Q-Jet Choke housing re-install keeps binding up?

[da_raabi]

I just finished up rebuilding the quadrajet on the truck. This is my second rebuild of a qjet, so I've been in these things before. Before the rebuild, the carb ran fine and the choke was 100%, I only decided to rebuild with ethanol-friendly parts so I could run cheaper gas (70 cents/gal extra for E-0 was killing me).

Anyway, the rebuild went fine, and once running the truck runs like a raped ape. Seriously, this thing has never been so peppy. But for the life of me I cannot seem to get the choke housing re-installed correctly. Every time I bolt it up and get the shaft through the choke arm lever (the PITA part down in the carb itself), everything gets bound up and stuck. I had zero problems with this on my last rebuild. What could I be doing wrong?

I've been struggling to find any pics or info on the correct installation procedure of all the choke parts, and have been simply working off my other known-good carb. The two levers attached to the choke shaft appear to be installed correctly, but the inner-most one that attaches to the splined area of the shaft keeps falling off the splines. Is there a correct orientation for that arm vs. the shaft?

What am I doing so wrong?

 

[fussfeld]

Is the carb original to the truck or engine, or is it a remanned atrocity?

 

[yevgenievich]

There are a bunch of levers on choke side and they all have to line up. Do you have a picture of how it is currently?

 

[Charlie]

If you haven't checked youtube yet, I have seen several on qjets and watched many for my own issues at different times.

 

[da_raabi]

Well I looked on youtube and found some good shots of the choke shaft to lever orientation. It looks as though it should be set up so that the choke arm lever (the PITA one that goes inside the carb that engages the shaft) should be pointed to around the 1-2 o'clock position when installed. I had it at the 3 o'clock position, which was preventing the arm from rotating downward to open the choke plate. The choke seems to work okay now, barring some fine-tuning adjustments.

Now my problem is that the fast idle does now want to come down. It will if I pop the throttle under the hood, but not if I gun it with the pedal.

I also get heavy ping under load regardless of timing or fuel grade (87 or 89 with ethanol).

I am seriously getting a bad case of the "quadrajet blues".

 

[yevgenievich]

Last time I bought a kit for qjet from cliff , there were couple of pages of what pieces to bend to adjust things. Upon application, all of the various linkage rods might need individual adjustment to archieved proper operation.
Mine still has fast idle sometimes not working, but I have not looked in to it yet

 

[da_raabi]

Well I took the carb back off the truck last night. I've got a set of 74 jets on the way to up-size from the 73s. I'm hoping that might help with my pinging issue.

I also took another look at the choke arms/linkages. Everything I am seeing tells me that it should all be working correctly. No idea why the fast idle is getting stuck when installed.

With my finger acting as the choke spring (I took the electric element off for testing), when I rotate the throttle, both choke arms rotate upward, the choke plate closes, and the fast idle engages on its highest cam when I release the throttle. This should be in the cold running configuration.

Allowing my finger to pull a little choke off, the choke plate begins to open, and if I rotate the throttle again, the fast idle cam drops to the next flat, allowing the idle throttle to decrease slightly.

Allowing my finger to fully rotate the choke allows the choke plate to open completely and disengages the fast cam entirely while simultaneously allowing the secondaries to open. The throttle can now sit all the way down on its stop screw. This should be the full-hot running configuration.

This appears to be the correct operation, right?

 

[DoubleDingo]

That appears to be correct for the choke operation. Baffling why it doesn't drop with the throttle. Mine will hang up too, I really have to gun it to let the rpms get up around 4k. At least it sounds that high.

Glad you got the choke arm inside figured out. I was going to chime in but I didn't have anything to suggest. I now know to keep an eye on the orientation when I rebuild mine.

 

[da_raabi]

That appears to be correct for the choke operation. Baffling why it doesn't drop with the throttle. Mine will hang up too, I really have to gun it to let the rpms get up around 4k. At least it sounds that high.

Glad you got the choke arm inside figured out. I was going to chime in but I didn't have anything to suggest. I now know to keep an eye on the orientation when I rebuild mine.

Yeah I didn't even think about it the first time. When I rebuilt the quad on my Camaro I did not have any of these problems. The splined arm did not fall of the shaft on that one though, so the orientation/alignment was easy. On this one I actually had to put a very thin washer between the lever and the carb body to keep it from falling off the splines again.

My first carb rebuild was a piece of cake, for some reason this one is just kicking my butt!!!

 

[da_raabi]

Ok I'm back. Finally got the truck running right. I had a whole bunch of problems. Ended up buying a new rebuild kit from Cliff Ruggles - what a difference.

First, the needle and seat that came in the first kit were too small. I actually measured this with numbered drill bits and found that the "new" seat was 1-2 sizes smaller than the original seat I pulled out. Cliff's kit contained a seat of the same size as the original.

Second, the secondary cam was broken. Replaced it as part of the kit.

Replaced the choke shaft and adjusted the high-speed idle.

Installed the fatter main jets.

Adjusted the timing while running on the 87 ethanol fuel.

At this point I've just got a little ping in when I get into the secondaries. I'm going to try fattening up the rods and see if that helps. Otherwise this truck runs better than it ever has. It starts easy (still needs a tiny bit of choke adjustment though) and idles/accelerates awesome.

I can tell you... I'm already loving the 70 cents per gallon savings of going with 87 octane E-10 over the 89 Octane E-0. Haven't noticed any performance drop either.

I'll post up results after I get the new rods installed.

I think I finally beat the quadrajet blues!!!

 

[Christian Nelson]

Looks like you got is squared away..

I was going to mention to check, I used to see this every so often back in the day.

Sometimes people overtighten the wingnut on the air cleaner, and this warps the throat of the carb slightly enough to make the choke butterflies catch on the edge of the housing and not release when they should.

I found that a bit of a tap or two with a deadblow mallet on the top of the carb fixed it.

Again, looks like you fixed your particular issue, but I have seen this a few times, and thought it worthwhile to share.

 

[da_raabi]

Looks like you got is squared away..

I was going to mention to check, I used to see this every so often back in the day.

Sometimes people overtighten the wingnut on the air cleaner, and this warps the throat of the carb slightly enough to make the choke butterflies catch on the edge of the housing and not release when they should.

I found that a bit of a tap or two with a deadblow mallet on the top of the carb fixed it.

Again, looks like you fixed your particular issue, but I have seen this a few times, and thought it worthwhile to share.

Interesting. I was not aware of this. I'll make sure I don't go hurkin on the wingnut then.

...which sounds like a candidate from the GMSB quotes thread...

 

[da_raabi]

So I had a bit of a relapse for a bit. Suddenly the truck started running like crap again, but after scratching the ol nugget and the old meat and two vedge I realized I made a whoopsie.

I forgot to tighten down the distributor.

So I re-timed the engine and dropped in the smaller secondary rods and TA-DA!!!!

She runs like a... well you can fill in the blank. She runs good! No more knock!

 

[Rusty Nail]

Let it soak in Diet Coke overnight..

 

[da_raabi]

Let it soak in Diet Coke overnight..

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