Misfiring on two cylinders
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Joined: Jan 2020
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My mistake it is definitely a dual plane it’s an Edelbrock Performer not a torquer. Took it for a drive and all seems good, temps on the headers are still fairly even and I haven’t adjusted the carb as yet but it’s firing well on all 8
Race Director
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Does your original 79 Quadrajet have a large vacuum port under the fuel inlet on the base of the carburetor?
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Joined: Jan 2020
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Yes there is a large vacuum port where you say as well as one at the back. I used to run a holley but had issues so swapped back to the quadrajet, however, I had also removed all they air pump assembly and various other bits and so not remembering or knowing I plugged the front port, connected the brake booster to the rear port and connected the PCV to the take off on the runner along with the vacuum for the lights etc. as I say I maybe made a school boy error and should have connected the PCV to the front port. Currently running no PCV and all fine but will get some more hose and connect to the front port to see if it still runs fine before getting another PCV.
Race Director
Joined: May 2006
Posts: 18,755
Likes: 2,589
Yes there is a large vacuum port where you say as well as one at the back. I used to run a holley but had issues so swapped back to the quadrajet, however, I had also removed all they air pump assembly and various other bits and so not remembering or knowing I plugged the front port, connected the brake booster to the rear port and connected the PCV to the take off on the runner along with the vacuum for the lights etc. as I say I maybe made a school boy error and should have connected the PCV to the front port. Currently running no PCV and all fine but will get some more hose and connect to the front port to see if it still runs fine before getting another PCV.
Drifting
Joined: Oct 2005
Posts: 1,528
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From: East London/SW Essex UK
I was going to 'chime-in' and ask if OP had tried running the car a night, looking for a grounding spark.......even better - remove hood and try again but under load (again looking for a renegade sparl trail.
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Joined: Jan 2020
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Just a quick up date, connected the pcv to the port at the bottom of the carb in the front, still firing on all 8 but I do need to do a bit of adjustment to the carb, I keep messing with the adjustment but can only get around 14 to 15 inHg, what I have read states I should be getting around 17+, having said that the cam is ever so slightly more aggressive so maybe that is why but now I am happy to drive the thing around without thinking I’m going to destroy two cylinders.
Melting Slicks
Joined: Dec 2014
Posts: 2,788
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From: Central UT
Just a quick up date, connected the pcv to the port at the bottom of the carb in the front, still firing on all 8 but I do need to do a bit of adjustment to the carb, I keep messing with the adjustment but can only get around 14 to 15 inHg, what I have read states I should be getting around 17+, having said that the cam is ever so slightly more aggressive so maybe that is why but now I am happy to drive the thing around without thinking I’m going to destroy two cylinders.
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