running misfire 1.9 petrol Pierberg carb

[phil300161]

Cleaned the carb all the jets looked ok, revs up ok for ages ticks over then just stops and takes ages to start again then runs fine, occasional slight misfire/cough then stops, the fuel filter is full, :

fuel starvation to me,
fuel pump still not delivering.

Hi Kev turned the engine over with fuel line to carb off seemed a good flow of petrol

[kevtherev]

well that's great news.
one more thing to cross off

so to be sure.
The cold engine starts, runs then after a few mins it stalls?
is the coil gettig hot?
when it stops and won't fire is there a spark at the king lead?

it very difficult to remotely fix things I'm sure you know so we can only suggest things then maybe you might see another issue.

I remember one fella had the fuel cut off connected to the choke heater...impossible to see unless you were there
keep trying

[phil300161]

Right today i'm buying a new coil & fitting an electric fuel pump, will report back

[phil300161]

Put an electric fuel pump on & new coil runs much better so removed the electric pump and went back to the new vw one still goes been round the block 3 times about a mile each time no misfires or stopping fingers crossed it was the coil all along looks like the og bosch one fitted from new.
Just got to persuade my wife its ok now

[phil300161]

Went for a drive today did about 4 miles and then it stopped same problem went 300 meters then would cut out no response from the throttle pedal it just dies to a stop, then I have to turn it over for ages it fires up goes another 300 meters and stops I checked for a spark while it stopped it has one the fuel filter was full up.
I have new plugs, cap, rotor arm, plug leads,spark plugs, fuel pump & pushrod, electronic ignition module, pipe to tank, filter, rebuild kit to carb, removed the filter in the brass intake pipe, new air filter,Bosch green label coil

I don't know what else to try, maybe fit the electric fuel pump again and the test light on the fuel cut off valve

I seems to go for a while after I have worked on it then the same thing happens, any thing I can try

[itchyfeet]

My guess is an intermittant electrical or ignition fault

I had a similarvproblem once cured by wd40 sprayed in the base of the dizzy after removing the rotor arm an cover
I assume the mechanical advance retard was getting stuck

Another possibility is avbroken wire
You have replaced all tge parts but you still have nearly 30 year old wires
Run a wire from the stud in the black box with a 10A fuseand connect to the coil black wire after starting disconnect before turning ignition off
This will ensure a good 12v supply
Also makesure the earths under the coil ae good as well as checking the brown earth from the ignition amplifier to tye engine block s good

Broken wires can measure ok with a multimter but when you pass a current they get hot and go open circuit

Sorr of the terrible spelling this tablet is chalenging

[kevtherev]

so the engine warms up choke comes off.
your engine stalls.
I am presuming here that all the possibilities of inlet air leaks have been eliminated?

[infidel]

have you checked the idle cut-off solenoid?
I had a similar problem and replacing the solenoid did the trick.

[ELVIS]

What itchy feet said^

Have you tried bypassing the ignition switch/wiring?

[itchyfeet]

Phil

i'm assuming the reason you thought it was fixed and went for thatlong drive is that you had it running while parked up for some time until fully hot and in never cut out.

if that's the case then i'd say the bypass air valve works and air leaks causing stalling at idle are less likely.

or did you just start go for a mile drive ( about 3 times you said) stop and let it cool down?

if the latter's the case then it may never have got properly hot, get it properly hot on idle until the fan kicks in and see if it ever stalls

[ermie571]

ok...may be being thick here....but what if the choke isn't closing properly...so after three miles..its running too rich and dying??

It would take ages to start.....

Have you checked compression on all four cylinders. My old Aircooled would do this...fine when cold...would just die when hot....found it was leaking air everywhere and had really POOR compression on 2 of the 4 cylinders....

Em
x

[itchyfeet]

Or too little fuel
Early reports were that it started when wd40 was sprayed in

Carb cleaner won't take dirt out of jets and you have now removed the last point of defence which is the conical inlet filter

Probably best now to eliminae carb by swapping it with my spare

[waltraud]

Coukd you have something the fuel tank that occasionally moves to block the fuel outket...rust..old grommet?

I had similat trouble and think it was a poor earth on the ign module but being erratic was hard to find. Could change plastic fuel pipe from tank to carb ...cheap and easy and one of the few things left alone?
Good luck, you will get there. [ELECTRIC LIGHT BULB]

[phil300161]

Thanks for your coments & help
It was the distributor, we put another carb on and it was the same so changed the dissy & it runns happy been for a long test drive no coughs splutters or misfires
Thanks to itchyfeet for his offer of help and to Steve from BUGS AND BUSSES PORTSMOUTH 02392 831539 who came round my house & sorted it proper old school mechanic who knows his VW's

[kevtherev]

The distributor is mechanical.. with a vac advance..and a hall sender.
what had broke?