running misfire 1.9 petrol Pierberg carb

[phil300161]

Hi all drove my Gipsy back from Germany no problem 700 miles last week went out and it stopped turned over the engine for ages then it started and went half a mile and stopped again it sometimes ticks over ok then stops, other times it revs up ok then ticks over ok for a while and stops.
So far I've looked at the club 80/90 threads, pierberg threads done all I can find, and looked in the float bowl= all clean removed the jets = all clear
the red diaphragm on the side of the carb=ok, the electric switch on the side of the carb= removed tested cleaned put back on
it ran & revved up then stopped, new fuel line from the tank to pump fitted, fuel filter new can blow into both ways with no resistance, fuel entry to carb & float all unblocked and clear, new longer than the old alternator rod that operates the fuel pump new, I have removed the fuel line from the carb & turned the engine over it spurts out fine, when the throttle pedal is pressed it squirts in the carb fine. I have a new fuel pump & spark plugs coming from heritage vw Tuesday
What else can I try???

Thanks Phil

[kevtherev]

Ok
Does the engine stall only when the choke is fully open?...


I think this is an ignition problem though.
You seem to have eliminated fuel delivery as a possible suspect
I would investigate the ignition system.

[phil300161]

Hi Kev no I got a can of fuel today ran a pipe to the pump still no difference it fired a few times, managed to get it running by getting my son to turn it over while I opend the throttle by hand and squirted WD40 into the carb held the revs for about 5 minutes to warm it up but as soon as I let go of the throttle it stopped, then wouldn't start without a squirt of wd, Ive ordered a pierberg carb rebuild kit new disy cap, rotor arm & black box module from brickwerks, new plugs & fuel pump from Heritage
I have removed the solonoid on the side of the carb there was some dirt in the end I cleaned it tested it the inside bit opend up ok it did run better for a few minutes then stopped and wouldn't start
I'm sure its a simple thing but frustrating to find atm

[kevtherev]

You are going about this the right way.
elimination will eventually reveal the reason

One thing..
Did you check for spark each time it refuses to restart.. if there is a spark then we can eliminate a lot of stuff
I had an issue with the king lead arcing in the coil socket... took ages to track it

[kevtherev]

This solenoid circuit is activated with the ignition.
may need to be investigated

[phil300161]

Yes its got a realy strong spark, tried a spark plug in, but might give it a try when it wont start on the key again

[phil300161]

Pleased to report in, its runs & revs up not sure what it was for anybody else that has the same problem, but for reference I removed the thin filter in the brass intake pipe on the carb [you can't see it its inside] got a pierberg rebuild kit for the carb, new rod that pushes the fuel pump, new fuel pump, new fuel line from tank to pump, new rotor arm & distributer cap, 4x spark plugs, new black box electronic module, new air filter. Not cheap at £150plus but hopefully wont break down again

[kevtherev]

result

[phil300161]

Would you believe it its done the same thing again been running fine then started to miss a few times, hesitates when I put my foot down if I change down a gear seemed to clear and rev and go ok, then nothing just dies to a stop, turns over for ages then fires goes half a mile then stops again managed to limp home and took of an ht lead and put a plug in reved it up on 3 cylinders the spark is bright then on tickover fine but after 5 or so seconds it just stops, it starts up again ok the fuel filter is full up, everything I could replace is new. I am taking the carb off again tomorrow anything else I can try???

There is a rev counter fitted that doesn't work and a old alarm that was fitted years ago, might try a live wire to the pierberg fuel shut of valve, there are a few aftermarket wires in the black plastic box in the engine bay but not sure what they are for
Any body got a spare 1.9 petrol watercooled pierberg I can try

[kevtherev]

start again
follow the elimination process
fuel delivery first
then clean out the carb.

don't assume...check.

[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, Ive wired a light to the fuel cut off valve on the side of the carb that stays on so the live is ok, Ive run it on 3 cylinders with a spare spark plug loose it sparks with a crisp blue spark even when it stops & turns over to try to start, only thing to change now is the coil or try another carb
Any more ideas

[itchyfeet]

I have a shed full of dg bits including a carb do you think it will drive as far as southampton happy to spend a couple of hours swapping bits

[MidLifeCrisis]

Assume you've checked all the usual sources of vacuum leak?
Does it always stall at idle (or can it also stall while being rev'ed?)
I can't think of a good way to test this but are you sure that the float chamber has fuel in it when it stalls (the only test I can think to do is manipulate the throttle 5-10 times after the engine has stalled and ensure that you are getting squirts of fuel from the accelerator thingie - that might give a bit of reassurance that the float chamber still has some fuel in it)
Also - what tests have you done on the dizzy main body? Could the hall-effect sensor be playing up?

[kevtherev]

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.

[phil300161]

I have a shed full of dg bits including a carb do you think it will drive as far as southampton happy to spend a couple of hours swapping bits

Had the carb apart again cleaned & blasted with carb cleaner
Drove round the block today still stops every quater mile or less when it stopped it was like it ran out of fuel had my foot on the accelorator but nothing while it stopped I checked the spark plug- good spark, put a light into the carb and opend the throttle saw a squirt of petrol, the inspection hole in the float chamber looked to have fuel kept turning it over then it started so went another 300 yards and stoped again, put a voltmeter to the positive on the coil that had 11.57v, I also ran it from a 5lr fresh fuel can with the fuel pipe and return pipe in the can bypasing the tank
itchyfeet if you have a spare pierberg I can borrow I can collect it dont think the gipsy would make it

Assume you've checked all the usual sources of vacuum leak?
Does it always stall at idle (or can it also stall while being rev'ed?)
I can't think of a good way to test this but are you sure that the float chamber has fuel in it when it stalls (the only test I can think to do is manipulate the throttle 5-10 times after the engine has stalled and ensure that you are getting squirts of fuel from the accelerator thingie - that might give a bit of reassurance that the float chamber still has some fuel in it)
Also - what tests have you done on the dizzy main body? Could the hall-effect sensor be playing up?

no not checked the dissy not sure how to do that, there is a good spark at the plugs, Ive sprayed WD40 round the base of the carb and on vaccume pipes no difference in engine revs