must find a way to get home without fuel regulator:100Q fuel prob

[SJ]

> From: "Denis" <sparkplugvw at hotmail.com>
> Subject: Re: must find a way to get home without fuel regulator:100Q
> fuel prob
>
> Finally the vacuum is OK. there was a units problem only. Its 9.5 psi or
20
> inchs Hg as any normal idling engine.
>
> If i can trick the fuel distr. (push with my hand)and shoot fuel to the
> cylinder then why when i crank it it does not shoot ??? (it s more a
comment
> than a question Frederick)

**** Why it does not work by itself? Why do you need to "assist" the fuel
distributor to make the car fire up?

The sensor plate is calibrated to provide X amount of fuel when you start
the engine. The plate lifts Y amount to provide X amount of fuel for the Z
amount of air flowing past the sensor plate. Everything is nicely calibrated
to provide the right fuel mixture. The cold start valve provides W amount of
extra fuel for starting purposes.
All this works perfectly  . .. IF . .the system fuel pressure is at 90 PSI.

If system fuel pressure is at 60 PSI(as in your case), the injectors wont
provide X amount of fuel.
The sensor plate lifts Y amount, the air flow is Z amount, but because the
fuel pressure is 1/3 lower than what its supposed to be, the amount of fuel
delivered by the injectors is (X-a) . . . it aint X amount but something
less. That something less(a) will lean out the air/fuel mixture so that the
car will not start.

When you lift the sensor plate by hand, you are changing Y . .the sensor
plate lift amount. The fuel distributor valve opens more - allowing more
fuel to flow thru the injectors.
The amount of air flowing(Z) is still the same. Fuel amount(X) is greater
because sensor plate(Y) is higher. You just compensated the air fuel mixture
so the engine can start.

Once the engine starts, it may keep on running on the lean mixture when the
sensor plate returns to normal when you remove your "hand assist".
Starting is hardest to do because it requires a rich mixture to start. Your
"hand assist" provides that extra fuel by lifting the control plunger in the
fuel distributor. You are manually compensating for the low system fuel
pressure.

Think of the problem in another way.
Your car wont start. Everything checks out, but it still wont start.
If you spray in starter fluid, it starts and runs ok.
You check the sensor plate, and its sticking . .. it wont rise enough (Y
amount) for the volume of air(Z) flowing past it.
The sensor plate rises only Y-b for the amount of air flowing(Z). The
control plunger wont rise enough to provide X amount of fuel - fuel is only
X-a.
The car wont start . . . too lean a mixture. Starting fluid richens the
mixture so the car starts. Once the engine fires up, the sudden large
increase in air flow will break free the sticking sensor plate.
Once the car is running, the sensor plate rises above that spot where it
sticks and the car runs normally . .. until you shut off the engine and try
to start it again.

The principle for failure to start is the same, not enough fuel for the
amount of air - lean mixture during starting. The reasons are different -
low fuel pressure vs sticking sensor plate. But the solution is the same . .
richen the mixture. You did it by manually raising the sensor plate. In the
other case, you spray in starter fluid.


SJ
85 Dodge PU, D-250, 318, auto
85 Audi 4k - - sold but still on the road
88 Audi 5kq
90 Audi 100q