Pierburg 2e3 automatic choke

[PaulFDennis]

Many years ago we had a 1987 T25 Caravelle with the 2.1L fuel injected engine. Once the children had grown up and moved on we reluctantly sold it. Now retired we have just picked up a 1991 T25 Autohomes Komet in good, serviceable condition with a 1.9 DG engine. It had a refurb engine less than 1000 miles ago. The automatic choke wasn’t functioning at all with cold starting and idle all over the place and very lumpy running. On investigating I noticed that when moving the choke flap the hex nut at the end of the autochoke housing rotated. Ergo the bimetallic spring was rotating and thus not able to be tensioned correctly. On seeing this I rotated clockwise the hex nut at the end of the unit until the choke flap closed with a 3mm gap then pushed the nut in and gave it a slight tap with the spanner. This seemed to lock the hex nut in place such that when I pulled the flap open there was sufficient spring tension to close it again when released.

After replacing the pancake on top of the carburettor and turning the ignition the engine fired instantly and settled into a steady idle. Putting the engine under load the van pulled away smoothly without any of the hesitancy that was apparent before the choke worked.

My question is the operation of the choke unit I’ve described correct and is the hex nut supposed to rotate when pulled out and the be locked into place when pushed in? I couldn’t find any discussion in the forum, in Haynes manuals or anywhere else about the setting up of the bimetallic spring and its housing.

It’s good to have another T25 and I hope we keep this one a long time.

[PaulFDennis]

I’ve just discovered itchyfeet’s Wordpress site and the absolutely excellent information and photographs concerning all aspects of the 2e3 carburettor. I see I was partly right about adjusting the bimetallic spring tension but didn’t realise there was a grub screw. I assume this had worked loose and the spring could rotate. My bodge was to set the spring tension and then tap the hex nut in to lock it. Now I can go back and do it properly.

Should have looked harder in the first place but glad I’ve found itchyfeet’s site now, as well as the amazing resource club 8090 is.

[T3_Rourke]

Any chance you have a link, I had a similar issue and ended up replacing the auto choke from a different Carb found from marketplace. Could ideally do with getting it rebuilt and being able to keep it as a spare. Got two in total in parts stripped for bit's in the garrage