high revs 16v

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greendale65
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high revs 16v

Post by greendale65 »

Hello all, forget the arm rest still got the high revs on my
valver getting to the stage packing it in nobody seems to
have the answer to this.
thanks for looking.
:( :(

RobC
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My Cars: 1991 Citroen BX 16v
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Re: high revs 16v

Post by RobC »

There are a few different causes of this (presumably you mean unusually high revs at 'idle'). I've had similar problems on my 16v BUT there's no guarantee that it was caused by the same thing.

You need to approach the problem methodically and resist the urge to throw cash at incompetent garages who will gladly take your money to change random electronic parts at great expense, for little use. First of all you need to establish exactly what the symptoms are and when they happen, ie:

1. When does it happen? Engine cold/ engine warm/ outside temperature warm/cold, rain/sun, etc etc. Or maybe it just happens randomly? If you can, try to list all the variables.

2. How high do the revs go? E.g. if you did nothing would they just race upto 5- 6,000 and beyond, or does it just go upto 2,000 and stay there?

3. How do you 'cure' it temporarily when it happens? E.g. I have an intermittent high idle problem when the engine's warm that goes away if i blip the throttle. Or when it happens is the only solution to switch of the engine and start again?

Once you have clear answers to these questions, only then can you go onto the next stage and think about what might be causing it.
1991 Citroen BX 16v

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Kitch
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Re: high revs 16v

Post by Kitch »

Very difficult to diagnose faults over the internet, to be fair. It'll be one of a few things:

* TPS set incorrectly/faulty
* Air leak on intake side (manifold gaskets/hoses etc.)
* Dodgey ICV
* Sticky throttle cable
* Fuel mixture too rich
* Coolant temp sensor up the spout

And that's just me assuming it's fast idling or hunt when it's supposed to just be idling.
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1983(A) 16TRS (Rouge Valleunga) - 1987(E) GTi 16v (Noir) - 1990(H) 16Valve (Rouge Furio)

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Way2go
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Re: high revs 16v

Post by Way2go »

I've had this occur in the past! I guess we've got to remember the old girls are getting long in the tooth and lubrication dries and alloy parts suffer with some surface corrosion (you live by the coast I believe). :( I'm specifically talking about the throttle body here and what happens is that, because of this, the second butterfly which relies on spring pressure alone to close does not make it to tight shut.

Spray some 3in1 Penetrating spray onto the shaft of the second butterfly where it passes through the throttle body and manually work it backwards and forwards a few times carefully. It likely is all it needs! :D
1991 BX19GTi Auto

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Re: high revs 16v

Post by rutter123 »

You could try this approach, try spraying some carb cleaner around all the intake hoses pre throttle body and around all the breathers and any other hoses around the engine with the engine running, if the rpm's rise then you are getting closer to resolving this issue.
Bear in mind the hoses are getting on for 25 years old and do crack/perish-the smallest air leak between the throttle body and airflow meter will cause idle/high rev issues and all sorts of running issues, I had thiss on my gti and it was the cold start valve not closing properly which was the cause, it is a long process of elimination, prob best to start by removing all the rubber pipes and thoroughly checking them for splits before spending money on parts that will not cure your problem. Take note of al the above replies as well.
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greendale65
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Re: high revs 16v

Post by greendale65 »

Thanks everyone will go for these issues next week tied up 4 - 3 days
will sort this out spent all day at Hostpital yesterday taking car to garage friday
replace head light and beam focus get them to adjust clutch cable as well.
thanks all