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[bobbber]

Guys,

The throttle bodies on my car look spot on. A teeny touch of the accelerator bar opens them both at what appears to be identical times.

However, this slight touch results in the engine nearly dying. Like Paul Hide before, the engine idles perfectly and revs lovely. It's just this small initial press of the accelrator that kills the engine.

I thought it might be the alignment of the throttle idle/FOT switch. This is on correctly when idling, but the slight accelerator touch turns this off. I thought this may need to be on through the first couple of degrees of rotation to ensure the engine gets enough fuel at a point where the air flow is so low it might be difficult to measure. So - I thought this was my problem.

BUT, the manual says only for a maximum of 1 degree, which has made me think again.

Does anyone *actually* fully understand these bloody things or what?

Also, am I right in saying that that idle switch is there simply because air flow is so low when at idle that the ECU can't measure it accurately? If not, why is there the whole elaborate system to deal with idle when drilling a hole in each of the throttle body butterfly plates would do the same job?

Cheerz,

Bob
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Fiat Bravo 165 Sport

[bobbber]

And another thing... is the idle actuator at the front of the intake manifold CLOSED when the throttle isn't at idle???

Bob
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Fiat Bravo 165 Sport

[Admin]

Hi

The idle actuator controls the idle speed, and can keep it constant (ie, hot, cold, running on 3, it will do its best to keep the idle speed at the right level) which holes drilled in the throttle butterflies (or holding them open slightly, or having a small bypass passage) cannot do.

As such the idle actuator should be open at idle, and beyond that shouldn't reall matter.

My P4 has a similar problem just off idle. My guess is that it is the throttle position sensor.

As to balancing them, you will only get a vague approximation by sight. Get some vacuum gauges to set them properly. These ones are cheap and have a good reputation:-

http://www.carbtune.co.uk/c.com/carbaccs.html

I have some of their older Mercury ones.

All the best

Keith
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