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73-87 Chevy _ GMC Trucks => Performance => Topic started by: bmaier on April 12, 2008, 11:24:34 pm

Title: throttle
Post by: bmaier on April 12, 2008, 11:24:34 pm: awhile back i installed a new intake manifold and carburetor on my 79 k10, everything went well, hooked up great, runs good. however, when i hit the accelerator to get goin at first it seems like i have to press the pedal fairly hard, not too hard, but it doesnt roll into it real easy. once im goin the pedal feels fine, its just that initial takeoff. its really no big deal, just one of those little things that i notice lol. im just wondering if maybe there is an adjustment i can make or something. i went from a quadrajet to edelbrock carb if that makes any difference.
Title: Re: throttle
Post by: Lt.Del on April 12, 2008, 11:35:29 pm: Look at your cable between the firewall and carb....check spring action, binding, etc...it happens only during taking off because you have to depress more at that time. Check the obvious: floor mat under pedal, any other obstruction. Play with the lever at the carb...see if it is tougher at a certain point. It could be the carb--ensure nothing is in the way of the butterflies, etc..
Title: Re: throttle
Post by: choptop on April 12, 2008, 11:48:28 pm: Both Edelbrock carbs I have ran were stiffer than the q-jet. 1st one I though it was me, second one, didn't pay alot of attention to it at first because I got used to the other one. Maybe normal???? ???
Title: Re: throttle
Post by: 77c15 on April 13, 2008, 05:45:25 am: My dads Edelbrock acts exactly the same way, but mine doesn't. It is most likely the throttle return spring (I bought a new one, we reused his).
Title: Re: throttle
Post by: VileZambonie on April 13, 2008, 10:43:44 am: Make sure the return spring isn't excessively stretched holding the throttle closed. If it is you may need to reposition it.
Title: Re: throttle
Post by: TexasRed on April 14, 2008, 06:45:12 am: Mine used to do that when the accel pump was moved to the bottom hole and not the middle hole on the linkage.
Title: Re: throttle
Post by: gold84gmc on April 15, 2008, 05:28:13 am: i would rather have a q-jet than an edelbrock...but thats just my opinion. to me it sounds like the throttle return spring............if anyone knows anything about q-jets look at my post in this same topic
Title: Re: throttle
Post by: Lt.Del on April 15, 2008, 09:17:51 pm: Quote
i would rather have a q-jet than an edelbrock...but thats just my opinion

You know Edelbrock makes the carbs that were once known as qjets.

http://www.edelbrock.com/automotive_new/mc/carbs_acc/performer.shtml (http://www.edelbrock.com/automotive_new/mc/carbs_acc/performer.shtml)
Title: Re: throttle
Post by: ccz145a on April 15, 2008, 09:31:53 pm: I believe those by edelbrock are carter afb's
Title: Re: throttle
Post by: Blue 82 on April 15, 2008, 09:45:13 pm: Quote from: ccz145a on April 15, 2008, 09:31:53 pm
I believe those by edelbrock are carter afb's

Weber USA made a bunch of Q-Jets for em.
Title: Re: throttle
Post by: ccz145a on April 15, 2008, 09:53:38 pm: Quote
Quote from: ccz145a on Today at 09:31:53 PM
I believe those by edelbrock are carter afb's

Weber USA made a bunch of Q-Jets for em.

Could be, just those in the link look like Carters. I would love to get my qjet working right again, it's a pre-smog '75 model. Rebuilt it twice with out much luck. Got a holley while I figure out where I went wrong.
Title: Re: throttle
Post by: bmaier on April 15, 2008, 11:51:21 pm: i've been super busy with work the past few days, but i will definitely check out what you guys have suggested. thanks for the input and i will let you know what goes on.
Title: Re: throttle
Post by: Captkaos on April 16, 2008, 03:37:04 pm: Quote from: SgtDel on April 15, 2008, 09:17:51 pm
You know Edelbrock makes the carbs that were once known as qjets.

http://www.edelbrock.com/automotive_new/mc/carbs_acc/performer.shtml (http://www.edelbrock.com/automotive_new/mc/carbs_acc/performer.shtml)

Those are like the Carter Thermo Quads. Edelbrock stopped purchasing the company that was supplying them Quadrajets.
Title: Re: throttle
Post by: ccz145a on April 16, 2008, 03:47:33 pm: Thermo Quads had a thermoplastic (bakelight) body with aluminum top and bottom. afb's were all aluminum, that's why I said. :) afb
Title: Re: throttle
Post by: Captkaos on April 16, 2008, 04:16:12 pm: Duh, didn't see that. I just grouped them all together.
Title: Re: throttle
Post by: DnStClr on April 16, 2008, 11:08:02 pm: Were they used for marine applications or auto?
Title: Re: throttle
Post by: ccz145a on April 16, 2008, 11:34:27 pm: I know early 70's chrysler land barges had em, don't think that counts for marine, tho. ;)

(http://www.carbsonly.com/Graphics/Carb%20Pics/bigpictures/Big%20Thermoquad.jpg)
Title: Re: throttle
Post by: truckdoctor on April 17, 2008, 05:41:27 pm: Just wondering if you are looking for more acceleration from a roll-on or from a dead stop? I don't know if the truck is automatic or not (can't remember if you posted this or not to be honest?) if it is an automatic and it doesn't respond the way it used to during a roll-on acceleration, It could be due to the kick down linkage to the transmission is either out of adjustment or not hooked up?

If you're driving at 45 and stomp the throttle and the truck slowly gradually climbs up to speed, it may be the kick down. If you're driving at 45 and stomp the throttle and the truck gears down and goes, forget what I said about the kick down.

All of the other ideas were great and about exhausted as ideas go, this wasn't mentioned so I thought I'd throw this one in.
Title: Re: throttle
Post by: bmaier on April 17, 2008, 08:44:16 pm: the kickdown works great, i had problems with that before but fixed it. i think it may be my return spring and i am talkin bout from a dead stop.