I seem to remember that there is a wiring problem from the factory, that
allows this, in the late cars. It was masked by the anti-run on device
that connects to the canister and is powered off the oil pressure
switch.
The carbon canister hook up doesn't sound right to me. I think the 80s
had two canisters originally. Probably not needed, but it may have had
an extra hose. I think, the side breather should go to the air filter,
and there should be some take off on the DGV to go to the canister.
What happens here, at least on SUs or ZSes is that the anti-runon valve
gets energized by the oil pressure switch on shutdown. That closes it,
stopping air from getting to the canister, creating a low pressure area,
that makes it 'pull' air from a high pressure area, the carb. Thus also
pulling gas vapor, and killing the engine. Convuluted? Yes.
I'm sure a 'real' Paul (Hunt or Tegler) will explain the full problem.
In the meantime, check out the pages of 'Bee and Vee' (Hunt) and the
Teglerizer.
http://www.teglerizer.com/mgstuff/index.html
http://www.mgb-stuff.org.uk/
or possibly the MGB experience. Skye hasn't done a lot there resently as
his car is completely stripped, but it has a ton of info as well.
http://www.mgbexperience.com
Paul.
Scott Bradney wrote:
> Help,
>
> I have a 1980 MGB that recently had the engine completely rebuilt but
> now it won't shut off it continues to diesel (motor on) after turning
> off the ignition.
>
> Here are the details of the engine 18V
>
> Pistons are .030
> Spark Plugs NGK BPR6ES gapped at .035
> Distributor is a CEI factory one with new (NOS) Amplifier
> Carburetor is a Weber DGEV
> Timing has been set at 10 BTD at 1,500 rpm
>
> The only emissions items on the car are the carbon canisters which are
> connected to the breather on the side of the block and the breather on
> the top of the valve cover.
>
> Things tried
>
> Change spark plugs have tried Bosch Super R0091, and NGK BP6ES
> Set timing to different levels (+ - 5 degrees)
> Change fuel type from 92% to 87% octane
> Re-jetted the carburetor to .060 on the right hand side and .055 on the
> left hand side
>
> The altitude here is 3,200 feet above sea level.
>
> Any suggestions?
>
> Thanks
> Scott
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