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        General >> Problems >> bad idle and the MAF
        
(Message started by: Mike_Floutier on Nov 5^th, 2007, 8:56pm)

Title: bad idle and the MAF
Post by Mike_Floutier on Nov 5^th, 2007, 8:56pm

Hi,

I'm just trying to sort out my poor idling and have noticed that there is no change when I disconnect the MAF with the engine idling

Is this normal or should I expect a change when disconnecting the MAF during idle?

Thanks

Mike

Title: Re: bad idle and the MAF
Post by jonnycab on Nov 6^th, 2007, 11:44am

I tried this once & also there was no difference to the idle.

The way I understand it, is without the MAF connected it will still idle because the other engine sensors will still provide enough information to the PCM for it to idle okay :)

Have you tried cleaning the IACV with some carb cleaner & then applying a little lubricant to the shaft ?......although, this may not make any difference if the fault lies with the solenoid part of it :)

Title: Re: bad idle and the MAF
Post by peteHull on Nov 6^th, 2007, 12:14pm

I once drove to work after cleaning the maf, the car became so irratic and jumpy I thought I'd damaged it during the cleaning operation. :-/ After work I gingerly drove it home with the intention of changing it for my spare, I lifted the bonnet and low and behold, when I came to disconnect the maf I found I'd forgot to reconnect the multiplug..... ??? I reconnected it and started it up.... :o you guessed it, after a few seconds it ran as smooth as silk again and has ever since, I can only assume the ecu needs to learn the settings.....

hth
pete

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 6^th, 2007, 2:55pm

Ok, so do I understand this correctly, in theory it shouldn't make a difference but in practice it can?

Would somebody mind disconnecting their MAF while their engine is idling to see if it does become lumpy.

That would really helpful cos my car is pretty old and I dont want to fork out for another MAF if it's not going to do the trick

Thanks

Mike

Title: Re: bad idle and the MAF
Post by Tompion on Nov 6^th, 2007, 3:23pm

My 2.3 usually hesitates very slightly when I disconnect the MAF (hardly noticeable).
I just tried it with a cold engine & it stopped dead about a second after disconnecting the MAF, but I suspect it coincided with the aircon cutting in. After the engine had been running a couple of minutes, tried again a few times & just a barely noticeable hesitation.

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 6^th, 2007, 5:48pm

Thanks for that Tompion.

Jonnycab, would you mind telling me a bit more about cleaning the IACV - eg where is it, and do I need to remove it to clan it etc - as I've no idea and I couldn't find anything about it on the site.

Thanks

Mike

PS I should also mention that I have a couple of other problems that started about the sametime as this idling problem and I was wondering if they are related or can help with diagnosis:

1. When starting the engine, the trip milometer occaisionally resets to zero and the mpg figures etc all reset to lts/100km. - This is not the same as the "low battery" syndrome where the needles all whizz round btw. and,

2. The autobox, when thoroughly warm, can only hold overdrive with the very lightest throttle - ie downhill or slowing down slightly - any more and it goes into fourth

Title: Re: bad idle and the MAF
Post by Simmo on Nov 6^th, 2007, 7:11pm

The detail is HERE (http://www.fordscorpio.co.uk/iacvdata.htm). There are two styles as you will see from the diagram. It sits adjacent to the throttle intake and ,yes, it does have to be removed in order to clean it. This is done by 'dosing' it with carb cleaner and then lubricating the moveable 'shaft' with 3 in 1 oil. You will need to replace the gasket to obtain an airtight seal on replacement. To be fair sometimes it works and sometimes it doesn't. Will try and find a photo on the site. Try reading THIS (http://www.fordscorpio.co.uk/manual/engineman/dohc16v/16vIACV.pdf)

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 8^th, 2007, 3:17pm

Thanks Simmo,

I squirted about half a can of car cleaner into it and it was still coming out dark so it was very dirty.

I then lubricated the piston etc as per instructions and reassembled.

It seems to be idling a lot better. It's much steadier now at around 1,000 rpm whereas before it was hunting between 500 & 800rpm.

Will see how it settles down. The main thing is that the difference is so obvious that it must be the cause - always a relief to nail down a cause.

Thanks again.

Mike

Title: Re: bad idle and the MAF
Post by Simmo on Nov 8^th, 2007, 3:37pm

Glad to have helped Mike. Sometimes it is a cure if not it's a replacement,preferably new, FordParts are the best and cheapest. I have the Finis Nos for both types, the 2.3 is different from my 2ltr so give me a shout if you need to go that route. Cheers MIke ;)

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 9^th, 2007, 9:19am

Thanks Simmo,

Yes, after a long trip yesterday it's back to hunting again. I've put in a request to FordPartsUK as fiddling with it certainly made a difference, if only temporary so it looks like it's the culprit.

Will post results in due course.

Mike

Title: Re: bad idle and the MAF
Post by Simmo on Nov 9^th, 2007, 2:16pm

Mike, the part is known as Valve Assembly-Air by-pass and the 2.3 is Finis 1058383 and the gasket 7090339. The total with postage was about £81. :)

Title: Re: bad idle and the MAF +/or IACV
Post by Mike_Floutier on Nov 15^th, 2007, 3:24pm

Just another query about the IACV.

When cleaning it again today I noticed that the spring that is connected to the piston was not connected at the other end (ie to the valve body).

Do you know if this is correct or has it come loose? I guess that would maybe explain the problem.

Thanks

Mike

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 16^th, 2007, 1:27pm

Following on from that, I just found this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260102633824&fromMakeTrack=true#ebayphotohosting on e-bay.

It says it's suitable for Transits and Galaxys but the picture looks exactly like mine. Do you think it could be ok?

Thanks

Mike

Title: Re: bad idle and the MAF
Post by Tompion on Nov 17^th, 2007, 11:36pm

It looks like that uses the oval plug,
they also have this:
http://cgi.ebay.co.uk/AIR-BY-PASS-VALVE-GENUINE-FORD-FIESTA-ESCORT-MONDEO-KA_W0QQitemZ260174084193QQihZ016QQcategoryZ21654QQtcZphotoQQcmdZViewItem

There are others doing them on Ebay showing the 2 types of socket, but when I asked they said not for the 2.3 Scorp.
I suspect it's because the socket comes out at a differant angle/direction compared to the 2.0 & probably fouls the manifold.

Title: Re: bad idle and the MAF
Post by jonnycab on Nov 18^th, 2007, 12:54am

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260102633824&am p;fromMakeTrack=true#ebayphotohosting on e-bay.

I E-mailed this company a few months back, to enquire whether it fitted the 2.3. They replied with a no & said they could do the 2.3 one for about £85.....so same price as FMD :)

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 18^th, 2007, 5:04pm

Hmmm, yes, I see what you mean. Can't look at my plug at the moment due to foul weather - anyway I ordered it yesterday so I'll have to wait and see.

I did speak to an FMD and he confirmed that the Finis number was the same for the 2.3 Scorpio as well as the Galaxy so hopefully it'll be ok.

Will let you know as it would be a useful source.

Mike

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 24^th, 2007, 12:50pm

on 11/09/07 at 14:16:20, Simmo wrote:

Mike, the part is known as Valve Assembly-Air by-pass and the 2.3 is Finis 1058383 and the gasket 7090339. The total with postage was about £81. :)

Simmo, you don't know the part no. (95GB.....) do you?

I've found a breaker who has one but he wants to know the part no. rather than the finis.

Thanks

Mike

Title: Re: bad idle and the MAF
Post by scorpio_man on Nov 24^th, 2007, 1:29pm

hi there

i've got it coming up as 1041963/ 96xf9f715ba.

hth

Title: Re: bad idle and the MAF
Post by Mike_Floutier on Nov 24^th, 2007, 7:53pm

Thanks mate, that's the one. I was expecting a 95bg... no. but that agrees with what's on the side of the unit.

Thanks again

Mike