My 300E won't start. I have fuel pressure because if I loosen the fuel
line to the cold start valve i get a shot of fuel spray from it. So the
fuel pump is outputting. However if I disconnect one of the fuel lines
to an injector and crank the engine, no gas is ejected from the fuel
distributor. What we be the problem with that? Thanks for your help.
Just to help you in how the fuel distributor and injectors work..
The injector valves will open at certain pressure difference, and the
flow will depend on the pressure difference. On one side is the vacuum
from the particular cylinder, and on the other side is the fuel
pressure from the fuel distributor.
The fuel pressure is equal to all the cylindres (injectors), but only
the cylinder, which is in the intake stroke (intake valve open), will
provide enough vacuum for the injector valve to open.
The pressure from the the fuel distributor is controlled by the air
mass sensor plate, which will move a plunger inside the fuel
distributor to control the fuel pressure to be proportional to the air
flow. No air flow will result in no fuel pressure (flow) to the
The cold start valve will simply add some extra fuel to the intake
manifold for a richer mixture during cold start.
In parallel to the fuel pressure control plunger of the fuel
distributor is the EHA (Electro Hydraulic Actuator), which will fine
adjust fuel pressure and thereby the mixture according to control
signals from the ECU.
If this is defective, it may provide way wrong mixture and thereby
preventing starting. I had this problem with two different EHA's. Once
replaced with a good one, it started right away.
I could of course also be other things, but I hope the explanation
will assist you in the troubleshooting.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.