Author Topic: Help with a Q jet  (Read 5262 times)

Offline raguza123

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Help with a Q jet
« on: June 11, 2013, 11:16:53 AM »
I have a Q jet # 17080260 I ordered all the parts from Cliffs to rebuild.
Jets #68, Primary Rods #39, Secondary rods #DA,  idle mixtures, all air bleeds,  idle tubes and of course a rebuild kit with everything to repair it.
I had called Cliffs to order this and I assume when he asked about the engine size a 326 close to stock that everything was sized for this?
Now I finally got around to rebuilding her and I been trying to get it to run, The electric choke works and goes on high idle and she'll run and smoothly, get her down to around 1300rpm's and then drop it to idle and she stalls, then it won't start unless I pump the gas once and she'll run then stall, if I put high idle on she'll kick over and run once I come off high idle I need to close the choke butterfly a little then she'll run at idle if I open it she'll stall.
I am lost, does anyone have an idea what is wrong?

Offline Shark Racer

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Re: Help with a Q jet
« Reply #1 on: June 11, 2013, 11:19:40 AM »
Sounds like your idle mixture is too lean, judging from the fact that it'll run with the choke flap closed a bit. How far out are you on the screws? I'd give each screw ~half a turn to see where that gets you.

Offline raguza123

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Re: Help with a Q jet
« Reply #2 on: June 11, 2013, 11:22:06 AM »
I was told to start at 5 full turns out?
I was at 2 full turns

Offline raguza123

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Re: Help with a Q jet
« Reply #3 on: June 11, 2013, 03:53:11 PM »
I don't seem to get it to run even 5 turns out, only at high idle or as I said when I drop to idle I need to close the choke plate a little.

Offline Shark Racer

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Re: Help with a Q jet
« Reply #4 on: June 11, 2013, 05:24:39 PM »
Have you verified there aren't any vacuum leaks anywhere? When you do get it to idle, where is it at idling at RPM wise?

Offline raguza123

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Re: Help with a Q jet
« Reply #5 on: June 11, 2013, 06:06:50 PM »
I can get it to high idle around 1500rpm's but when I bring it down to a normal idle 750rpm's it will stall unless I close the choke plate a little.

Offline raguza123

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Re: Help with a Q jet
« Reply #6 on: June 12, 2013, 07:39:09 AM »
I found this morning that when I did the throttle bushings, I never lubed them in any form, I was reading about how the pump spring should close the primaries, well mine wouldn't close at all, I lubed them with WD and it closes now on the pump spring and my secondarie's were hanging a little , now they close.
Are the secondaries out of adjustment? and they could be the issue?

Offline raguza123

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Re: Help with a Q jet
« Reply #7 on: June 12, 2013, 04:06:46 PM »
I cleaned the shafts out with carb cleaner and put some drops of oil and worked it in.
I got her to start and run at high idle and then kicked it down and she stayed running.
started with the idle mixtures at 5 full turns out, drove them in all the way and backed them out to 4 turns out
it didn't affect the idle or try and stall, and at 4 turns it smells rich and burns my eyes.
APT screw is at 3 turns up, but she's idling, I am getting a slight pop out of the exhaust, means my mixtures screws are set wrong?

Offline raguza123

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Re: Help with a Q jet
« Reply #8 on: June 13, 2013, 03:46:04 PM »
I been told I should have gone with a earlier Q jet, because this one is emissions calibrated and is lean because it's an EGR carb.

Offline Ethan1

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Re: Help with a Q jet
« Reply #9 on: June 13, 2013, 05:17:15 PM »
I been told I should have gone with a earlier Q jet, because this one is emissions calibrated and is lean because it's an EGR carb.

 The later carbs are better in general. If you're looking to keep it stock, then an eariler carb with Cliff's kit/parts might be best. :D
Ethan

1972 Chevelle

(oo______oo)

Offline raguza123

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Re: Help with a Q jet
« Reply #10 on: June 13, 2013, 07:55:15 PM »
it doesn't matter to me she's not close to stock(the Car), I read Cliff's book and he does recommend the Q jets after 1975, that's why I went with this one, I know it has some issues with the throttle plate, we believe it's opening up.

I do have a earlier one, a 1973 Pontiac 455 carb. but I wouldn't know how to get it to run on my engine.

Offline 429bbf

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Re: Help with a Q jet
« Reply #11 on: June 14, 2013, 05:45:26 AM »
sounds like you getting it figured out . your secondaires being open a little was causing a huge vacumn leak thats why it wouldnt idle. do you have a little clearance on your linkage between your pri and sec? also the popping is usually caused by ignition timing or cam failure.can you supply a little more info .timing , vacumn. etc.

Offline raguza123

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Re: Help with a Q jet
« Reply #12 on: June 14, 2013, 06:47:39 AM »
I know it's not the cam, cam is new and broken in correctly and running ZDDP in the oil as an additive.
Timing could be an issue, I did notice when I connected the vac. adv. up to the full vac. port the idle didn't jump up like it should, it came up a little bit.
I need to put a vac. gauge on her, I believe something is leaking.