Author Topic: new carb?  (Read 7737 times)

Offline roofdoctor

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new carb?
« on: January 05, 2013, 04:07:09 pm »
I have an 84 c10 ,305 (H).  I have pulled the carb, not sure whether to put in an edelbrock 600 or get a rebuild kit.  (Rochester4bbl#17084226).  I do not need performance really, it is a work truck, but I put alot of miles on it. With a rebuild, I can put everything back how it was; but I have to rebuild a carburetor :( .   Will a new one require any additional brackets or spacers or anything? Also, even though I have a manual, and have been studying this problem for  week, I am still fairly clueless about which vacuum hoses are which, and where they go if I put in the edel.  and how to hook up the electric choke?  A new rochester is out of the budget.

Thanks in advance for any advice/help
84 Chevy c10 305 (H) silverado

Offline 81_Chevy

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Re: new carb?
« Reply #1 on: January 05, 2013, 09:07:45 pm »
for the new carb you would have to get an adapter plate to go onto your stock manifold to fit the edelbrock, you would have to hook up the electric choke (if it doesnt already have one). IMO if you want the new carb buy it. but if your streched on money go down to the local auto parts store and get a rebuild kit $100 ish. if your not sure how to take it apart and stuff a good trick is to setup a video camera and take the carb apart slowly and then if you get stuck on the rebuild just look back on the video.

on my truck im just putting a new carb on it cuz im sick of messing with my q jet trying to get it tuned.
81 Chevy K20 350 4" Rough Country lift ridin on 35's ; 2 12 inch Subwoofers w/ a custom interior

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Offline Captkaos

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Re: new carb?
« Reply #2 on: January 06, 2013, 02:12:22 pm »
I would rebuilt what came on there.  That is a R4-M4ME Qjet (Electric Choke on the side).  A rebuild kit is less than $30.  There is a post on here recently showing how to rebuild one..

Offline roofdoctor

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Re: new carb?
« Reply #3 on: January 06, 2013, 10:09:45 pm »
thanks guys. I am leaning toward rebuild, heard that from a buddy of mine too. will search for that post
84 Chevy c10 305 (H) silverado

Offline roofdoctor

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Re: new carb?
« Reply #4 on: January 07, 2013, 11:14:39 am »
anyone have any tricks for replacing vacuum hoses? Easier when warm?
Also, what if the idle solenoid is bad- can it be bypassed?
84 Chevy c10 305 (H) silverado

Offline Bigred85

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Re: new carb?
« Reply #5 on: January 07, 2013, 03:57:50 pm »
Try (National Carburetors) good reputation. I just got a professional rebuilt quadrajet for under $200. Runs like a top.

Offline roofdoctor

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Re: new carb?
« Reply #6 on: January 07, 2013, 04:17:13 pm »
I found them online, that is a good recommendation but I  already took it to a local company. Ill see how they do. Also I found that 5/32 vac line is alot easier to work with than 7/64 in this case, lol
84 Chevy c10 305 (H) silverado

Offline 81_Chevy

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Re: new carb?
« Reply #7 on: January 08, 2013, 01:40:02 pm »
when i replaced my vac lines i just went down to  O'Reilly's and got like a 4 ft roll of some and cut them to the same length as the old ones and replaced them. what do you mean by the idle solenoid? ive never heard of this before.
81 Chevy K20 350 4" Rough Country lift ridin on 35's ; 2 12 inch Subwoofers w/ a custom interior

Eagle Scout - 2012 Proud to be one!

Offline roofdoctor

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Re: new carb?
« Reply #8 on: January 09, 2013, 09:12:27 pm »
there is a small cylinder mounted on a bracket in front of the throttle linkage with a 1-wire connection and an adjustment screw.  Two sources including Haynes say this is how to adjust the idle speed.   I have been told they tend not to function by this time.  I guess I will have to try it out when I get the carb back on. 
84 Chevy c10 305 (H) silverado

Offline jaredts

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Re: new carb?
« Reply #9 on: January 09, 2013, 09:50:27 pm »
It sounds like the idle compensator.  If it is it only kicks in to bump up your idle when the air conditioning kicks on.  You would adjust it by turning on the a.c. and adjusting the idle speed.  The idle speed screw should be easy to spot because when you open the choke flap and move the throttle the throttle bracket will rest on it.

Offline roofdoctor

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Re: new carb?
« Reply #10 on: January 10, 2013, 08:14:06 pm »
I guess that explains why that other guy called it an "a/c step motor" .  Thanks for clearing that up.
84 Chevy c10 305 (H) silverado

Offline jaredts

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Re: new carb?
« Reply #11 on: January 10, 2013, 10:34:17 pm »
Step motor is definitely not a good description of that device.  Its just a solenoid with an adjustable stop.  A step motor is a rotary motor with a certain number of steps per revolution used in printers and small motion control machines. 

Offline roofdoctor

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Re: new carb?
« Reply #12 on: January 14, 2013, 09:29:27 am »
Well with help from you guys and this site, I got it put back together.  While I had the carb off and was replacing the vac lines, I installed new valve cover gaskets as a first step in stopping oil leak(s?).  Replaced EGR and PCV valves.  And did a ton of cleaning, being careful to keep
distributor covered.  Still not gotten half of the oil off though. 
Now, it starts rough- always did in the cold- but then it winds up and up and up, blows a lot of smoke, and quits.  Anyone got an idea?
I've had this truck for a year, have been using 20/50 per recommendation of guy I bought it from, which is maybe bad, idk, this time I used 5/30.
When I pulled the valve covers, everything looked...well...uh...black...
Some of the smoke seems to be coming off the catalytic converter, hard to tell on account of the oil burning off the surface of the exhaust. I believe everything behind the exhaust manifolds is new-ish.
84 Chevy c10 305 (H) silverado

Offline bake74

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Re: new carb?
« Reply #13 on: January 14, 2013, 06:40:12 pm »
     If by cleaning you mean you were washing the oil off and it was running down to the ground, then it is going to smoke a lot until you finish cleaning, or it burns it off.
     As far as the idle going up and up, are you sure you have no vacuum leaks ?  The other idea is distributer, ( I know you said you covered it ), did you check to make sure it is dry inside ?
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Offline jaredts

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Re: new carb?
« Reply #14 on: January 14, 2013, 08:19:31 pm »
Have you hooked up the choke wire to the side of the carb.?  Properly set the choke?  Does the idle wind up in a matter of seconds or minutes?  Black smoke?