Rough idling Granada

Honest John Back Room » Technical matters
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Tue 15 Apr 2003 22:37
Rough idling Granada - Rob the Bus
Not being the most technically minded chappie, I'd be exceptionally grateful (I may even buy you a virtual pint) for some advice.

My 1986 2.0i Granada auto occasionally 'hunts' at idle. It sometimes causes the engine to stall, but that's quite rare. It can also idle at quite high revs in neutral and, conversely sometimes at low revs. It's more annoying that anything. I bought one of those Gunson diagnostic thingies (told you I wasn't technically minded!) and it gave the fault code for the air flow meter. So, I replaced that (with one from a scrappy admittedly) which didn't work, so I tried again (another scrappy) and still the problem persists. Have I been unlucky in buying two knackered air flow meters? Or is something altogether more worrying the matter?

Also, whenever I acclerate quite hard, there's a worrying metallic chattering from up front. I know that the heat shield is a little loose - is it that or should I get my chequebook out?

Thanks for your time, over to you...
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Tue 15 Apr 2003 22:53
Rough idling Granada - frostbite
I had 2 (2.8i) Scorpios that both occasionally 'surged' at idle - being auto's it sometimes made life interesting and I learned to always leave a good space behind other cars at lights etc..
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Tue 15 Apr 2003 22:59
Rough idling Granada - greaser pv
Idling fault is probably the idle valve, it's a 4-5 inch cylindrical unit usually attached to the big air intake pipe , it has an electrical feed via a small plug and an air pipe at the other end. Remove it and spray the inside with carb cleaner shake it vigorously and repeat. I bet that cures the fault . As regards the other noise it may be the timing sensor touching the front pulley, or it's just pinking , the timing's too advanced or you've bought cheap petrol.HTH.
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Wed 16 Apr 2003 09:37
Rough idling Granada - jc
As the man says,clean the idle speed contrpl valve;on the knocking noise your ignition timing is probably still set for 97 octane fuel where current unleaded is 95.You need the timing set back about 2-3 deg.
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Fri 18 Apr 2003 15:25
Rough idling Granada - Rob the Bus
Thanks for your help, guys. I did clean the control valve and things have improved immeasurably. And, as I\'ve mentioned in the Texaco or Shell thread over on Discussion, I put Optimax in yesterday and the pinking has all but vanished.

Cheers

Rob



Watch out for squirrels\' tails. Far too bushy for my liking.
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Fri 18 Apr 2003 20:31
Rough idling Granada - Nortones2
RTB: if you persist with the Shell fuel, maybe you could comment later on the effectiveness of the claimed detergent content? Carbon deposits in the combustion chambers could also be a factor in the pinking/roughness. If the fuel cleans up the engine, as is claimed, maybe the pinking etc will go totally. Anyone got a spare endoscope to look at the Ford piston tops?
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Fri 18 Apr 2003 20:59
Rough idling Granada - Nortones2
PS: see www.apea.org.uk/news/item.cfm?NewsItemID=233, for some comments re engine deposits.
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