Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing 3.9 v8 cuts out at bottom of a hill

Pleased that you appear to have resolved the issue, however I do have some thoughts. From your description of the setting of the base idle the blanking cap that covers the adjuster seems to have been removed suggesting someone altered the base idle previously which begs the question why? I assume your idle was running low before you made the adjustment? Have you checked the condition of the Spark plugs? I would also make sure the timing is correct. The thought is that adjusting the base idle is covering up another issue.

Very simple to do.

Locate the Allen bolt adjuster on the top of the throttle body.

Get the car warm then whilst on tickover clamp the hose on the right that goes from the throttle body to the plenium chamber.

At this stage the car might cut out, like mine barely idle, or if it sits nicely at 600rpm it’s ok.

If you need to adjust make sure you have a pen and paper to note your adjustments so that if it all goes wrong you can return to original setting.

I used a T handle Allen so I could accurately measure half turns which to open the air screw is anti-clockwise. Mine was three half turns.

Apparently you need to watch for the fan kicking in as this affects the rpm when you are trying to set it.

Hope that makes sense.

thats the one, and its the pipe directly by your finger.