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madaca · 11-02-2008, 01:24 AM

Well today I disassembled the Rochester carbs and rebuilt them with a rebuild kit from auto zone. They had one in stock and it had my name on it. This was my first time ever rebuilding carbs. At first it seemed like a lot of parts but in the end it was pretty easy. I adjusted everything according to the directions. I also drained all the fuel out of my gas tank and treated the tank with some stuff that prevents rust. I reinstalled the tank and finished building the carbs. It was too late to put the carbs back on so I will be installing them in the morning and adding some fresh gas to the tank. I am really hoping it will start this time. Last Monday I adjusted the carbs some and was able to get it running real strong. It idled good once I adjusted the idle and sounded great. I let it run about 10 minutes and then it started idling funny. It eventually died. I restarted but whenever I gave it gas it kept wanting to bog out on me. I couldn't get it to rev good. I did notice an air leak coming from one of the top bolts of the carbs. I figured it needed some new gaskets so that it why I rebuilt the carbs. No telling if the carbs have ever been rebuilt before. I am really hoping this solves my problem. I want to hear that engine run again. It sounded so good when it did. I will keep you all updated if it works or not. Meanwhile I would be thankful for any suggestions or ideas as to what the problem may be.

jonzcustomshop · 11-02-2008, 08:22 AM

It was probably the accelerator pump, the rubber part that pushes the gas gets cracked, and it will work until you put pressure on it, then the cracked rubber gives way and it dies.
I just re-did mine , and that was the problem.
that air leak might be a vaccuum leak some times there is a hollow carb bolt that goes into the intake, they get clogged with carbon , or rust through...

madaca · 11-02-2008, 11:36 AM

The accelerator pump looks a little bad. I didn't see any visible cracks but I did see two spots on the edge of it that had real tiny pieces missing off the rubber part. Hopefully the new one solves the problem. I will be installing the carbs later today to see if it works.

joe231 · 11-02-2008, 11:46 AM

you have a multiple carb set-up?
how about pics?

madaca · 11-02-2008, 12:02 PM

No just the stock carb that came with the 283 v8. I will get some pics as soon as I begin reinstalling it. Im watching the grandchild right now so I have to wait till the wife gets home.

502tripower · 11-02-2008, 12:41 PM

I am assuming you have a Rochester 2-GC 2-barrel on a 170 HP 283? As others have said the accelerator pump. One thing to look for in these carb kits is the plunger for the accelerator pumps fit in the carb base. Make sure that it is not to big or to small. Also if you are using gas that has "Ethanol or E-85" This can be a problem on the rubber parts if they are not specifically rated for Ethanol or E-85. Check out this thread on the subject.

http://www.348-409.com/forum/showthr...highlight=fuel

madaca · 11-02-2008, 02:25 PM

Yup that is the carb I have. I just installed it and will be adding some gas pretty soon. I have to go to the parts store and get a hose that I found was all messed up. It is the bigger hose that connects to the carb in the back. It was pretty bad. Anyone know what that hose does? Im kinda new at these things but I learn fast.

502tripower · 11-02-2008, 06:42 PM

Quote:

Originally Posted by madaca

Yup that is the carb I have. I just installed it and will be adding some gas pretty soon. I have to go to the parts store and get a hose that I found was all messed up. It is the bigger hose that connects to the carb in the back. It was pretty bad. Anyone know what that hose does? Im kinda new at these things but I learn fast.

Sounds like a vacuum or PVC hose.

madaca · 11-02-2008, 07:49 PM

Ok everyone I need some help. I put the carbs back on and added some gas. I got it started but it keeps bogging out on me. When I give it gas it wants to die and sometimes it idles good and sometimes it doesn't. I'm getting back firing too when I give it gas. Also, when i give it gas it sounds like it's sucking a lot of air but I do not know much about carbs and all. I rebuilt the carb according to instructions and made proper adjustments with float and all. I backed out the air mixture screws 2 turns and then tried them at 1 and a half turn but nothing really changed. I am noticing some air leaking out of the front right bolt area where the carb bolts to the engine on the throttle side. I do not understand how air is leaking from there. Does anyone have any ideas? I also cleaned out all plugs. They were black. Any help is very appreciated. Here are some crappy pics. I had a little mishap with my cell phone and now the pictures look weird.

This is the where the air is leaking from the bolt.

skullboydeath · 11-02-2008, 08:55 PM

I rebuilted my roch I couple of weeks ago. Maybe I can help a little. If your leaking air that is probly your problem with it running rough. Check you gasket at the intake make sure it is good and make sure it is the right one those autozone kits usally come with serval differnt gaskets. If thats not it check the bolt make sure all the threads are good and nothing is stripped

madaca · 11-02-2008, 09:07 PM

I will check that tomorrow and see what I come up with. I know the gasket is seated properly but I need to look at it and find out what is causing air to seep out of that bolt hole. I am sitting here looking at the diagram that came with the carb kit and just noticed that I did something wrong. The two little balls that come with the kit (one is smaller than the other)....well I put the larger one in the pump intake but the diagram shows that it should be the small one. I also did not notice I was supposed to put the larger ball in the pump discharge hole with the spring and retainer. I completely forgot to put that larger ball in there. I do not know what exactly they do but I will be fixing that tomorrow. Other than that, everything else is good. I just need to figure out this air coming out of that bolt hole.

madaca · 11-04-2008, 11:10 PM

I opened up the carb again and place the small balls in the proper place. I think the carbs are good now. I have discovered that one of the reasons my truck is running badly is because timing is way off. I have started another thread here if anyone can help. Thanks for the help on this topic.

http://67-72chevytrucks.com/vboard/s...06#post2960106

madaca · 11-30-2008, 09:08 PM

I am still needing some help on this carb problem. Today I tried starting the truck again. I sprayed liquid around the carb while it was running and I can clearly see there are two vacuum leaks. Both leaks are at the front of the carb where it bolts into the engine. Air is leaking around those two bolts. I took the carb off and looked at the gasket and it seams fine. It is a new gasket and I made sure again that the area had no build up or anything that may be allowing air to pass by. I do not know what I should do to get this air to stop leaking from those two areas. Do I use a gasket sealer or something around the bolts? Any help is appreciated. Also, I noticed that when the truck is running it is popping every now and then I can see what looks like flame or spark trying to escape from the manifold on the passenger side of the truck where it connects to the exhaust. Is this being caused from the vacuum leak or something else.

**scotts62** · 11-30-2008, 10:25 PM

Sealer maybe a tiny bit but if fuel gets to it it wont last, the gasket should have fixed it..
The popping sounds to be timing, usually with a vacuum leak it will run really rough or not at all depending on where and how big the leak.

madaca · 11-30-2008, 10:42 PM

Yeah it is running pretty rough. It ran smooth for a little while today a few times but then it gets rough and then just wants to die. I messed with the timing some but I really need it to run longer so I can mess with it some more. If I put the choke on it runs but as soon as I let it off it will idle for a little while then die. The gasket I got came from autozone with the carb rebuild kit. I am wondering if I should see about getting another gasket from somewhere else. It is obviously not sealing properly.

**scotts62** · 12-01-2008, 08:35 AM

Yeah you probablly need to fix the vacuum leak first. just try checking oreillys and see if they have a different kind of gasket. Im not sure on the Qjets but the hollys you can spend just a little more and get the blue gaskets and they work really well, especially if you have to take apart more than once.

madaca · 12-01-2008, 11:28 AM

I will stop by Oriellys after work and see what they have. I think autozones seems to be too thin maybe. I remember when I took the carb off, the old one looked like it was a higheer quality gasket. It was thicker and had a texture to it. I think it was silver in color. I will post back when I change it out. Thanks

11-02-2008, 01:24 AM	#1
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	cross your fingers Well today I disassembled the Rochester carbs and rebuilt them with a rebuild kit from auto zone. They had one in stock and it had my name on it. This was my first time ever rebuilding carbs. At first it seemed like a lot of parts but in the end it was pretty easy. I adjusted everything according to the directions. I also drained all the fuel out of my gas tank and treated the tank with some stuff that prevents rust. I reinstalled the tank and finished building the carbs. It was too late to put the carbs back on so I will be installing them in the morning and adding some fresh gas to the tank. I am really hoping it will start this time. Last Monday I adjusted the carbs some and was able to get it running real strong. It idled good once I adjusted the idle and sounded great. I let it run about 10 minutes and then it started idling funny. It eventually died. I restarted but whenever I gave it gas it kept wanting to bog out on me. I couldn't get it to rev good. I did notice an air leak coming from one of the top bolts of the carbs. I figured it needed some new gaskets so that it why I rebuilt the carbs. No telling if the carbs have ever been rebuilt before. I am really hoping this solves my problem. I want to hear that engine run again. It sounded so good when it did. I will keep you all updated if it works or not. Meanwhile I would be thankful for any suggestions or ideas as to what the problem may be.

11-02-2008, 08:22 AM	#2
jonzcustomshop 1961 crewcab Join Date: Dec 2007 Location: missoula, mt Posts: 6,164	Re: cross your fingers It was probably the accelerator pump, the rubber part that pushes the gas gets cracked, and it will work until you put pressure on it, then the cracked rubber gives way and it dies. I just re-did mine , and that was the problem. that air leak might be a vaccuum leak some times there is a hollow carb bolt that goes into the intake, they get clogged with carbon , or rust through...

11-02-2008, 11:36 AM	#3
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers The accelerator pump looks a little bad. I didn't see any visible cracks but I did see two spots on the edge of it that had real tiny pieces missing off the rubber part. Hopefully the new one solves the problem. I will be installing the carbs later today to see if it works.

11-02-2008, 11:46 AM	#4
joe231 Registered User Join Date: Dec 2007 Location: Palmer, Alaska Posts: 13,821	Re: cross your fingers you have a multiple carb set-up? how about pics? __________________ *CHEVY ONLY*

11-02-2008, 12:02 PM	#5
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers No just the stock carb that came with the 283 v8. I will get some pics as soon as I begin reinstalling it. Im watching the grandchild right now so I have to wait till the wife gets home.

11-02-2008, 12:41 PM	#6
502tripower Registered User Join Date: Jan 2008 Location: Satsop, WA Posts: 606	Re: cross your fingers I am assuming you have a Rochester 2-GC 2-barrel on a 170 HP 283? As others have said the accelerator pump. One thing to look for in these carb kits is the plunger for the accelerator pumps fit in the carb base. Make sure that it is not to big or to small. Also if you are using gas that has "Ethanol or E-85" This can be a problem on the rubber parts if they are not specifically rated for Ethanol or E-85. Check out this thread on the subject. http://www.348-409.com/forum/showthr...highlight=fuel __________________ 1963' Chev Custom Cab 502, 67' 435hp 3X2 intake, 9" 4:30 Posi 1961 Impala SS 348/350 4-speed 3:70 Posi 1961 Bel-Air Bubble Top 283 Turboglide soon to have a 348 3X2 4-speed 1950 17' Fairliner twin cockpit barrel stern 312 Y block 1X1 intake Borg Warner 1:1 gear 1957 Fleetform 14' twin cockpit barrel stern 1969 BP-125 Merc 1949 Transitier 3-wheel forklift Crosley 4-Banger 98' FXD 2002 2500HD Last edited by 502tripower; 11-02-2008 at 12:41 PM.

11-02-2008, 02:25 PM	#7
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers Yup that is the carb I have. I just installed it and will be adding some gas pretty soon. I have to go to the parts store and get a hose that I found was all messed up. It is the bigger hose that connects to the carb in the back. It was pretty bad. Anyone know what that hose does? Im kinda new at these things but I learn fast.

11-02-2008, 07:49 PM	#9
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers Ok everyone I need some help. I put the carbs back on and added some gas. I got it started but it keeps bogging out on me. When I give it gas it wants to die and sometimes it idles good and sometimes it doesn't. I'm getting back firing too when I give it gas. Also, when i give it gas it sounds like it's sucking a lot of air but I do not know much about carbs and all. I rebuilt the carb according to instructions and made proper adjustments with float and all. I backed out the air mixture screws 2 turns and then tried them at 1 and a half turn but nothing really changed. I am noticing some air leaking out of the front right bolt area where the carb bolts to the engine on the throttle side. I do not understand how air is leaking from there. Does anyone have any ideas? I also cleaned out all plugs. They were black. Any help is very appreciated. Here are some crappy pics. I had a little mishap with my cell phone and now the pictures look weird. This is the where the air is leaking from the bolt. Last edited by madaca; 11-02-2008 at 07:50 PM.

11-02-2008, 08:55 PM	#10
skullboydeath Registered User Join Date: May 2008 Location: Johnson City, TN Posts: 45	Re: cross your fingers I rebuilted my roch I couple of weeks ago. Maybe I can help a little. If your leaking air that is probly your problem with it running rough. Check you gasket at the intake make sure it is good and make sure it is the right one those autozone kits usally come with serval differnt gaskets. If thats not it check the bolt make sure all the threads are good and nothing is stripped

11-02-2008, 09:07 PM	#11
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers I will check that tomorrow and see what I come up with. I know the gasket is seated properly but I need to look at it and find out what is causing air to seep out of that bolt hole. I am sitting here looking at the diagram that came with the carb kit and just noticed that I did something wrong. The two little balls that come with the kit (one is smaller than the other)....well I put the larger one in the pump intake but the diagram shows that it should be the small one. I also did not notice I was supposed to put the larger ball in the pump discharge hole with the spring and retainer. I completely forgot to put that larger ball in there. I do not know what exactly they do but I will be fixing that tomorrow. Other than that, everything else is good. I just need to figure out this air coming out of that bolt hole. Last edited by madaca; 11-02-2008 at 09:09 PM.

11-04-2008, 11:10 PM	#12
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers I opened up the carb again and place the small balls in the proper place. I think the carbs are good now. I have discovered that one of the reasons my truck is running badly is because timing is way off. I have started another thread here if anyone can help. Thanks for the help on this topic. http://67-72chevytrucks.com/vboard/s...06#post2960106

11-30-2008, 09:08 PM	#13
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers I am still needing some help on this carb problem. Today I tried starting the truck again. I sprayed liquid around the carb while it was running and I can clearly see there are two vacuum leaks. Both leaks are at the front of the carb where it bolts into the engine. Air is leaking around those two bolts. I took the carb off and looked at the gasket and it seams fine. It is a new gasket and I made sure again that the area had no build up or anything that may be allowing air to pass by. I do not know what I should do to get this air to stop leaking from those two areas. Do I use a gasket sealer or something around the bolts? Any help is appreciated. Also, I noticed that when the truck is running it is popping every now and then I can see what looks like flame or spark trying to escape from the manifold on the passenger side of the truck where it connects to the exhaust. Is this being caused from the vacuum leak or something else.

11-30-2008, 10:25 PM	#14
scotts62 One day... Join Date: Apr 2008 Location: Tuttle, Ok Posts: 9,243	Re: cross your fingers Sealer maybe a tiny bit but if fuel gets to it it wont last, the gasket should have fixed it.. The popping sounds to be timing, usually with a vacuum leak it will run really rough or not at all depending on where and how big the leak. __________________ Scott 93 crew cab build Project 62

11-30-2008, 10:42 PM	#15
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers Yeah it is running pretty rough. It ran smooth for a little while today a few times but then it gets rough and then just wants to die. I messed with the timing some but I really need it to run longer so I can mess with it some more. If I put the choke on it runs but as soon as I let it off it will idle for a little while then die. The gasket I got came from autozone with the carb rebuild kit. I am wondering if I should see about getting another gasket from somewhere else. It is obviously not sealing properly.

12-01-2008, 08:35 AM	#16
scotts62 One day... Join Date: Apr 2008 Location: Tuttle, Ok Posts: 9,243	Re: cross your fingers Yeah you probablly need to fix the vacuum leak first. just try checking oreillys and see if they have a different kind of gasket. Im not sure on the Qjets but the hollys you can spend just a little more and get the blue gaskets and they work really well, especially if you have to take apart more than once. __________________ Scott 93 crew cab build Project 62



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12-01-2008, 11:28 AM	#17
madaca Registered User Join Date: Oct 2008 Location: Longview, tx Posts: 145	Re: cross your fingers I will stop by Oriellys after work and see what they have. I think autozones seems to be too thin maybe. I remember when I took the carb off, the old one looked like it was a higheer quality gasket. It was thicker and had a texture to it. I think it was silver in color. I will post back when I change it out. Thanks

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