Don't think secondaries are opening

[HighDesert-T]

Don't think the secondaries are opening on the carb. When you put your foot in it, it stumbles then kicks in. Doesn't have that sucking the world sound in that I remember from back in the day of the 4 barrell carbs. Is there anyway that I can test these things?

Thanks.

 

[fc227]

On those Q-jet's , make sure the choke is opening all the way. Because there is a lock that prevents the secondarys from opening if the choke is closed.

 

[HighDesert-T]

How do you check that? Take off the cover, wait till it is warm and kick the throttle linkage to see? Can the choke unit be replaced if it is not working?

Thanks.

 

[fc227]

Let the car run until warmed up. Shut the car off. Remove the carb hat and see if the choke is full open.

 

[fc227]

Also check to see if you have 12 volts to the electric choke housing (single wire) with the ignition on. If you do have 12 Volts there and the choke is not opening or moving at all from when it was cold. The electric choke housing could be open and Yes it can be replaced.

 

[Ttype83]

Most chokes do not go bad, just need setting.
On the passenger side (same as choke) behind the choke at the bottom is a small lever that connects to a rod on the secondaries when cold. Or it can bind not leting the secondaries open.
This lever can be removed, but you have to remove the choke.
THT
Jim

 

[HighDesert-T]

Was out looking at this last night, didn't check for the voltage, will do that tonight but this is what I found.

After pushing the throttle linkage back a few time the secondaries did open. WOW, did the engine come to life. Did this a few times and it "seemed" the secondaries were working. Took the car for a test drive and the secondaries were not opening.

Could the linkage be misadjusted from the gas pedal?

I will check these other things tonight.

Thanks for the assist.

 

[b4black]

I'm copying most of this from another thread:

With the car cold, work the throttle. You should see the seconadry linkage move. There is a "pointer" that should go from 12 o'clock to 3 o'clock. If not, check your throttle* and trans* cables.

Look at the end of the shaft for a slot wrapped by a spring. The slot won't move because there is a lever and the other side stopping it. With the engine hot, or by moving the fast idel cam, the lever will be out of the way and then the shaft is free to move with the linkage. If not, check the spring*.

The air valves (upper butterflies) open by vacuum. Make sure they are not binding*.

*I have been bitten by all of the above.


GET A PRESSURE GAUGE and connect it to boost pressure. You will know right away if your seconadires are opening or not. 6 psi is max on the primaries only.


The seconadries don't even begin to open until 90% throttle movement. Your bog is probably something else. It's likely it's not even the carb itself. Do you have a vacuum line diagram?

 

[HighDesert-T]

Thanks guys for all the help. What it turned out to be was the fuel filter being clogged. Little ol' ladies maybe sweet but... It was filthy in there, just as bad as the airfilters. Couldn't find a PCV tonight but I imagine that needs to be changed as well.

Once the filter was changed it was time for a test drive, she went to red once for me but not again since. Didn't have the filter tight so there was a fuel issue. Got that fixed and took her out again. No yellow or red indication but you could hear the turbo spool. Also, the temp climbed like crazy. Guess it is time to flush it, check the radiator and put in this new thermostat. All will have to wait. Leaving town soon and have a class this weekend. On the brightside, it idles smoother and shifts a lot better with it getting gas and the secondaries open. You can tell it has been a long, long, long time since those bad boys have been exercised.

Thanks again for the assists.

 

[Ttype83]

hehehe good luck finding the PVC...Hope you have small hands.

At the back of the carb, bottom center is a vac hose (3/8" I think)
follow the hose to the passenger side, almost under the back of the turbo. It can be replaced with out removing any thing, but I suggest that you remove the carb to save your knuckles.
While you have the carb off, replace the compressure line going to the wastegate

LET the car idle for at least 2 mins to cool down the turbo before shuting down.....

 

[b4black]

I would be real surprised if your secondaries were opening and you were only seeing ~5 psi max (about were the red light comes on). You should be able to light the red one only using the primaries. You have a restriction somewhere, or your lights are off.

Again, you need a pressure gauge. If your really at 5-6 psi max, when you get to 9, your face will look like this

 

[HighDesert-T]

Well this thing wouldn't stay running this morning so I had to use alternate transportation.

Here is the latest. The Vac hose that runs under the turbo is dry rotted and off. This may be the cause of most of my problems. I could hear the turbo spooling but wasn't getting any boost indications. Also it sounded as though there was an awful vac leak. So the Turbo will have to come off, fix that line, replace the PCV and whatever else I can find under that needs to be done. Gonna have to keep a lot of VAC line around.

Looking forward to that 9 psi!

 

[b4black]

That leak under boost is air and FUEL.

Don't take the turbo off. It's not a simple job. I replaced that line with the turbo on. It's not easy, but can be done. Take the carb and actuator off. Then use a coat hanger to thread the hose under the turbo.

The boost line T's twice. That gives three "legs". One to the actuator, one to the MAP sensor and one to the boost light's switch.

The other line on the actuator is for vacuum. It isn't needed and the vacuum side of the actuator usually leaks, so cap it off. While you have the actuator off, apply pressure to it a make sure the rod comes out.

 

[HighDesert-T]

Thanks for the tip. Just a tight fit in there. Guess it is easier with the carb out of the way and all those vac lines.