Pierburg stutter

Post by **skell** » 22 Dec 2005, 22:38

After rebuilding my pierberg 2e3, I now have a slight stutter when first stepping on the gas when engine is warm, (ok when choke is shut) just as I start to press the gas pedal, clears when pedal pushed far enough to work accelerator pump or after about 1/2 second. I have just replaced part load enrichment valve and accelerator pump, accelerator pump works ok as far as I can tell by watching. could be a worn spindle, but I think this can be ruled out as I didn't have this problem before stripping and rebuilding carb.

any ideas? anyone know how/what part load enrichment valve does?

thanks

Post by **Ye Olde Syncrospares** » 23 Dec 2005, 09:14

can you see the acc pump squirt fuel when operating the lever manualy,cj.

Post by **stuckin88** » 23 Dec 2005, 13:46

I had this problem intermmitantly with mine(hadnt stripped carb tho) I finally solved it-the trunking that bolts to top of carb with 3 studs has the engine breather attached to it-the fumes from the engine breather coated the inside of this trunking with hard oily deposit--bits of this broke off & blocked the carb jet temporaly---clean out inside of trunking-not easy cos its so narrow-best to use an air line

Post by **tweeks** » 29 Dec 2005, 15:22

I've got a 2E4 Pierburg and it also stutters slightly when you go through to the accelerator pump section of travel. I can see fuel squirting through when the pump is operated manually so it's not that, I've just got used to it happening. It feels like too much fuel or the wrong mixture is being passed into the cylinders when the second choke starts to open. I'll watch this thread carefully ro see if you get any more advice.

Post by **skell** » 01 Jan 2006, 10:21

thanks for replies
CJ- accelerator pump works fine, stutter is before accelerator pump kicks in.
will go for some more cleaning to see if this sorts it, thought I had got it very spotless though.

Post by **trundletruc** » 02 Jan 2006, 20:39

Mine has always had a flat spot when you press the accelerator slightly. (I have had my van for 10 years) I checked the amount given out by the accelerator pump and in order to get it as spec.(Haynes manual) I had to put it right on the top of the cam.

This made a slight difference but there is still a bit of a hesitation with slight accelerator movement.

Must try the Weber carb sometime as the second choke on this is worked mechanically rather than than by vacuum as on the Pierburg.

I sometimes wonder if it could be to do with the distributer advance and retard mechanism?

Post by **Simon Baxter** » 03 Jan 2006, 20:31

Clean the progression holes with compressed air.

Post by **trundletruc** » 04 Jan 2006, 21:56

Thanks Simon!
Which ones are the progression holes? Are they jets or not?

Post by **skell** » 05 Jan 2006, 13:33

'which ones are the progession holes'
just what I was gonna ask, but I'm also thinking the accelerator pump arm may be out of shape, got another one here off a grotty carb so will compare the two at the weekend when carb is coming off again
thanks all

Post by **toomanytoys** » 05 Jan 2006, 15:07

A major "fluff" when just pressing the accel can be caused by the vac advance unit on the distributor not working/not connected/vac leak..

Disconnect the hose from the back of the carb (hose may be perished) and suck on the unit.. you should get a nice vacuum.. if you can suck the world in, thats your problem..
worth taking the dist cap off and seeing if the mech is actually working if you have good vacuum too..

A beetle vac advance unit can be fitted, but the holes need drilling out.. I think I used a 3 hole type last time!!

Post by **skell** » 06 Jan 2006, 13:53

thanks will add to the list of things to check, was working ok a few weeks ago when I stripped and cleaned dizzy.

Post by **futurecut** » 06 Jan 2006, 14:32

You did redo timing after refitting dizzy?

Post by **skell** » 09 Jan 2006, 13:24

all sorted now, was either down to accelerator pump not working soon enough (the old one may have got bent slightly I tried to fit wrong sized diapraghm) or some crap in the carb somewhere.

BTW early pierburgs have an accelerator pump with a shorter shaft on the back of the diaphrargm than the later ones. I got later one as replacement, but also had to replace the lever/housing that connects the cam on the throttle spindle to the accelarator pump.

Post by **skell** » 09 Jan 2006, 13:24

all sorted now, was either down to accelerator pump not working soon enough (the old one may have got bent slightly I tried to fit wrong sized diapraghm) or some crap in the carb somewhere.

BTW early pierburgs have an accelerator pump with a shorter shaft on the back of the diaphrargm than the later ones. I got later one as replacement, but also had to replace the lever/housing that connects the cam on the throttle spindle to the accelarator pump.

thanks for all the pointers

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