b230a - Some minor problems. Very annoying.

Hi! I did an engine conversion on my 1980 244DL, and installed a b230a where
there previously was a b19a.
I also have five gears instead of four, and I am now really happy with how
the car runs (when it runs ok).

Now I only have a few small problems to sort out before the car works how I
want it to.

This is a 1985 b230a with a Pierburg carburettor. I opened the carb. and
cleaned it inside, and
I also replaced the rubber-membrane. The carb. has oil.

Problem nr. 1:
When I shut off the engine, it keeps on running on it's own for a little
while after the ignition is off.
Sometimes it runs for just two seconds, and sometimes up to five-six
seconds.
The times it keeps on running for five-six seconds, I sometimes get a
strange sound at the end, and the engine sounds somewhat like a tractor.
Maybe this is because only one of the cylinders are active? Anyway, this
is very annoying.

Problem nr. 2:
Sometimes the car won't start. This problem does not accure when the
engine is still warm from running, but it happens mostly in the morning.
This can happen even though the car has been driven for a long while
(without choke) the night before.
I have removed the spark-plugs, and they definetly smell of gasoline. I
have also checked that there is a spark.
When this happens, the only way to get the engine running again, is by
towing it or by running downhill.

Problem nr. 3:
This is a strange problem, and this thing does only happen once or twice
a week.
When I start the car it can run ok, but suddenly something happens,
causing the engine's rpm to increase when I press the clutch.
I can stop in a roads crossing to wait for the traffic lights, and then
the engine's rpm will increase up to perhaps 4000rpm.
This is very embarrasing, and I would hope to find out what causes this.
When I open the hood and press the mechanism on the carb., it seems it
won't budge,
but if I keep on pushing with my fingers (thus forcing it back), the rpm
will decrease slowly until I've reached about 1000rpm.
Sometimes, if I press the pedal quickly and then let it go, the rpm will
decrease back to 1000-1500 rpm.
The days when this problem hasn't occured, the car can run just fine on
about 1000rpm.

I hope you have some suggestions on what to do here, because these minor
problems ruin the fun of the new engine.

Thanks in advance. =)

- Jan Rune Bjorkelo -

 

By the way, the sparkplugs are completely new.

- Jan Rune Bjorkelo -

 

From a point at sea, to the circles of your mind, this is Jan Rune
Bjørkelo:

Cars that are prone to this are often fitted with a fuel shut-off
solenoid on the carburettor to stop it happening. Check to see if you
have one - it will be a small cylinder screwed into the carb, with a
couple of wires going to it. Unscrew it and check the plunger moves
when you turn the ignition on and off.

Other causes can be:
Too low octane fuel
Carbon build up in the combustion chamber
Wrong type of spark plug
Over heating

How is your battery? Nearly all the energy from the battery goes into
the starter motor, leaving little over to make a spark. This is
especially true when the engine is cold. If the battery is going bad
there may not be enough energy left to make a spark, even though it
appears to be cranking the engine OK.

Wierd. Is your clutch pedal or cable somehow interfering with your
accelerator pedal or cable?


--

Stewart Hargrave

A lot faster than public transport


For email, replace 'SpamOnlyToHere' with my name

 

Problem nr. 1:
Could this be 'cause of wrong idling calibration? I can control the idling
with both a small screw on the intake-manifold,
and by turning the bolt which controls the min. opening between the carb.
and the intake manifold.
I have changed both of them, and I'm not at all sure if they are correct.

I have found out that the car usually starts fine when it's cold, but if I
wait until the afternoon with starting it, the problem occurs.
That means the engine isn't frozen anymore. Could it be that water appears
in there somewhere because of the freezing and melting?
Could it be a leak somewhere that causes cold air to enter the engine
through the night, thus making ice-crystals appear in there?

No, they are not interfering with each other. I guess the rpm is increasing
because when the clutch is pressed, the engine runs easier.
The same thing happens if the car is standing still, and is out of gear (in
free-mode)


- Jan Rune Bjorkelo -

 

hello jan

i had the same problems with my 83 240(b23a engine),and tried the same
things you did(cleaning,new membrane,new needle and seat)but nothing
cured the problems
i then bought a solex downdraft carb and manifold from a 87 240 with
b200k engine and all the problems were gone
fuelconsumption was sligthly lower and the engine idled much better
this was a bolt on conversion,the only thing not to forget is a wire
from the positive connection of the coil to the fuel cutoff solenoid
on the carb,without this it will not idle
also use bosch sparkplugs(w7dtc super or w78 super 4)and electronic
ignition from a b200k or b230a

Marc Brack
4* 960,1*740 16v,1*tatra 613-4

 

This problem is now solved. It was the wire to the solenoid on the intake
manifold that failed.
When I changed the plug to the solenoid, the problem was gone immediatly.
I did not have to adjust the idling to fix this.

Here is a picture of the failing solenoid:
http://breim.net/volvotmp/6.jpg

- Jan Rune Bjorkelo -