

Fingers crossed that you have not done any serious damage. I'm pleased to hear that its stopped 'chugging' at idle, thought the lack of low down urge is a bit concerning.

[timmsy19 3]

Right bit of an update

 

Got my injectors through the post so fitted those yesterday.

 

Well that did the job of the misfire and got some power back. At this point i'd like to say i really like having the audi Tb now as its not to revvy when at so speeds but put your foot down and its still got life in it.

 

Also fitted my uncracked exhaust manifold. but before i did i decided to port it a little bit as it looked quite cloged up with welds in the oulet holes

 

Anyhow it now doesnt chug as much as it it before, no more kangerooing and best of all no dead engine.

 

Only thing to sort now is a small air leak where the audi Tb meets the inlet pipe as its not quite the right shape. Anyone know if the audi one will do the job and have the same breather hose thing?

[mr_exe 1]

I'm pleased that you have managed to sort it all out, especially after the water episode.

 

I've acquired a VAG throttle body from an Audi 100 so any hints/tips/pictures would be most welcome

[C_W 3 1 Cars]

You get less power on the first 1/3 of throttle with the Audi throttle body as you're only opening a very small throttle (the Mi16 body opens both *almost* simultaneously but the Audi is a lot more staged), it should suddenly come on though as you got from half way openings as the larger one opens more quickly. The non-linear throttle openings is one of the detractions from the Audi throttle and probably makes a big V6 smoother to drive but makes a small 4 pot feel less responsive.