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Cold start problems
Topic Started: Mon Jul 13, 2009 10:59 pm (657 Views)
Andy
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Part of things
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Not sure if this is a 'problem' as such, but when I start the car from cold the it idle's really wierd.

It will idle at about 1200rpm, then drop to about 400 rpm, then back to 1200, then down to 400. It basically sounds like I'm revving it but I'm not. It didn't used to do this. It always just used to idle at 1200 rpm, then drop gradually down to about 700 once warm.

Any ideas??

THanks
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balamb37
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Grumpy Old Grampa with Dog
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Hi Andy,

The first thing I would do is to check ALL the 'Vacuum Hoses' specially at both ends as they tend to split around

the end of the pipes that they slip on to, also check the length by squeezing for splits along the length,

also for porousness,

all these things can give you an unregular or high tickover, (weak mixture) ;)

It sounds like your problem as you've had a high tickover for some time before and it has got worse,

Your tickover should be 800.

Hope it is one of these as it is an easy and cheap 'fix'.

Cheers Barrie.
Edited by balamb37, Tue Jul 14, 2009 11:04 am.
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Stempies
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Hot Lips
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Not had engine cleaned recently have you??

Had same problem on a Jag i steam cleaned long ago!!
I buggered the air flow meter!!!! :$ :-/
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austria42
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Try checking also the OVP and Air Idle Control Valve. The ECU is controlling the idle speed normally via the airflow and cold start injector. Worth checkg the injector as well. Cold the idle should be 1000rpm, the dropping to 800 rpm, as it is on mine
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alogaparaloga
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crazy mind
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Andy this is normal for our cars in very cold conditions. The reason is that 2 pin Idle air valves do not provide feedback to the ECU. This happens only in the start up, so the management is running on look up tables (preset values by the factory) of various sensors. Air temperature, coolant and air/fuel metering unit.

A clean up of the idle air valve and AFM unit internally with carburetor cleaner would help to reduce the fluctuation of idle when cold, but keep in mind that this is the way the system works on our cars.
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Andy
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Part of things
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Thanks for the help guys. Im going to have a look tommorrow. I've found some information on the location on the idle air valve etc so I will give it a clean and see how it goes!
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Rich27
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Admin

You can adjust the mixture with an allen key through the top of airbox,
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balamb37
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Grumpy Old Grampa with Dog
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I would say you shouldn't touch the adjustment screws, 'Idle' or 'Mixture' by so doing (if it works) you are only getting rid of the Symptoms but not curing the problem, which to me still sounds like a leak letting extra air into the induction somewhere, and the most plausable is a faulty vacuum hose. and that is a common occurence with ALL190s.
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