1985 4000S running rich and sputters when cold
 

After replacing and checking various major fuelsytem parts I finally
have the car running perfect when hot!

Here is the current problem:

When cold, engine starts immediately, but runs rough and sputters when
accelerating. Rich mixture and gasoline smell is evident.

Suddenly, after driving it about a mile, it forgets all about the
above and the engine runs a smooth as butter, with very good power.
Almost like a new car!

Also replaced the cold start valve. I am speculating the problem
is temperature related.

Any ideas anybody?

hm

Re: 1985 4000S running rich and sputters when cold
 

I've got the same problem with my '89 200TQ. Looking forward to seeing what
folks say.

> After replacing and checking various major fuelsytem parts I finally
> have the car running perfect when hot!
>
> Here is the current problem:
>
> When cold, engine starts immediately, but runs rough and sputters when
> accelerating. Rich mixture and gasoline smell is evident.
>
> Suddenly, after driving it about a mile, it forgets all about the
> above and the engine runs a smooth as butter, with very good power.
> Almost like a new car!
>
> Also replaced the cold start valve. I am speculating the problem
> is temperature related.
>
> Any ideas anybody?
>
> hm

Re: 1985 4000S running rich and sputters when cold
 

Might be an adjustment to the fuel distributor, maybe CO.
Might be set very rich and then when the loop closes the 02 sensor compensates
some for the overly rich condition.
I don't see it sputtering though. (scratching head)
Check the CO or FPR current when the engine is cold

Are you using platinum spark plugs in it? Try some Bosch tri-electrodes
(W7DTCs) and see what that does for it.
Could also be a weak coil.
All new ignition pieces?
New Spark Plug Wires? Might be defective but working better when they warm up.

just some thoughts!
later,
dave
Reminder........
Before you criticize someone, you should walk a mile in their shoes. That way,
when you criticize them, you are a mile away from them, and you have their
shoes. Frieda Norris

Re: 1985 4000S running rich and sputters when cold
 

On 13 Jan 2004 13:47:22 GMT, vwdoc1@aol.comANTISPAM (dave) wrote:

>Might be an adjustment to the fuel distributor, maybe CO.
>Might be set very rich and then when the loop closes the 02 sensor compensates
>some for the overly rich condition.
>I don't see it sputtering though. (scratching head)
>Check the CO or FPR current when the engine is cold
>
>Are you using platinum spark plugs in it? Try some Bosch tri-electrodes
>(W7DTCs) and see what that does for it.
>Could also be a weak coil.
>All new ignition pieces?
>New Spark Plug Wires? Might be defective but working better when they warm up.
>
>just some thoughts!
>later,
>dave
>Reminder........
>Before you criticize someone, you should walk a mile in their shoes. That way,
>when you criticize them, you are a mile away from them, and you have their
>shoes. Frieda Norris

Thanks, will check on those things as well.

have to admit, that I temporarely removed the Oxygen sensor from the
muffler tube and are using an old catalytic converter from my 84 junk
car.

Reason for that is to avoid damaging the new converter before fxing
potential fuel/ignition problems.

Perhaps I should just go ahead putting in a new converter (bonsal
perhaps) and re-install the oxygen sensor which is new.

This is a California car.

Re: 1985 4000S running rich and sputters when cold
 

There is a set-up procedure in the 4000 shop manual to set the "quescent"
setting of the
fuel distributer. It uses an ammeter to measure the current to the
electromagnetic "tweeking"
servo in there. You might also want to check the ground lead from the
engine temperature sensor as well. On my '85 4000Q, a stack of ground lugs
at the battery had developed a high
resistance and threw all the engine metering out of whack.

It also seems to me that an O2 sensor should at least be checked.


Gene

"wo" <nomail@here.com> wrote in message
news:j9a800hgq5td989v0pdqq9m14c0fpasnq0@4ax.com...
> On 13 Jan 2004 13:47:22 GMT, vwdoc1@aol.comANTISPAM (dave) wrote:
>
> >Might be an adjustment to the fuel distributor, maybe CO.
> >Might be set very rich and then when the loop closes the 02 sensor
compensates
> >some for the overly rich condition.
> >I don't see it sputtering though. (scratching head)
> >Check the CO or FPR current when the engine is cold
> >
> >Are you using platinum spark plugs in it? Try some Bosch tri-electrodes
> >(W7DTCs) and see what that does for it.
> >Could also be a weak coil.
> >All new ignition pieces?
> >New Spark Plug Wires? Might be defective but working better when they
warm up.
> >
> >just some thoughts!
> >later,
> >dave
> >Reminder........
> >Before you criticize someone, you should walk a mile in their shoes. That
way,
> >when you criticize them, you are a mile away from them, and you have
their
> >shoes. Frieda Norris
>
> Thanks, will check on those things as well.
>
> have to admit, that I temporarely removed the Oxygen sensor from the
> muffler tube and are using an old catalytic converter from my 84 junk
> car.
>
> Reason for that is to avoid damaging the new converter before fxing
> potential fuel/ignition problems.
>
> Perhaps I should just go ahead putting in a new converter (bonsal
> perhaps) and re-install the oxygen sensor which is new.
>
> This is a California car.