Author Topic: Finally Idlin'  (Read 2202 times)

Offline Snag

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Finally Idlin'
« on: August 20, 2022, 05:56:40 PM »
  I posted some time ago about the work I'm doing on my '86 GMC 1500 pickup (305 "H" motor/700R4) .
 Background : I loaned my son my truck , and he f***ed it up . Blew a trans because he couldn't be bothered to check the oil . Damaged an oil pressure sensor while replacing the trans . Sensor dumps all the oil resulting in a near-seizure of the motor .
  Now : The motor has been bored .060 over , flat top pistons for ~9.7:1 compression . Elgin E922P cam (.443/214°@ .050 int , .466/224° @ .050) with an Edelbrock Performer on top and a set of small/long tube headers . There's a 600 Holley vac secondary settin' on top of it all ... and I've been a quadrajet man all my life . It's been a learning curve , I've been fighting idle problems , ended up with a 3/32" hole in the primary throttle valves and opened the secondaries up so the tiniest bit of the transition slot is showing . Finally , a stable idle , and now I can move on the the tach install and other interior/under-dash repairs . And then on to the rear axle ... replacing the stock 2.73's with a set of 3.42's . Had the correct speedo gears installed when the trans was rebuilt  .

Offline VileZambonie

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Re: Finally Idlin'
« Reply #1 on: August 20, 2022, 07:57:33 PM »
Curious why being a Q-jet man you'd waste your time with a Holley 600?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Snag

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Re: Finally Idlin'
« Reply #2 on: August 20, 2022, 08:18:29 PM »
  Mostly because for the first time ever , I couldn't get the dang thing to run right . That stock Q-jet has had problems since the day I drove the truck home some 17 years ago . And I don't consider a learning experience to be a waste of time ... This Holley is way less complicated than the Q is , no vacuum pull-offs , accel pump solenoids , just way less "stuff" to adjust . And now that I've got the idle problems solved , the off-idle response is pretty impressive - don't toe the pedal too hard on a gravel road ! And I suspect it'll be even more lively one I get the gear set swapped .

Offline Jimbo302

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Re: Finally Idlin'
« Reply #3 on: December 18, 2022, 07:03:16 PM »
Almost every qjet I've pulled got replaced with a Holley.  No shame.

Offline Rapid Roy

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Re: Finally Idlin'
« Reply #4 on: December 18, 2022, 09:30:59 PM »
There is nothing wrong with a Q-jet carb. If it is rebuilt by an experienced person, it is a good choice! IMO.
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice