T4 Circulation Pump Leak: Troubleshooting & Adjustment

Hello everyone,

I recently replaced the socket and shaft of the VEP (variable exhaust pressure) system on a 1995 ABL.

After that, the speed was increased by 300 RPM, and it was very difficult to bring it down to 900 RPM.

I also replaced the inner spring, as this is often a cause of poor idling, especially if it has become stretched during removal.

I've now adjusted the throttle lever by one notch as a test, but the idle speed remains the same, even though it should noticeably change. I had previously completely turned down the residual fuel adjustment.

What could be going on here?

Hi,

I'm not a VEP expert, and I've never even held one with a mechanical throttle cable.

For an electronic system, I would assume that the flow rate setting would need to be adjusted on the pump itself. I cannot determine whether this can be replicated in a mechanical system.

Regards,
Sure, here's the translation:

"Guste" is a German word that means "gust" or "gust of wind." It can also be used to describe a sudden burst of something, such as laughter or anger.

It's a good idea to mark the position of the throttle lever on the shaft beforehand. I would recommend taking each step back by one tooth at a time.