Warm Start Problems

Hi-

My wife's 01 passat wagon (1.8T) has been having warm start problems
lately. Car starts fine in the morning but sometimes after a short
trip it will barely start. Eventually it does start up and seems fine
after that.

We had new plugs, filter, oil change and the battery replaced. Seemed
better for a while but just happened again this morning (And i got an
irate call at work : -(

Any ideas?

Regards,

Bill

My 94 Jetta GL is having the same sort of problem. It cold starts fine
and runs great, but after the engine has had time to warm up, it starts
really hard. It will turn over, but almost immediately stall unless I
hold my foot on the gas and keep it above 1300RPM. It will continue
this behavior until I've driven it a little way and then it idles
normally. It doesn't sound like it's starving because it will still
rev fine, it just won't idle.

I talked to a guy and he said there might be a bad sensor (something
like a cold start sensor) that is supposed to tell the injectors that
the car is warm so the car is flooding. I was also wondering if the O2
sensor might be bad because they tell the computer how to adjust the
fuel mixture but only after they've warmed up enough to start working.

I haven't tried either, I've been too busy but I was wondering if
anyone has any ideas.

Coolant temperature sensor is one place to look. This happened to a
friend's New Beetle and I believe he said that was the culprit.

Byron

On 9 Mar 2006 06:32:02 -0800, "Bill" > wrote:

>Hi-
>
>My wife's 01 passat wagon (1.8T) has been having warm start problems
>lately. Car starts fine in the morning but sometimes after a short
>trip it will barely start. Eventually it does start up and seems fine
>after that.
>
>We had new plugs, filter, oil change and the battery replaced. Seemed
>better for a while but just happened again this morning (And i got an
>irate call at work : -(
>
>Any ideas?
>
>Regards,
>
>Bill

I replaced the coolant temp sensor on my Jetta and it fixed the
problem. Go to your dealer and ask for a Coolant Temperature Sensor
and the O-Ring that goes with it. It was a quick fix. Took me about
15 seconds.

On the 94 Jetta, the CTS is a 4 pin sensor that lives in the water out
hose on the top of the engine.

In our '99 Passat wagon 1.8t we had difficult hot starts. Turned out to
be the vapor management valve, and was replaced under warranty. I think
the dealer said there was an issue with them. That is probably what the
other respondent referred to--the engine controller compenstates fuel
injection for how much vapor is coming from the evap system (charcoal
canister), so if that is screwed up it might use too much or not enough
fuel during starts.

We noticed the problem for sure if you filled the fuel tank while the
car was hot and the tank very low. Then it would be hard to start. It
started, it just took a while of cranking to get it started, just as if
it was "flooding".

They also replaced the MAF sensor (under warranty) in the debug
process, but that wan't the problem

Bill wrote:
> Hi-
>
> My wife's 01 passat wagon (1.8T) has been having warm start problems
> lately. Car starts fine in the morning but sometimes after a short
> trip it will barely start. Eventually it does start up and seems fine
> after that.
>
> We had new plugs, filter, oil change and the battery replaced. Seemed
> better for a while but just happened again this morning (And i got an
> irate call at work : -(
>
> Any ideas?
>
> Regards,
>
> Bill