HELP!! mk1 172 Idle Problem/Manifold probs

[RichMcc]

(Mk1 172 with throttle cable)

I took the top of my inlet manifold off to do some work on it and now that Ive put it back on I have problems.
As soon as I start the engine the revs shoot upto 2000rpm then drop to 1500rpm then if its cold it drops to about 1100rpm.

Then if I tap the accelerator the revs shoot up as expected but it wavers up and down around the 1750rpm and will not go any lower until switched off. Thats even if you lift the accelerator putting no pressure on the throttle cable!

I replaced the gasket between the throttle body and the manifold as well as the one between the two sections of the manifold. I didn't remove the lower half.

I made sure all the breathers were connected back up, sensors etc, everything is exactly how it was before I took it off :S

I might add it idled a little dodgy before some times cutting out if you were reversing into a parking space as the power steering swipes the engines power so I think it was idling too low before but its never been too stable.

It drives but idling at 2000rpm is bad :dead:

Anyone got a clue because Ive been trying all day to sort it without any luck?

 

[Fred@BTM]

(Mk1 172 with throttle cable)

I took the top of my inlet manifold off to do some work on it

ISCV??

what the hell did you do to it??

 

[RichMcc]

ISCV??

what the hell did you do to it??

 

[Fred@BTM]

"my eyes!!!"

did you flat it first??? then bench polished?

 

[cK]

That looks mint, maybe stepper motor if it keeps revving up and down.

 

[RichMcc]

whats a stepper motor? lol

some power tools, LOTS of sand paper, time, some beafy buffering and some broken fingers! (its not 100% finished yet)

 

[hkka]

Are you sure all sensor plugs connected?

 

[RichMcc]

Yep tripple checked everythings plugged in and all the pipes are connected :S

I think its either leaking air some where after the TB or the idle control valve is shot...

 

[ben_p]

same this has happend to me! i took mine off now it idles at 2700rpm, it will be the vdo valve, there 50 from renault

 

[ben_p]

http://www.cliosport.net/forum/showthread.php?t=112554 << mine is stil not fixed, could u do me a guide for that polish?

 

[RichMcc]

Well Ive decided Im going to rip it all off again (luckily I bought 2 sets of gaskets lol), I'll also go nuts with some gasket sealant to eliminate the possibility of an air leak, clean the ICV and if that doesn't work then I'll look into a new valve.
Man the car gods are picking on me! :banghead:



As for a guide I started off with a few different sized flap wheels and a drill then beasted most of the rough crap off (dont take much off at all!), then did the finer bits with a dremel (between the letters etc). Then worked my way from an 80 grit to a 1200 grit paper and made sure the surface was as smooth as possible. Finished off with a buffing wheel and then a ton of autosol and rags.

Beware when using power tools if you make a mistake it takes a long time to put it right, you cant put the metal back on once its gone.
Also where the gaskets go cover the whole area in masking or electrical tape as not to scratch them and to keep the metal dust out, you dont want that in your engine so stop any getting inside!

 

[benji&eka]

check your throttle cable is not kinked and has a nice sweeping curve to it as it comes from the tb. quick check, when its doing its high idle speed thingy lift the thottle pedal by hand and see if it makes a difference

 

[RichMcc]

Yeah done that ben, even if I disconnect the throttle cable it still does the crazy idle shiznits

 

[ben_p]

yer u can hold the t/b closed ant it still revs, its the vdo valve

 

[Andy GDI]

a little wd40 sprayed nr where there may be air leaks will help isolate the problem.... often there is a leak on the seal at the back of the cam cover to the plenum... oval looking rubber seal.... does not always sit right...

 

[RichMcc]

I was thinking to myself earlier the only seal I cant see is the bottom one and 10 to 1 if its leaking it would be that one lol

Cheers for the info guys, I'll clean out the ICV and if that doesn't work I'll take it all off again.

I'll let you know how I get on....

 

[ben_p]

yer ill try that too, although when i put my finger over the bottom of the icv and seal it, the revs do drop

 

[RichMcc]

gauh well i took it all off, sealed it all back up so theres not a chance in hell its leaking. Took off the ICV and sprayed it through with carb cleaner.
tried it again... same thing.
Took the ICV off again and pushed the valve open and cleaned it again.

Tried again and the revs shoot up to 4000rpm so it looks like the valve its toast.... :banghead:

Its not doing a damn thing by the looks of it, aint opening or closing.

So its down to renault tomorrow for an over priced part that they wont have in stock so I'll have to wait EVEN longer

Still it looks pretty tho

 

[Andy GDI]

thats a bugger.... have you tried soaking it in cleaner for a couple of hours....

then giving it some WD etc.... just in case its well caked inside...

might save a few ££

Andy

 

[RichMcc]

Its clean as a whistle mate, tbh it wasn't right before I took it off, idling a bit low and some times cutting out while manovering in car parks etc. So it kinda makes sense that this is whats causing it. Add the latest problems to the list and it all points to the valve.

It seems dead now anyway... ho hum...

Anyone know what cosmetic damage the "intake mod" will do to my manifold? I was going to port match it myself but Im thinking I would see better gains from it getting it done by a pro. Besides I dont want to touch this damn manifold again! :rofl:

close up

 

[Andy GDI]

no cosmetic damage at all..

 

[Gaz_]

thats awsome looking, well done!!!

 

[caymanr26]

fred are you gonna be able to get my fuel rail guard looking like this?

 

[RichMcc]

fred are you gonna be able to get my fuel rail guard looking like this?

Im sure I read some where the manifold can be cut open, ported and welded back up??

the top of my fuel rail guard is done :approve:

Rocker cover next muwahahah

 

[Andy GDI]

Im sure I read some where the manifold can be cut open, ported and welded back up??

the top of my fuel rail guard is done :approve:

Rocker cover next muwahahah

Yes it can, Ben at AWT did this..... to Ross's car.....

its a large process and took ben along time...... the manifold gets some lengthy work inside to reshape the inlet runner opening....

it works as well.... but you will need to pay decent ££ as it tool along time and is heavily labour intesive......

so temp Ben with ££ and he MIGHT to it