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-   -   500SEC Fuel system problem (http://www.peachparts.com/shopforum/showthread.php?t=199782)

CamelotShadow 10-17-2007 02:48 PM

Quote:

Originally Posted by ctaylor738 (Post 1629331)
The vacuum connection on top is a vent and should not be connected anywhere it it's like anything I've ever seen.

On the WUR, you should have a connection on the back that goes to the intake manifold just below the FD via a three-way connector and a temp switch, and one in front that goes to a four-way connector.

I have seen a few 82 84 etc car & theyt have the top vac hose on the vent of the WUR so it seems it has some function on the older models

My car is a 5/82 Euro

Ok...After a long study of the WUR traced most of it

The top vac hose goes to a vent off of a rubber hose that connects the air idle control valve into the intake.
Mine is not the electric ICV
Its a bosch upright air idle control valve

Front of reg vac tubing is red but can't trace it

Back of WUR is a vac hose that goes into the top of a T vac hose which connects to one vent of a Thermo vac valve switch
the other t arm goes to the back of the intake next to the fuel distrib area.

Sharing that TVV is another vac hose that connects to the 4 way vac hose in the front.
That 4 arm hose also goes to a air inject valve before going into the intake
Also connects to distibutor valve & a red line I can't trace...

It has bee suspected somewhere in this line is the EGR???

Anyway car runs flawlessly

Starts like a dream when stome cold
I have started it 2 times ok when warm if I restart with 5 minutes.

Still having a bad warm/hot sa=tart after the car is driven
You can leave the car and hour or 2 hours & when you try to restart
its crank city

Yesterday one restart took 2 long cranks
The other was lots of cranking many times
until finally I sat a while
Then it started a died a time or two before it finally got running...

The car did sit for 4 years
& I have only driven it say 125 miles so far
but this is the only problem I have with it...

Will asks mechanic tomoorow

Its going in for plugs & to replace the broken Tvv which is bypassed
Still car runs fine
even better
but that warm/hot start is still the same
or maybe even worse since the tvv broke but I don't think thats the cause of it.

Closet I have come to understanding this is
after the car has been run
when its shut there is a slight residual fuel leakage
it pools & creates a sort of flooded situation...

Now thats fuel injectors
old
as they are
& $$$$
so trying to see what I can do to minimize this & live with it...
Hoping maybe its even something else.

CamelotShadow 10-28-2007 10:29 PM

Accumulator helped warm start
 
On advise of mechanic got a new fuel accumulator.
Was a $100 part so it was worth a shot

Does help the warm/hot starts but they still on not instantaneous like a cold start & do need a lil gas

Least there is much less cranking involved so its alot better.

Thing is I also had new plugs & wires & thermo vac switch installed
at same time so maybe those could have made for better warm/hot starts too.

Anywayits starting much better on hot/warm starts
so thats a good thing...

:D

Found this site
http://www.k-jet.org/articles_dbkjet.html#34

Difficulty starting engine only when warm

1) Cold start injector stuck open or leaking: basically, this test is the same as the test above for the cold start injector, but you must have the engine warm before you test it. If the cold start injector fires when the engine is at normal operating temperature, then you've got a problem. You can do the test for 12 volts across the injector plug to see if it's the injector or the thermal time switch causing the problem.

2) Control pressure too high or too low: If you are blasting unburnt fuel (black smoke) out of your tail pipe, then your control pressure regulator is giving too low of a control pressure when the engine is warm and needs to be cleaned or replaced as described above. If the control pressure is too high (less likely) then the fuel mixture will be too lean (too much air, not enough fuel).

3) Regular fuel injectors leaking: Again, this would probably be signified by unburnt fuel coming out of your tailpipe. If the injectors leak, then a bunch of gas flows into the combustion chamber when the car is sitting. After the car has been warmed up and has been running, turn off the car and pull out your fuel injectors and see if any are leaking. Be careful, the engine is hot of course. If they leak more than one drop every 15 seconds, they should be replaced. If all of the injectors are leaking by about the same amount, the rest pressure is probably too high, so see below.

4) Wrong rest pressure: The rest pressure is the pressure that the fuel system stays at when the car is not running. If it is too high (pretty unlikely), fuel will be leaking out of all four injectors. If it is too low, the car will have a hard time starting because there is not enough pressure at the injectors, but may eventually start. The rest pressure can be adjusted by adjusting the line pressure regulator, which is a component of the fuel distributor. As I said before, I am not going to cover the line pressure regulator in detail because you need a fuel pressure gauge to really do it right.


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