high idle problems

[Jonatsun]

Ok so before the idle was high ~1300 rpms, so i turned it down to 700 it died, had to look at distributor for timing and one thing led to the next had to reset the timing because guy who did it before was off. 

 

Timing is proper now and hitachi carb is having problems so i scrap it for a weber, and now i cant get the rpms below 2000.

im having a rough time figuring out what wrong its time to ask for help.

[metalmonkey47]

Pull your air cleaner off and check a few things.... 

 

 

1: is the choke open or closed? If closed, the idle will be quite high. Check to see you have 12V at the choke heater...unless it's a manual choke Weber. 

2: Are the throttle plates closing all the way at idle? Perhaps something is binding in the throttle cable/linkage and holding the throttle open. 

[banzai510(hainz)]

HRH lives in Spokane he can help.

 

I always buy a 5A weber as its a manual choke (simple)

 

if Hitachi was able to idle at 700 it was most lkiley good and accle pump worked

[datzenmike]

Ok so before the idle was high ~1300 rpms, so i turned it down to 700 it died, had to look at distributor for timing and one thing led to the next had to reset the timing because guy who did it before was off. 

 

Timing is proper now and hitachi carb is having problems so i scrap it for a weber, and now i cant get the rpms below 2000.

 

im having a rough time figuring out what wrong its time to ask for help.

 

Only thing relevant is the weber.

 

So is it a new $280 Redline or some unknown POS from E Bay?

 

Is it a 32/36 or 38/38 weber?

 

Does it have an idle cut solenoid?

Does it have an electric choke?

 

 

And what did you set the timing at? and did you set it with the idle fast????

[Jonatsun]

the truck is a 79 620 with an L20b

 

weber carb is a 32/36 DGEV from weber carbs direct.com

 

yes idle cut off solenoid and electric choke.

 

the timing is set to stock 44 pin count between punch marks on cam sprocket and crank sprocket. the dizzy is proper also.

 

 

its something simple i just cant figure it out, ive tuned tons of different carbs in my life its something more than just choke and idle screws.

[Jonatsun]

i found a vaccum leak and my pedal seems weak could either of these be a factor?

 

 

[datzenmike]

the timing is set to stock

 

 

But what did you set it to? Was the idle fast when you did? If above proper idle the mechanical and vacuum advance will throw it off.

 

 

Is the throttle cable too tight and not letting the carb close down to idle?

 

Is the idle screw turned down?

 

Is the choke on partly and the fast idle cam engaged?

 

Are the throttle plates stock slightly open?

[datzenmike]

i found a vaccum leak and my pedal seems weak could either of these be a factor?

 

 

 

A vacuum leak usually forces a lean the idle air fuel mixture and lowers the idle speed. If you have a leak, it shouldn't be there so seal it up.