going home this morning from work my bert started hesitating under accelaration and backfiring (i beleive, though more of a crack than a bang). i drove it home (under 2 minutes drive) and found that the automatic choke wire had come off, ok, i figure, it was just running with the choke fully on, no problemo, i reattach the wire and get in to go to the shops, but the problem persists, allthough even more severe, i limped home (once again, a minute away from home). idles fine, and once up to 35 mph it drives fine, the problem only occurs under load.

i've only had him a few months (and have no tools in the car besides a hubcap puller i made). so am about to go buy a rudimentry tool kit to keep in the trunk.

and as such i have no idea what the problem is (this is my learner bug, one i know the ins and outs i'd like to move on to a nicer car)

my guess is fouled plugs (and one cylander not firing), faulty coil (and hence no spark) or maybe timing. am about to buy a stroboscopic timing light (after we catch the train and get my girlfriends car). i wanted one any way, only just got the cash for it tho.

have i got no clue or are these the logical things to check? is there something blindingly obvious i have missed??

cheers

The backfiring bit tells me that it could be electrical, check the Distributor cap for cracks or spark plug leads for crossfiring or shorting out.

Roger.

if it is running on 3 cylinders u will notice the lack of powerand if u open the engine bay the engine will shake as it is off balance....but id say it sint this.....im not car expert and guys if u are feel free to correct me but it just sounds like your carby has something blocking a jet or tto much fuel getting thru........what carbie/s do u hav....? u could try replaceing plugs too
does it start ok?

my carb is a solex 34 PICT3.

starts fine, and idles A-ok.

i wondered about something in the jet, i have a spare carb (guy who sold me the car gave it to me) and i might try swapping them over if nothing else helps.

is it OK to pull the plugs when the engine is warm? something in my mind tells me no, but i might just be remembering the wrong thing.

Softop - electrical is what i figured (lack of spark). will check the leads (distributer cap is fine).

id wait for the engine to cool besides if its hot u will hav a hard time not burning yourself

i take it you hav a superbug judging from your carby :thumb good on ya (even if it isnt runng properly):P

i work as a baker so i'm pretty used to hot stuff actually. but thats a good point (i'm more worried about the car than personal safety... i wonder if that means anything)

Make sure your point gap isnt too large or small. This could also be the symptom of a faulty condensor. If you've not changed your points in a while change them and the condensor (not expensive and you know they are good).

To check its not fuel take the air cleaner off and with the engine SWITCHED OFF (that includes ignition) pull the accelerator. Can you hear a hiss from the fuel being pumped? Pull it quite fast!

Lastly when was the last time the valves were adjusted? Maybe one of the inlet/exhaust valves are tight! You'll find lots of tech articles showing you how to do this.

Did this fault occur over time, or all of a sudden?

I like to change the plugs when the engine is warm, not roasting hot it shouldnt burn you! Doing this your using metal expansion to make it easier to get your plug out. If you do it stone cold then theres more chance of stripping a plug thread.

Just my 2c worth without any warranties whatsoever.

Rob and Daves web pages are pretty resourceful for fixing all sorts of issues.

As with any problem, its a case of elimination to trace your fault.

Good luck!

Steve

the valves were adjusted 3 or 4 weeks ago (circa 150 miles). along with all the other usual tune up stuff (replacing the plugs etc).

didn't change the points though, might do that when i can get to VW shop.

will pull the plugs now and check the leads. and see what i can see.

and yeah rob and daves page is awesome (printed off their automatic choke adjustment and solex34PICT/3 diagram and tuning procedures)

and yes it's a super, and i love it to bits. wouldn't trade it for the world.

If the choke wire fell off while driving it had power going through it all the time it was off. If it fell to earth on the engine more than likely its burnt the wire insulation through and its sometimes earthing out on the carby causing your engine misses from a power failure to the ignition circuit.

remove the wire and check it properly and replace if necessary.

turned the choke so it's off all the time (just for testing) so i'd assume even if the wire burned out it shouldn't cause the problem to continue (should it?)

the plugs were covered in carbon, i cleaned them a bit (first with a rag then a little sand paper) this made the problem abate but it's still most definently there. i'll try and find the set of plugs i removed when i changed them and slip them in.

bugger, the old ones are just as crappy. *sigh*.

fuel is getting into the carby fine.
will check the wire carefully.

cheers

i pulled the distributer cap off and the top of the rotor arm (that copper(?) bar) seems to be corroded by something, there is a hole there almost as wide as the rotor arm at 4mm deep. can i get a new one of those or would i need a new distributer?

sorri i hav no idea....as i said im no mechanic:P

regarding idling ok but not full power

have you checked the fuel filter

sometimes semi clogged can idle ok but when the revs are up it staves the engine

also have yo checked that there isnt a second filter fitted which may have been over looked.

Also check that the coil lead is firmly seated at both ends.

hope you sort it soon

regards

sounds like the rotor button is stuffed. get a new one, only a few $. Also make sure the carbon brush and spring on the centre pole inside the dizzy cap is clean and give it a gentle tug so it makes good contact with the rotor when fitted. there should NOT be a hole in the middle of the top of the rotor.
good luck

sorry for the lateness of the reply, have been working 7 days a week, and have had no internet access.

anyhoo, replaced the rotor ($35)

there seems to be no problem with hesitating now (replaced the carby with one i had spare as well)

but it still backfires, it would apper (as the long grey streak on the lawn would testify) that it's only one side (one cylander?) thats backfiring as it only seems to come out of the right hand exhaust pipe (stock peashooters)

replaced the fuel filter as well (this one is clear so i can see into it - helpfull)

i'm still thinking electrical (have a new set of points and condensor, haven't put them in yet). I am close to taking it to a VW shop but that would be admitting defeat, and i'm not the sort to do that.

on second thought will whack in the new points&condensor tomorrow. (so very tired right now) and see how that goes, failing that it's to the VW shop with him later this week.

will let you know the fault when i (or the nice guys(i hope) at the VW mechanics) find out

thanks for the help

$35!!!???

For all I'd know

BUT;

Is the Dizzy loose/ moved?

check for an exhaust leak somewhere on the way from the heads to the muffler... backfiring would be most often heard when backing off down a hill and letting the motor slow you a bit, otherwise recheck your fuel filters (sometimes there is one hidden right up close to the tank and you have to scooch right up under the car to see it and its probably LOADED with shite, plus there's one more INSIDE the tank, don't fvck with it too much, but as a quick test take the fuel line off at the pump end and blow with your mouth with the fuel cap off your tank- you should hear the bubbling and it should be fairly easy, if not get it started with a hand pump or foot pump- it also loosens the crud a tad ) and DEFINATELY that your distributor is in the right place and doesn't move (10mm nut should be nice and tight, but not spanner-breaking tight) set the timing statically, engine COLD. STONE COLD. none of this strobe malarkey. your gold plated limited edition rotor button should help too. go and spring for a new set of bosch leads and distributor cap while you're there, it's nice to do for your bug anyway.

oh yeah, and while you're playing around, take off your stock peashooters and give it a rev sans pipes. it'll piss off your neighbours, but it's fun
invest in a set of thunderbird quiet pack extractors and j pipes. give yourself another couple of horsepower for fun

postal diarrhoea
check your spark: get some fatly insulated pliers and hold the coil lead with them about 10mm from where it goes into the distributor cap: have someone crank it for you (a couple of times will do) blue white spark = YAY! dull orange/red= yeeech...but it could also be the connections getting the juice to the coil so check you're getting 12 volts to the coil +ve with the ignition on (both red lights on, not turning over)

No plugs should be tight to remove or replace hot or cold if neversieze or copper coat is used on the thread of the plug every time their replaced