Re: Cold start valve question

[DMCVegas@xxxx]

Leaving the Cold Start Valve unplugged won't do much of anything, let 
alone prevent a hot start problem. The purpose of the CSV is exactly 
as it implys. The valve is used only when attempting to start a cold 
engine. Quick run thru: When metal is cold, it contracts. Thus when 
an engine is cold, it contracts, and thus has more friction. The CSV 
is basicly the equivalent of a choke for a carburetor. It shots extra 
fuel into the system to create a richer mixture to counteract the 
additional friction. As you have already noticed, the valve is 
electrical. So as soon as it recieves an electrical current, the 
valve will fully open.

What a "hot start" problem is:

The offical name of the fuel injection system is a BOSCH K-Jetronic. 
It is known as a mechanical, or Continuous Injection System. An 
Electronic Injection System works on the same principal as the CSV. 
But rather than wide open, the electrical pulse cycles to control the 
fuel flow/amount. The CIS system doesn't need any electronic 
components to operate. The injectors are opend via pressure. The 
higher the pressure, the wider the valve opens to allow more fuel 
thru. Since high pressure is whats needed to open the valves, the 
pressure has to be maintained. A check valve, and a fuel accumulator 
are both used to keep the pressure while the system is off. If the 
pressure is not kept, then the system needs time to "refill" itself. 
In otherwords the fuel pump has to rebuild enough pressure in the 
system to force the fuel injectors open to feed the engine. That is 
what happens when you have a hot start problem.

How the CSV starts a hot engine w/a "hot start" problem:

When you have a hot start problem, the engine is being starved. Since 
the CSV is electical, it can open up w/o a specific pressure. That 
means that what ever fuel is in the system at the time, can be dumped 
into the engine. So in other words, the CSV will feed the engine 
untill the regular injectors are ready. BUT, within a few seconds, 
the CSV can also flood the engine too. The CSV is only designed to 
operate for a few seconds when the engine is first started. And only 
when the engine is cold at that. It may be a small item, but that 
little valve can dump ALOT of fuel into the engine. And we do mean 
dump in the literal sense of the word.

Bottom line: If the CSV is left unplugged, you won't notice a thing 
when running you engine, or starting it warm. If you try to start the 
engine cold with the CSV unplugged, you will have difficulty. But 
that will be the only symptom you have.

I didn't mean to go this in-depth about the fuel injection system 
just to explain 1 little item, but it was the only way it could make 
sense.

-Robert
vin 6585