Q-Jet part throttle lean condition

Discussion in 'The Venerable Q-Jet' started by buick64203, Sep 24, 2017.

  1. Daves69

    Daves69 Too many cars too work on

    Where did you get your kit? I have been thinking about this for a while and have a couple of vehicles that need some fine tuning.
  2. buick64203

    buick64203 Just plum crazy Staff Member

    I got it off Ebay. The basic kit was like $220 and came with an 8 foot cable and a weld in bung. I had to buy the 18 foot cable and the tailpipe adapter separately. The standard 8 foot cable wouldn't reach from the tailpipe to my front seat
  3. Daves69

    Daves69 Too many cars too work on

  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Jason, see if the power piston is staying down at idle. Put a screw driver down the vent with the engine off. See if you can feel the piston go down, then spring back up. Then start the engine and put that same screw driver on top of the piston. Wing the throttle quickly and see if the screw driver pops up.

  5. buick64203

    buick64203 Just plum crazy Staff Member

    Dave, this is the tailpipe clamp. Innovate Motorsports #3728


    And this is the meter kit I bought-


    And the 18 foot cable-


    Its gets a little pricey but this way it becomes a tool in your toolbox and can be put on any car your working on

    Yep, did that one both carbs.
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Are you sure the jetting is stock? Could someone have messed with it before you?
  7. buick64203

    buick64203 Just plum crazy Staff Member

    Who the hell knows. I don't even remember how the Riviera wound up with a Stage 1 carb on it. I didn't know I had one. I have to open it up and find out
    techg8 likes this.
  8. buick64203

    buick64203 Just plum crazy Staff Member

    Ok, more results...

    Seems to idle now at 14.2-14-5. Pretty sure I can richen that up a little. Cruise seems to be about 12.9. So assuming the stock jets are in there, what rods do I install?
  9. wkillgs

    wkillgs Gold Level Contributor

    You need to check the ratio at WOT before thinking about changing rods.
  10. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You need to verify the jetting is stock. Who knows what is in there.
  11. johnriv67

    johnriv67 Well-Known Member

    How did this end up? I'm about to turn in a similar direction based on my carb and my need to tinker with things until perfection.
  12. buick64203

    buick64203 Just plum crazy Staff Member

    Still haven't gotten around to it. Too many projects dividing my time. The carb in question is still sitting on the 430 in my Riv. And that car has been laying dormant since last year. Im getting around to getting that out of storage and back on its legs. Then trying to get that carb finally sorted out
  13. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    what rearends do you have in your Rivieras. ?
  14. johnriv67

    johnriv67 Well-Known Member

    3.42 posi. Not sure about Jason's
  15. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Dam why does my GS have to have a 3.07 one legger. Probably never thought they would tow something. I would like to have a 3.07 posi.
  16. buick64203

    buick64203 Just plum crazy Staff Member

    I got back into this today but it didn't go quite as planned. As it stands now, the 71 Stage 1 Q-Jet is on it and runs pretty darn well. The "problem" carb is still on the Riv....

    The car always felt a little sluggy even with a set of 3.42s out back. Never really looked into it that much because I don't race it. It goes to the store, Home Depot and some cruise nights. So first thing this morning, I start looking into its "slugginess".

    First thing I check is to make sure the carb is opening up fully when the gas pedal is matted. I throw Jen behind the wheel and have her floor it. I look down the secondaries and guess what! The secondary throttle plates are barely cracked open!! Ive been running it essentially as a 2 barrel. I take my needle noses and bend the little tang on the linkage and adjust it so the secondary throttle blades are nearly vertical. Cool! Now that's gonna make a big difference! Now Im all hopped up to test drive it. I go to start it and nothing...just cranks and cranks and cranks!! Arrrgh!!

    I clearly have no fire. Checked for spark- nothing. WTF?? The car was just used Weds and drove to its spot in the driveway. No symptoms whatsoever last time out. My first feeling was the Pertronix took a dump on me. I didn't know of a valid test procedure other than just putting the points back in, so.... Luckily, all the ignition parts I took out I put back in the Pertronix box in the glove box. I whip out the Pertronix and re-install the points. Adjust up the points and go to start it......nothing!!! Now Im starting to freak out.

    I go back to square one and start trouble shooting. I diagnose it as a bad coil. I steal the coil out of Jen's 73 Mustang which is a Crane PS-20 Flamethrower. I throw Jen's coil in and VROOOOM!! Starts on half a crank. Sonofab....How the heck does a coil just "go bad" sitting in the driveway for 3 days? It has been raining for 2 of them though. Maybe the rain got to it? Who knows. Its an original Delco Remy so its as old as the car.

    Anyway, so now we have a working ignition system. Onward I say. Might as well leave the points in for now. I set the dwell and adjust the timing to 10 degrees initial. Warm it up and go to take it for a ride. Running good. Row through the gears nice and smooth. I take off from a light and lace into it. As soon as the secondaries start to open, the car falls on its face. It feels almost exactly like I hit a rev limiter. Its like its got a bad set of wires on it. What now????. So lets think this through logically- the only real change is the removal of the Pertronix which was probably not the issue in the first place. So back in goes the Pertronix. Starts up with the Pertronix back in so that works. I make sure the timing is still on the money and go for another test drive. I give it a little gas and the stumble is gone. I get it into first and whack it! Front end comes way up and the little G70's nearly rip off the wheels!! The tires go up in smoke, the car is drifting sideways and the 455 is quickly roaring up to 5k rpm! Time to shift into second as the car is still sideways. Tires never got any traction and were still baking themselves when I let off. Holy crap what a difference!! Its like a put a different engine in the damn thing. So happy :)

    Whew...Now that its all straightened back out, I'll put the "240" carb back on it next week and try and figure out that riddle
    Last edited: May 20, 2018
  17. Taulbee2277

    Taulbee2277 Silver Level contributor

    Isn't troubleshooting fun :) Nice work getting the car back on the road, now just have to put a coil on the mustang before she finds out.
  18. buick64203

    buick64203 Just plum crazy Staff Member

    Thankfully my big block bruiser is fixed otherwise I wouldn't have anything to go to the grocery store in. :D:D

  19. buick64203

    buick64203 Just plum crazy Staff Member

    It can probably sit there with no coil on it for 6 months and she wouldn't know. That's how much she drives it. But now that I said that, she'll want to take it out this week!
  20. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    To quote Han Solo, “ Women always figure out the truth, always “:D
    Last edited: May 21, 2018
    Brett Slater likes this.

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