No idle at all

Hello all,

 I noticed a problem lately with the drivability of my '90 cabby with a Pierburg 2E2

On LPG when I slowed down too fast it would cut out - I got around that by slowing down / shifting down

When I went to the petrol station to fuel up I switched to petrol it died on me - no idle at all

To finally solve the problem I installed a NOS Pierburg 2E2 carb and everything around it

The Pierburg has all settings sealed with yellow paint

The manifold had a new gasket - coolant O-ring - new flange with a light coat of sealant some 500km's earlier

New one-way vacuum valve as well

The Idle control relay and TTV get 12V - I made sure with a spare set of plugs straight from the battery to bypass the fuse box

The manifold heater and electric choke get 12V as well - those coolant temperature switches work too - fuse 17 and 18 are ok as well obviously

New bended choke to wax thermostat hose too

Note that the carb came with all brand new pieces - like the TTV - Idle relay - Pull down unit - Wax thermostat - Choke etc.

The carb is earthed as it should be

The problem however stays the same - NO IDLE at all !
NO IDLE with LPG either since I fitted the new carb

It idles just when started up from cold - as soon as there chokes open up it dies - can't get it up to idle again since the choke is a bit open

When I keep the choke almost closed I can keep it idling

Any idea where I should be looking at ?

BerT3

http://www.clubgti.com/showthread.php?124945

and click the link in my signature look for the haynes 2e2 carb manual pdf document

Perhaps the lever that contacts the 3/4 unit needs to be adjusted, or the 3/4 unit idle adjuster on the back

also the base co will probably want to be tuned as well since its a completely new carb

Found the problem

The manifold to the head is leaking

When covering the car and spraying brake cleaner in the region of the manifold studs the RPM goes way up

Pity since I just had a new head installed after a head gasket failure

Parts are ordered and will be installed soon

BerT3

Found the air leaks at the manifold

2 bolts were shaken loose - retightened them

Still the same problem

Sprayed brake clearer around the manifold - no raise in RPM now

I suspect the vacuum non return valve to the brake booster now

I can remember I could suck it both ways

Could an air leak or non-return failure has that much of an effect on the idle - no idle at all in the second stage when the coolant opens the choke even more

It would explain the lower than idle rpms when slowing down / braking since it last ran

Any input ?

BerT3

the n-r valve will need replacing for sure, though it wouldnt cause idle issues all it means is if the engine cuts out you loose servo assistance straight away rather than the valve holding vacuum in there to help you stop.

if the servo was leaking that would cause it though, easy test take the servo line off and block the engine side. if that sorts the problem then replace the servo