New member/620 build.

[RyanC]

If you search on you tube for weber tips.and tricks there is a south African bloke who goes through the different parts.   

 

Also Mazda mitch has a great initial tuning video.

 

I mean usual things spark okay?

Fuel pump pumping?

Fuel bowl getting fuel.

 

Maybe pulling and checking fuel jets for all of them.  Does the accelerator pump squirter. 

 

 

Does it start splutter and die or just won't start.

[Bas90501]

7 hours ago, RyanC said:

If you search on you tube for weber tips.and tricks there is a south African bloke who goes through the different parts.   

 

Also Mazda mitch has a great initial tuning video.

 

I mean usual things spark okay?

Fuel pump pumping?

Fuel bowl getting fuel.

 

Maybe pulling and checking fuel jets for all of them.  Does the accelerator pump squirter. 

 

 

Does it start splutter and die or just won't start.

I’ve searched YouTube. A lot of the videos require the car running lol. 
 

fuel is pumping. Fuel bowl seems to be getting fuel. The jets should be okay. It’s a brand new carb. It indeed squirts fuel. 
 

it starts sputters then dies. At best I’ll have a rough idle for about 1-2 minutes. 

[Stoffregen Motorsports]

Check your fuel lines and filter. Maybe even the pump. It could be filling up the bowl for initial start, but then running out of volume when you try to drive.

[RyanC]

9 hours ago, Bas90501 said:

I’ve searched YouTube. A lot of the videos require the car running lol. 
 

fuel is pumping. Fuel bowl seems to be getting fuel. The jets should be okay. It’s a brand new carb. It indeed squirts fuel. 
 

it starts sputters then dies. At best I’ll have a rough idle for about 1-2 minutes. 

Have you set the idel mixture screw at between 1.5 to 2 turns out? Tried increasing idle?

 

What I have learned is that these things have a jet for each stage so checking idle jets might be a start.

 

Are you using choke?

If you pull the pump outlet hose of the carb and put it in a bottle is it a solid squirt of fuel. 

 

Seems like fuel if it was running before but all the plugs, plug wires etc all okay?

 

This is the channel I was thinking off.

 

 

 

Edited September 5, 2022 by RyanC

[datzenmike]

19 hours ago, Bas90501 said:

The hose from the dizzy goes into carb. 

 

 

But here the vacuum advance hose is shown connected to a metal line....

 

 

[Bas90501]

So the red is the hose connected from dizzy to carb. 
 

yellow isn’t connected to anything lol. 

[Bas90501]

1 hour ago, RyanC said:

Have you set the idel mixture screw at between 1.5 to 2 turns out? Tried increasing idle?

 

What I have learned is that these things have a jet for each stage so checking idle jets might be a start.

 

Are you using choke?

If you pull the pump outlet hose of the carb and put it in a bottle is it a solid squirt of fuel. 

 

Seems like fuel if it was running before but all the plugs, plug wires etc all okay?

 

This is the channel I was thinking off.

 

 

 

I have tried setting it 1.5-2 turns. But still can’t get it to run correctly or run at all for that matter. 

 

I did in fact get it to accelerate and even drove it around the block with good power. It seemed I had fixed it. But once it got cold it started to have trouble the same issues. Wouldn’t idle or choke when I tried to accelerate. 
 

im a noob and don’t understand your question am I using choke. I have the electric choke version. The choke seems to work fine. Butterflies are closed when cold and start to gradually open once the engine warms a up. 
 

plugs and wires seem to be okay. They’re new. 
 

thanks for the video. I’ll check it out. 

[RyanC]

No worries I'm still running the manual and need to fine tune the idle etc.

 

What happens if you disconnect those vacuum / or not vacuume 😛 hoses?

 

Pretty sure I only have the vacuum for the dizzy, water bypass to inlet manifold hoses and rocker to air filter hoses on mine.

 

Nothings loose, dizzy etc 

[datzenmike]

1 hour ago, Bas90501 said:

So the red is the hose connected from dizzy to carb. 
 

yellow isn’t connected to anything lol. 

 

Correct, I see it now.

[Bas90501]

34 minutes ago, datzenmike said:

 

Correct, I see it now.

Does everything seem connected correctly? From what you can see? 

[datzenmike]

Seems ok.

 

I see an EGR block off plate. Make sure there is no possibility of a vacuum leak there. Check the entire intake for any chance that a vacuum hose has fallen off or wasn't connected. Look at the hose to the brake booster for damage/cracks. The fitting on the intake often has a tiny fitting for a vacuum signal to the automatic transmission. Yours may have one and it should be capped. Look at the Weber adapter, does it have good gaskets and are the carburetor bolts snug. A good strong idle demands a high intake vacuum.

 

Disc brake trucks have electronic ignition. Unknown what this is, maybe body was swapped. Pop the distributor cap off and look... does it have points??? A '75 should. If it does, bump the starter until the points are on the highest point on the cam lobe and fully open. The points gap should be 0.018"-0.022". Timing should be 12 degrees BTDC. As idle provides very little air and fuel all engines in this condition want more advance than they get. I would run the 12 degrees for strongest idle.

 

Valve lash. If one or more valves are tight it can upset cylinder filling and if an intake can leak intake vacuum, and you want a strong vacuum signal at the carburetor. Preferably set with engine hot but easier to check/set when cold. Check that they are 0.008" intake and 0.010" exhaust when cold. What were are looking for is a valve with no lash at all. 

 

 

Carburetor:

Have you tried turning the idle speed screw up?

 

I assume that the Weber engages a fast idle circuit when the choke is on????  I don't know Webers much. ANYONE??? If it has a fast idle, then the engine should rev up higher once started. Yours does not.

 

What happens if you use the throttle to keep the engine revved up?

 

Are the choke plates fully closed when starting? The should open slightly once started. Too rich a choke setting is as bad as too lean when starting.

[RyanC]

Fast idle adjustment in depth on the electric choke by Mazda Mitch.  

 

 

[datzenmike]

Learned something about the 32/36.

 

Fast idle on any carburetor not only prevents stalling, because the idle is stronger, but it also speeds the warm up. Generally 1,800 to 2,200 RPMs on a stock Hitachi. No need to kick the fast idle down to drive a standard, just drive away. There is a kick down function to reduce the choke but only for necessary performance when engine is cold. 'Kicking the idle down' too soon during the warm up only causes the idle to become poor. Driving will move the idle cam as it warms up and the idle comes down by itself, again on a stock Hitachi. 32/36 would be similar.

[RyanC]

I would also be checking for damage on idle mixture screw easily damaged if over tightened and pulling the idle jets and checking what size they are.

 

Once you open the throttle you begin to use the emulsion tubes basically as throttle opens it enables vacuum to draw not just idles jets but then through the emulsion tubes more and more.