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JacobTD, VW Mechanic
Category: VW
Satisfied Customers: 1070
Experience:  Vw Specialist
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1968 VW beetle: adjust..the throttle positioner..engine stalls..Vacuum

Customer Question

1968 VW beetle will not idle. When I tryt to adjust the throttle positioner, any thing under 2000RPM and the engine stalls. Vacuum to the throttle positioner reads 17 in, Hg at best. If vacuum falls much below this, engine stalls. Timing appears correct. If I disconnect Vacuum to
the throttle positioner and block it off, I can adjust idle speed to around 800RPM, but idle seems a little rough.
Submitted: 8 years ago.
Category: VW
Expert:  JacobTD replied 8 years ago.
You have vacuum gage i take it. Please tell me what the needle does... how it moves, and form what to what... close to 750 850 rpm as you can keep it.
Customer: replied 8 years ago.
Should the throttle positioner be connected to the vacuum when I do this?
Expert:  JacobTD replied 8 years ago.
Just actually block everything you can as far as vacuum. If you can do it without unhooking. We are going to test quite alot with this test, mechanicly. Also If you could get first reading... then take rpm to about 2,500 or 3,500 somewhere in there and hold steady.. need to know what gage does.. About 5 sec time
Customer: replied 8 years ago.
at 2500RPM and vacuum blocked, gage reads a very steady 19.
Expert:  JacobTD replied 8 years ago.
what does it read between 750 and 850rpm?
Customer: replied 8 years ago.
Doesn't want to idle much below 850-900. Reading is less than 15, about 14 but very unsteady.
Expert:  JacobTD replied 8 years ago.
things to check then
1 late ignition timing
2 low compression
3 stuck throttle valve
4 leaky carb
5 throttle body or intake manifold leaking

Lets get 5 out of the way. use starting fluid or propain and move around outside of carb, and intake manifolds.. if rpm change then theres your vacuum leak. Might also try an get rid of # XXXXX by advancing or retarding your distributor to see if that changes
Customer: replied 8 years ago.
I tried adjusting timing. I'll have to go and get some starting fluid and get back to you.
Expert:  JacobTD replied 8 years ago.
okay, I spend time in morning, but i will check back every chace i get If you Accept. I havent been paid anything yet for helping you.. and it doesn't cost you anything more
JacobTD and 3 other VW Specialists are ready to help you
Customer: replied 8 years ago.

Leak found around carburetor mount. Local auto parts store did not have new gaskets in stock. Will be available tomorrow. After installation, I will let you know out come.


Expert:  JacobTD replied 8 years ago.
Works everytime
Customer: replied 8 years ago.
New gaskets incorrect size. Bot gasket material and made my own. Engine idling very well after re-insallation. Again, thanx a bunch for sticking with me throughout the analysis and final solution.
Expert:  JacobTD replied 8 years ago.
yep sure deal. Please come back to Just Answer again

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