Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: star_whites on 10 June 2007, 21:19:39

Title: Engine stalling when fan swithced on??
Post by: star_whites on 10 June 2007, 21:19:39
Ok Ive had all the electrical systems sorted and stopped the car idling erratically due to cleaning the throttle housing and breathers and hopefully will pass the MOT tomorrow without any hitches(fingers crossed) however:

On running the car on the side of the house making sure everything is ok, I swithced on the fan due to removing pollen filter to make sure all ok and the engine stalled. Started engine and tried again to find that the revs drop to 2500 when the fan on and the engine struggles. Any suggestions as Ive set the throttle up so that it revs at 6500 but my question would be that I did not remove the EGR and clean that seperatly whilst cleaning the throttle housing, should I have??

Or is there another issue, ps no waring codes up before anyone asks lol
Title: Re: Engine stalling when fan swithced on??
Post by: Kevin Wood on 10 June 2007, 21:35:56
Do you mean 250 and 650 rpm?

6500 rpm is a tad high as an idle speed  :o  ;)

Anyway, two points to note. The throttle stop should not be adjusted to set the idle speed on these engines. Idle speed is regulated by the ECU using the idle air valve. The throttle stop is adjusted so the throttle plate closes fully but does not jam in its' bore when the pedal is released and the ECU should control the idle.

Secondly, if the idle speed is unstable or responds to engine load (electrical accessories present extra load on the engine via the alternator) it points to the idle air valve being faulty or clogged up.

A faulty idle air valve that has been overlooked may cause the throttle stop to have been adjusted to stop the engine stalling, but this will never give satisfactory idling under all conditions.

I'd have a look at the idle air valve and, in the first instance, give it a clean. Have a look in the HOWTOs.

Cheers,

Kevin
Title: Re: Engine stalling when fan swithced on??
Post by: ians on 10 June 2007, 22:12:48
Did you mean ICV rather than EGR?  Well worth giving that a clean out as Kevin suggests.

I think it would also be worthwhile checking battery volts at idle with and without load (aircon etc) - it maybe your battery is on its last legs or you have a dodgy alternator.
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 10 June 2007, 22:25:56
Yes I meant 250 and 650  ::)

I had altered the Throttle Stop, however I will reset this back up tom night. I take it the Idle air valve is the one situated to the right of the rocker cover next to the power steering resevoir.

Ref the battery, I did not have this fault prior to the head gasket going and the engine starts first time every time even when left for long periods. It also has a self monitoring device installed to the battery that tells you if its starting to fail, this is still green so thats fine. Will get alternator checked though just to make sure.
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 10 June 2007, 22:41:31
Ive had a look in the HOWTOs, however I cant see anything relating to the cleaning of a idle control valve.

Either Im blind or its not therre.

Any advice on how this is removed and cleaned??????  :-/
Title: Re: Engine stalling when fan swithced on??
Post by: ians on 10 June 2007, 22:48:39
The ICV is bolted to the front of the throttle housing (we are talking about a 2.0 aren't we?) on the drivers side (if it was 2.5/3.0 - you would be correct - it is adjacent to the power steering reservoir).
Its a cylindrical thing - looks like this....
http://cgi.ebay.co.uk/Vauxhall-Idle-Air-Control-Valve-Astra-Vectra-Omega-B_W0QQitemZ160113916571QQihZ006QQcategoryZ10404QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 10 June 2007, 23:57:46
Ahhhh yes it a 2.0 1998 Auto

Yes it is that and I did spray some carb cleaner into it when I had the throttle housing off however I did not strip and clean it as a) did not know what needed cleaning in it and b) I did not have a gasket!!

Has anyone got any instructions on how I should strip this and what I should be cleaning??
Title: Re: Engine stalling when fan swithced on??
Post by: gizza on 11 June 2007, 08:49:10
Quote
Ahhhh yes it a 2.0 1998 Auto

Yes it is that and I did spray some carb cleaner into it when I had the throttle housing off however I did not strip and clean it as a) did not know what needed cleaning in it and b) I did not have a gasket!!

Has anyone got any instructions on how I should strip this and what I should be cleaning??
remove the icv from the throttle body 2 x 5mm allen bolts 1 top and 1 bottom and disconect the black wiring plug from the end now you will notice that it has 2 parts and these need splitting by removing the 2 cross head screws be carefull there is a rubber o ring between the 2 parts, now spray some carb cleaner into the part with the electrical connection on it and give it a good shake you should hear a clicking noise this is the servo keep spraying and shakinfg till the fluid comming out is clean now put this to the side to dry out, and do the same to the other part of the icv try and remove as much of the black crap off it i find a toothbrush works well just not the wifes, now the fist part is dry get some 3 in 1 oil and squirt it inside and give it a shake and let the excess oil run out, now reasemble the 2 parts of the icv remembering the rubber o ring and replace on to the throttle body replacing the gasket if it looks knackered, a tip if your breathers are blocked the small pipe that runs from the cam box cover to the throttle body and the connection at both ends is blocked then the icv will foul up again soon as the small pipe is for idling and if its blocked then all the gases from the cam box go through the large pipe which is before the icv causing it to clog up, this is a very easy job to do and if the icv is knackered dont bother with vauxhall main stealers either autovaux or ebay,lo m8 got my ps3
 main dealers charge £120  
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 11 June 2007, 18:48:42
Ok, update!

Car passed MOT with flying colours except for close on emmisions but tester stated that if head had just been changed then it needs time to set itself up.

However, have been informed that she stalled just about everytime you slowed to a halt. Going to take egr off in a minute and give that a really good clean, however just wondering if anyone else had any ideas.
Title: Re: Engine stalling when fan swithced on??
Post by: Kevin Wood on 11 June 2007, 19:01:43
Quote
However, have been informed that she stalled just about everytime you slowed to a halt. Going to take egr off in a minute and give that a really good clean, however just wondering if anyone else had any ideas.

I'd say check the EGR, the ICV and also have a good look for leaks around the induction system, breather and vacuum hoses and also the exhaust system.

My money's on the ICV. It might be worth lubricating this with some WD40 or similar. If it's just been cleaned out with carb cleaner and left dry, maybe it's jammed closed?

Kevin
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 12 June 2007, 07:57:11
Ok heres an update.

I removed the ICV (Not the EGR) and gave it a really good clean and oiled as suggested. Could here movement when slightly shaken. Had to refit with original gasket due to my daughter (10 Months) tearing and squashing the brand new one I just bought. Teach me for leaving it on the sofa.

All hoses had been previously cleaned at the weekend along with the throttle housing. Started her up and she sounds great. Swithced on fan, aircon, heaters, radio, lights and anything else I could find to drain the power yet she did not stall. Took her out and had a drive no stalling, come to my first island and stalls ahhhhhhhhhhhhhhh

One thing I have noticed though is the serious drop in power since all the work was done. Also noticed that the kickdown is not as responsive???? andy ideas????

Going to order another ICV gasket today so will change that shortly.

Other thing is which is EGR valve???
Title: Re: Engine stalling when fan swithced on??
Post by: Martin_1962 on 12 June 2007, 09:54:56
Did you do the pipe into the inlet manifold?
Title: Re: Engine stalling when fan swithced on??
Post by: ians on 12 June 2007, 12:25:46
I'm not sure there is an EGR valve on 2.0L

Did you clean the small bore breather pipe and the metal port just below the throttle housing?  The metal port was likely solid with baked gunk.  
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 12 June 2007, 18:12:10
Yes  :) , cleaned all pipes, hoses and ports.
Title: Re: Engine stalling when fan swithced on??
Post by: Martin_1962 on 12 June 2007, 21:17:31
Give it a few days to relearn the cleaned breathers
Title: Re: Engine stalling when fan swithced on??
Post by: star_whites on 13 June 2007, 07:54:52
Ok. thanks. Will see how she goes. Did go out in her last night and she didnt stall, but am finding that there is a funny squeak from around the cam/auxillary belt area and sometimes sonds tappaty.

Going to change the oil incase the mechanic didnt and see what difference that makes  ::)