Vaccuum Secondaries...not opening????

[Grim Reaper]

Originally Posted by skillet

Chevy High Performance March 2004 has a good article on Q-jet entitled "Special Q." It mentioned that "the air-door tension (on the back barrels) must be properly adjusted. If it's too tight, the door won't open under load and the engine will strain. If it's too loose and the door opens too quickly, it will bog. If you feel some light-to-moderate resistance when pushing the door open, the adjustment should be about right." If the front of the carb was facing north, the screw would be at the southeast corner of the carb, corner passenger side as it's mounted. On mine(1969), an allen set screw should be loosened before the other screw is adjusted. I tinkered with mine, but never really noticed much difference. Still learning.

Yep and screwing up that door setting is where Quadra "BOG" moniker came from.

If your pulling steep hills with no Ping or spark knock...They are opening. Leave it hte hell alone.

[Grim Reaper]

Originally Posted by NeCrOmAnCeR

To Paso... When you operate the throttle by hand, you may open the secondaries depending on wether the choke is warmed up (see my previous post) Even if it is opening, the secondary air valve (the plates you see on the top of the carb which lift the secondary metering rods) will remain closed. In your most recent post, the second picture shows the linkage I talked about earlier (holds the secondaries closed until the engine is warm), and in this position it is keeping the secondaries closed. Warm up the engine and check to see if this linkage is swinging out of the way to allow the secondaries to open. I have attached the image with the part circled (hopefully).

Man that is one hobbed together Q-Jet pobably from Micky mouse rebuilders( Holly). It will wor but you have at least two different model carb bolted up there.

Looking at the passenger side picture you have see that red vac plug at the top rear of the carb. That's for a hot air style choke used late 70's till about 81 when they went electric.

The choke atleast is a newer then 81 because it is indeed a electric choke bowl. If it matched the top plate it would have two Vac connections on it and you can easily change a hot air into a electric.

I dont have my book with me but the 2302 is the date code. I think thats 23week of 02=1982 so it could match the choke. THe scary part is that is about the same time mix soloniods came on. Also if you look at the passengerside at the back you can see there use to be a bracket there. Well some years the vac pot for the secondary top door lock out mounted there and the threads look used. They went with the early style because it mounted to the top cover as well.
Base plates were pretty much all the same so no biggie.


Real bastard of a carb ya got. If it works go with it.

[Paso76GMCstepper]

GRIM:

Thanks for the info. I always wondered about that. I have looked at pictures and tech stuff and the parts on my carb never seem to be right. My question is what would be the best way to deal with this problem. Would this carb be less efficient? Should I get a new one or can this one be made right?

Thanks again,

Tony

[skillet]

Are the electric choke Q-jets carbs any better/less complex, etc. than the thermostatic Q-jets?

[Grim Reaper]

Originally Posted by Paso76GMCstepper

GRIM:

Thanks for the info. I always wondered about that. I have looked at pictures and tech stuff and the parts on my carb never seem to be right. My question is what would be the best way to deal with this problem. Would this carb be less efficient? Should I get a new one or can this one be made right?

Thanks again,

Tony

Sounds like it's working. Stick with it till it's not.

[Grim Reaper]

Originally Posted by skillet

Are the electric choke Q-jets carbs any better/less complex, etc. than the thermostatic Q-jets?

Much more consitant with electric choke. You do have to add a oil pressure switch so that if the engine is not running if doesn't get power. That's how GM had it. If you jusnk yarding then any GM with a Quad or a Dual will have the switch if it was made between 81 and 86. It's either behind the distribuotr or above the oil filter. Get the harness as well and fuse it at 15 amps on a IG circuit.

Now pass on the Quads that have the plug on the top of the carb front. THos are a pain.

[screwballl]

that sounds like a similiar problem that i am having with my 76GMC c1500 w/ 350, stock rochester 4bbl carb... when i floor it it doesnt seem to get that extra boost from the secondaries and sometimes bogs... i will have to go through mine and see what i can see and do based on the info here.

edit: ok i got 2 pix, nothing strange on the drivers side, but on the passengers side, the vacuum advance only pushes forward and seems to operate the primary whereas in order for the secondary to open, it turns to the back and the vacuum only travels in one direction (pulls to the front)... theres no other links or vacuum connections connected to the secondary that i have found unless it is internal. it doesnt matter if the engine is warm cold or ignored, the secondary does not seem to have a working link...

[Destructo]

Mine runs pretty good until I get to the secondaries then I have some bogging and it tends to run rich for a little bit. If from a stop I wanna go fast it works better not to floor it instantly, works better if I just open primaries but not secondaries and slowly roll into the seondaries, mine doesn't have the rod to control the plate at the top.

[screwballl]

yeah i have to start with about 1/2 throttle then slowly floor it to get decent acceleration, otherwise it just feels like its holding back....

[SanitysBane]

i don't have the butterfly on for the choke, i have no problems gunning it from a stand still, unless its cold

[screwballl]

ok i took mine for a test drive since last post(s)...
i took the air cleaner off so i could hear the secondary opening up...
i drove it 10 miles or so to pay a bill, several times gunned it from 30-45 mph up to at least 60mph and the secondary would not open up...
shut of truck, ran inside for less than 5 minutes, when i came back out and on my way home, did the exact same thing and several times they opened up with their loud throaty roar, so i decided try something else. Stopped at the gas station to get something to drink and talked with a friend for 10-15 minutes, then drove it back home and they opened up again both times that i gassed it. So they are opening up but it still feels like theres some hesitation at first...

as a side note, on the way home some little tricked out Accord thought he would race me at the front of the pack of cars, they opened up nicely and went from 30mph to 70 in no time while the ricer sounded like he was about to blow somehting trying to keep up with me his loud ass muffler gave it away that his car was wrapped up well past 6k rpm... when he finally caught up with me a few miles down the road he was just looking at my truck with a puzzled look




this is the side he saw for a short while:



it may not be the best looking truck and may not always run the best but for a worn out tired stock 350, he still holds up when i want him to

[Destructo]

I bet you wouldn't be able to keep up with my daily driver, and its all stock. MMM, 1.8L Turbo! My beetle does 0-60 in 7.6 seconds stock, I think that is with an automatic, mine is a 5 spd, pulls a lot harder than my truck ever has hehe.

[screwballl]

maybe not Destructo but for a tired truck he does damn well

[TwinTurbo]

Is that a turbo S 1.8? I thought they only came with a 6 speed manual, no auto available on the turbo. As for the 0-60 time, you sure you're not a second off?? Should be somewhere around 8,5 secs.

[Destructo]

no, mine is a normal turbo 1.8Tm 150HP, 163 torque stock. 0-60 on a stock 1.8T (non s-model) is 7.6 seconds from what I have seen. I have a G-tech so maybe when I get it back from the dealer i'll try it out. It pulls pretty damn hard though.

And VW makes (or did) a normal 1.8 turbo (5 speed), turbo s model (6 speed, 6 speed auto available soon I believe), and of course the wimpy 2.0 N/A model and a Turbo Diesel model. This is in the states anyway, if your in another country I don't know, and I don't know what models are available in 2004 only.

[screwballl]

yes he is in Netherlands, Dest and i have seen cases of low elevation your car getting low sevens

[TwinTurbo]

A 150 hp beetle will not do 0-60 in 7.6

The Netherlands is about the lowest elevatoin you will find anywhere, we're mostly BELOW sealevel and I can assure you it will not do 0-60 in that time

I know someone who has one and my coupe fiat is faster and it's not 8 sec fast