THE CHOKE TAKES ABOUT 2 MINUTES TO OPEN UP

  • Tiny
  • trainmanzz
  • 1984 Oldsmobile 88
  • 225,000 miles

On my 307 4 barrel carb making the engine run rough til it opens up. If I take the air cleaner off so I can observe the choke, The vacuum pull off takes too long to open the choke. About 2 minutes of running the choke suddenly opens up and the engine smooths out. I checked all the vacuum hoses are good and go where they should.

Monday, February 13th, 2012 AT 9:14 PM

13 Answers

  • Tiny
  • Jacobandnickolas
  • Expert
  • 68,410 posts

Are you sure the vacuum pull off is good?

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Monday, February 13th, 2012 AT 9:20 PM
  • Tiny
  • trainmanzz
  • Member

The choke pulloff is good the problem is what controls the pulloff. Maybe the vacuum relay or what signal tells the relay to apply the vacuum to the choke pulloff.

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Tuesday, February 14th, 2012 AT 3:19 PM
  • Tiny
  • Wrenchtech
  • Expert
  • 19,808 posts

I have never seen a choke pull off operated by anything. It connects to direct vacuum at the carb.

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Tuesday, February 14th, 2012 AT 3:40 PM
  • Tiny
  • trainmanzz
  • Member

On this car the vacuum pulloff goes to a vacuum relay that has several vacuum lines and a wire harness going to it. All the lines are connected properly according to the chart under the hood.

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Tuesday, February 14th, 2012 AT 4:36 PM
  • Tiny
  • Wrenchtech
  • Expert
  • 19,808 posts

I don't know what you're looking at but I've rebuilt many a Quadrajet and NEVER has the choke pull off gone anywhere but back to the vacuum supply at the carb. It would defeat the whole reason for having a choke pull off. It's sole purpose is to partially pull the choke open on start up.

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Tuesday, February 14th, 2012 AT 4:44 PM
  • Tiny
  • trainmanzz
  • Member

Wrenchtech, thanks for responding to my choke problem, but in the picture in your reply shows the pulloff in the front on the carb that operates the large butterflys at the rear of the carb, and it is indeed connected right to the carb as shown. The problem is the pulloff at the rear of the carb (not shown in the picture) it operates the smaller butterflys at the front of the carb, which I thought was the choke as it is the ones that are also connected to the thermostatic spring and fast idle cam. When the front butterfly opens the engine smoothes right out. The rear large butterfly does not move. It stays closed.

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Tuesday, February 14th, 2012 AT 5:58 PM
  • Tiny
  • Wrenchtech
  • Expert
  • 19,808 posts

You are obviously not familiar with Quadrajet carbs. There is only one choke plate on that car. What you're referring to are the vacuum secondaries.

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Tuesday, February 14th, 2012 AT 6:06 PM
  • Tiny
  • trainmanzz
  • Member

Whenchtech, The pulloff in the picture is the one that operates the vacuum secondaries. I am having trouble with the other pulloff that is not shown in the picture that operates the choke. I am sure I am looking at the choke as the secondaries are much larger than the choke. The hose on this pulloff goes to a solenoid assembly that has 6 vacuum lines and a wire harness going to it.

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Tuesday, February 14th, 2012 AT 6:22 PM
  • Tiny
  • Wrenchtech
  • Expert
  • 19,808 posts

You're wrong but I'll let someone else tell you that.

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Tuesday, February 14th, 2012 AT 7:00 PM
  • Tiny
  • trainmanzz
  • Member

Whenchtech, I'm sure your knowledge of quadrajets way exceeds mine. I'm not trying to make this a battle of who is right or who is wrong.I just thought I would try to get some help with a problem with my car. I just tried to explain as clearly as I could what I was seeing on my car. I move the pulloffs with my finger, I can see what each one does. On my car, the one shown in the picture when pulled would prevent the vacuum secondaries from opening. And the other pulloff when pulled opens the choke part way and when it does, the engine smoothes out and runs good. This is from a cold start. The whole time the vacuum secondaries stay closed. I think this choke should open a lot sooner.I wish I knew what is wrong. Where am I going wrong? Could you or someone please tell me where my mistake is? Is something different with my car? I sure looks all factory and un-screwed with, very clean and well maintained.

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Tuesday, February 14th, 2012 AT 7:30 PM

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