[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Not starting after long drives

On 3 Nov 2003 at 9:54, Gamboa, Gary wrote:

> I took a drive this weekend about 40 miles, all
> highway. When I stopped for about ten minutes,
> the car wouldn't start again. Good crank, and
> begins to fire up, but then doesn't. After
> waiting about 20 minutes, it finally started.

This is a common problem, but it has no easy or certain solution. It's related 
to the "heat soak" after shutdown. This refers to the fact that once the engine 
is shut down all the heat from within the engine works its way out and soaks 
into the surrounding engine parts. In the case of our FI cars, this causes all 
the gas in the fuel ring to boil, leaving only vapor in those lines. Once the 
engine starts to cool back down, a vacuum is created in the lines which will 
then cause air to be drawn into the system thru any small leak that might be 
available, including thru the injectors since they are not likely to be air 

My first approach to this is to look for, and fix, any gas leaks, because these 
will be the larger air leak paths. If this doesn't do it, then turning the key 
ON and OFF several times may run the pump enough to refill the fuel ring. 
Pumping the pedal on 70-3 cars will help if you do it at the same time.  

If this is still insufficient, I have sometimes installed a small pushbutton 
under the dash which bypasses the fuel pump relay. Pushing this button will run 
the pump without running anything else. If you install this, you can actually 
hear the air bubbling up inside the tank as the pump runs, so you just hold the 
button down until the air bubbles stop and then start the car normally. This 
will take slightly longer than normal, because the injectors themselves will 
also still be full of air at first.  

I suggest that you run the pushbutton from the FP fuse to the output side of 
the FP relay.  

None of this indicates a problem with the fuel pump itself.  

Jim Adney
Madison, WI 53711-3054

List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]