throttle delay, and irregular idle when cold

[scottyw]

Hi all,
I wonder if you can help me. I've had this ongoing problem with my '86 (watercooled) automatic petrol T25 with Pierburg carb. There seem to be two issues, not sure if they are related.

1. When the engine is cold, the idle is erratic, often stalling out when I start moving from stationary at a traffic light for example. If I gently 'pump' the throttle I can sometimes manage to bring up the revs and then everything is ok til I stop again.

2. When cold or warm, there is often (but not always) a power lag when I push the throttle, even at speed. The power will dip, van will lurch, and then pick up. Sometimes I 'pump' the pedal gently to help it through this.

This is proving a mystery. One garage said it was my choke unit playing up. But would that explain the warm running issue?

Any thoughts on this would be greatly appreciated.

Scott

[xpress]

i have had something like this and still somewhat at present, you can tell if your choke is working if the revs stay constantly higher for a while as the engine warms up then they drop, in my case i have an intermittent idle and when the van is cold it can stall, and also a bit of a delay or a lurch or two as it warms up.

top part of the carb cleaned with carb cleaner, and nipped down a bit tighter, helped but it's still there, i think you may have a tired carb, might not be the choke, could be an air leak and the gaskets might need changing between lower and upper parts of the carb.

[scottyw]

Hi xpress,

Thanks for your thoughts. I think you're right - it could just be an old and tired carb, seems more than just the choke.