1. Home
  2. Volkswagen, hot (Aircooled)
  3. Dies at idle...do I need I new carburator?

Dies at idle...do I need I new carburator?

Just done my first engine out this weekend. I had a generator to replace, (along with fan attacched) and fan housing. My offcenter fan, broke my generator and cracked my fan hounsing. It was a little tricky since I did it all alone, andthe engine is still a little heavy :) No problem there, but I problem I use to have has agravated: the engine dies at idle. I suspect the carburator is to blame, since one of its mounting screws was loose, a little hamering didn't help much. Tried to weld the screw to the carburator, but i suspect it still aint fixed. When I'm tightening it with a wrench, there is no stopping point, looks like the screw comes down in every turn. It i pretty tight do, and the front screw is allright. I took the carburator and cleaned it. Befoe I mouned it, I used some guew that vulcanizes with heat in the carburator/manifold juntion to cover potencial leaks in that area. No success... No matter the tunning of the carbuator, if the choke is all opened, it dies. Of course I've tested with a warmed up engine.

Spark plugs are new, spark cables are new, current is flowing well from the coil and to the spark cables.

Probably the hammering of the screw didn't helped the carburator, even if it had that problem allready...

Do I need a new carbuator? I got a 34 pic-3. How much should I pay for one of those?

Any ideias?

Thanks!

MM '70 VW 1300 bug

Reply to
Manuel Macedo
Loading thread data ...

If the car drives fine, but doesn't idle, check your wiring on the idle cut off switch. I had a similar problem after changing my fuel filter. I found that the wire broke at the connection for the coil.

Good luck.

Reply to
Houdsie

No luck... Wire is fine :( Thanks anyway.

Reply to
Manuel Macedo

The idle problem doesn't connect necessarily to the pulled thread of the carburetor stud.

Anyway, first you have to fix the stud, as this is a more serious problem. You have to buy a helicoil insert to repair 8x1.5 mm metric thread (I'm not

100% sure if it is a 8x1.5, please someone verify this), a special tap and a special diameter drill to enlarge the hole. The tap, the drill and some helicoil inserts are usually sold as a set, at a reasonable price. Don't go for a complete set which has many different sizes, as it will be very expensive.

You need first to remove the faulty stud from the carb. Use two nuts locked together, to unscrew the stud from the carb body. Then use the special drill to enlarge the hole and tap it with the special tap. Then screw the helicoil insert with the tongue-side in, using a small flathead screwdriver that fits by the tongue. Use thread locking fluid on the helicoil. Then screw the stud in the helicoil, and you are done.

About the idle problem. Dying at idle means the idle circuit is not working. Either the electromagnetic cut-off valve is defective or not getting power (it must click when you toggle the ignition switch on and off). Or the idle jet or idle circuit passages are blocked. You need to dismantle the carb and use compressed air to clean the idle circuit.

The only reason to ditch a carb is if the throttle shaft bushings are excessively worn and you can't find anybody to get it rebushed at a reasonable price, or if it is bent / cracked / corroded. Not idling is not a reason to replace a carb.

Bill Spiliotopoulos, '67 Bug.

Reply to
Bill Spiliotopoulos

I'm thinking the idle problem could be the pulled stud. If the carb doesn't bolt down good, couldn't you be sucking in some air around the gasket and/or base of the carb ? Might also warp the bottom of the carb ?

Randy

Reply to
Randy

I've grinded the bottom of the carburator to even it out, tried to tighten itthe best I could with the resorces I have... Still no success. Went to the store and they told me they get me a new carburator for

140 euros (~140 dollars), and that is one of the best problem solvers I could buy for my vw. Millage, problems, etc. I'm tempted... to tired of working on the car,and not enough driving it. The carburator they have is one of those brasilian ones. Any toughts on those? Mineis really tosted...

Thanks MM '70 1300 bug

Reply to
Macsoft

I would first dismantle and clean the carb's internal passages and jets with compressed air before going to a new carb. The idle circuit gets blocked fairly regularly, depending on the air filter you use, the condition of the tank and fuel lines (due to rust particles carried by the fuel). It doesn't make any sense to buy a new carb once or twice a year every time the carb needs to be cleaned to idle.

The carb does not need to be tightened with too much force on the manifold. Just enough force so that the nuts won't come loose. It would even work and idle fine if it was left just standing on the manifold with the nuts removed, because the vacuum of the manifold holds it tight in it's place during idle.

Bill Spiliotopoulos, '67 Bug.

Reply to
Bill Spiliotopoulos

Another thing,

Do you have a 1300 or 1600 cc engine? The 34-PICT or replacement carbs are jetted for a 1600cc engine. If your engine is a 1300 dual port fitted with a 34-pict 3 carb you may have to switch the idle jet of the new carb with a larger one to make it idle properly, because the 1300 has less manifold vacuum at idle than the 1600.

Bill Spiliotopoulos, '67 Bug.

Reply to
Bill Spiliotopoulos

I've got a 1300 DP with a 34 pic3 (well changed it allready for a bocar 30/31). That could probably be it, cause the 30/31 comes with an adaptor to work on the 1300 DP manifold. In the store they told me, if I has a 1600 all I need was to unbolt the adaptor. Never told me about the idle jet. What is the idle jet exactly, and where is it located, how can I switch it? (sorry, english is notmy main language) I could probably try to use the idle jet of the 34 pic3 on the bocar

30/31 and seeif my problem is solved.

Reply to
Macsoft

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.