Quadrajet Help! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

GMC Guy · 10-07-2009, 04:12 PM

so i bought a rebuild kit for the quadrajet on my 350. eventually i will put a new edelbrock or holley on there, but a $30 kit was just more in the budget than a $300 carb. yesterday i pulled it off the engine, and starting cleaning with carb cleaner, a toothbrush, and compressed air. worked great, you wouldn't believe the amount of crap that it had in there. so then i proceeded to carefully take it apart and further clean. then replace the seals inside along with a few other things that came in the kit. well that's where i'm stuck

i can't for the life of me, figure out how this thing goes back together. i've looked up videos and stuff off google, no luck.

can anyone help me out? or is there someone that i might be able to send it to?
(a shop wanted around $400 to rebuild it

)

cowboy5683 · 10-07-2009, 04:22 PM

what carb number do you have..i have a 79 also..i can post some pics of mine and you can study the choke linkage and what not from there..prolly just the linkage that is throwin ya right?

GMC Guy · 10-07-2009, 04:29 PM

when i get home home i'll post some pics of what's giving me trouble. but yes it is mainly the linkage

cowboy5683 · 10-07-2009, 04:59 PM

Here are the promised pics..Hopefully I got enuff angles clear enuff to help ya!
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cowboy5683 · 10-07-2009, 05:00 PM

Couple more!!
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GMC Guy · 10-07-2009, 07:05 PM

thanks man, every little angle helps. are you going to rebuild that quad?

GMC Guy · 10-10-2009, 06:34 PM

UPDATE: last night i finished assembling the carb and this morning i bolted it back on the engine, connected all the vacuum lines and cables. went to fire it, nothing, tried a couple more times, nothing, poured some gas down the carb, fired for a few seconds. then i pulled the fuel line to make sure it's getting fuel, and it is, or at least the fuel pump is pumping gas. really don't know what else to try

Please help...

cowboy5683 · 10-10-2009, 08:56 PM

Sounds to me like yer getting fuel to the carb but it isnt gettin in the carb..check to make sure the fuel filter is installed correctly..the hole at the end of the filter should be at inlet side of the housing..meaning if you were to pull it out the filter hole should be what the fuel hits first..If that is correct make sure its a good filter the next step would be to make sure the fuel bowl is filling up and the float level is correct and the float is good and the needle and seat are instaled correctly and not clogged..The little hanger for the needle should NOT be hung in the float arm holes..just hang it on the lil metal bridge and it wil be fine..lemme know what happens.

GMC Guy · 10-10-2009, 09:21 PM

the filter is new, along with the needle and seat, and i made sure to hang it correctly. hopefully it didn't slip though. also i set the float level at 15/32" that's what the specs called for, but i did have to bend it down from about 6/32". i'll go check the filter to see it it's backwards and get back to you. thanks for all the great help and advice

GMC Guy · 10-10-2009, 09:37 PM

ok, filter was in correct, but when i pulled it out is was pretty dry in there. even the filter wasn't soaked with gas. shouldn't gas have come pouring out from the carb when i removed the filter?

donut · 10-10-2009, 08:53 PM

Is the fuel getting INTO the carb? (check if accelerator pump is "squirting")
I don't remember if the filter is directional or not. Could also be crud blocking the inlet between the filter and needle/seat assembly.

79gmcc15 · 10-10-2009, 09:52 PM

how long did you try to start it? from my experience it can take a little while to start a dry carb. try keeping it going with gas/starter fluid. you might need 2 people to help.

GMC Guy · 10-10-2009, 10:00 PM

ya i've been doing alone, now i'm just waiting for my dad to get home to give me a hand. you really do need another person to watch the engine while the other person cranks it.

79gmcc15 · 10-10-2009, 10:27 PM

ya, When ever I've replaced my carb it has always taken longer then I "think" for it to fill up.

GMC Guy · 10-10-2009, 10:40 PM

could my fuel pump have gone bad? i'm going to pick up some starting fluid and keep trying i guess.

cowboy5683 · 10-11-2009, 07:00 AM

Yes yer fuel pump could be bad..but u said earlier u had fuel at that point..kinda wierd..follow the other steps I lined out and see where yer at from there.lemme know what happens..If you need personal help my cell is 951 - 385 -3512..I may not answer right away but leave message and I will call back asap n help u if I can.

cowboy5683 · 10-11-2009, 07:09 AM

Looking at the other replies it looks like yer goin in the right direction..except it couldnt b spark if it runs when ya pour gas down the vent n it starts..gotta be a fuel problem that is not allowing it to get into the bowl and then continuing to come in n allowing it to run..15/32" is right for that carb..call me n if I dont answer I will call you back n try to help you A.S.A.P.

GMC Guy · 10-11-2009, 04:53 PM

ok, so i pulled the carb back off today, and took it apart. the bowl was completely dry. so somehow fuel is not filling in the bowl. while i had it off i filled the bowl with fuel, and the float rose how it should. the needle and seat are also new. so after filling it with a little gas, i put it back on and it only fired the gas that was in there, then nothing....soo for some reason the carb is not filling with gas, even though it has fuel pressure going into it...
Any Suggestions are greatly appreciated.

79gmcc15 · 10-10-2009, 10:48 PM

well, one thing you could do is take the line off and turn the motor till it pumps some out. it does not need a lot of PSI to run the motor, like 5 PSI. so don't be surprised if it does not come out like crazy. maybe have a cup ready so you don't spill it everywhere. that might make it easier to start knowing the gas has made it from the tank to the tube. just be patient with it, don't crank and crank and crank. go like 10 seconds then stop for 5 to keep from getting the starter hot.

GMC Guy · 10-10-2009, 10:53 PM

ok thanks i'll give that a shot

GMC Guy · 10-11-2009, 12:00 AM

ok, so i am getting fuel to the line, and hopefully into the carb. but it still won't turn over on it's own, only when i pour a little gas into it.

79gmcc15 · 10-11-2009, 12:34 AM

next step would be to look down the carb to see if it is squirting fuel in. if it is, then you need to check for spark problems. if it is not then something is up with the carb.

GMC Guy · 10-11-2009, 12:38 AM

well it ran when i took it off earlier this week, but i'll check tomorrow if its squirting fuel.

billnorman · 10-11-2009, 05:49 PM

This site helped me a lot. It may help you. http://dyeager535.topcities.com/CCCqjetdiagram.html

GMC Guy · 10-11-2009, 06:02 PM

thanks, that is a helpful diagram

10-07-2009, 04:12 PM	#1
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Quadrajet Help! so i bought a rebuild kit for the quadrajet on my 350. eventually i will put a new edelbrock or holley on there, but a $30 kit was just more in the budget than a $300 carb. yesterday i pulled it off the engine, and starting cleaning with carb cleaner, a toothbrush, and compressed air. worked great, you wouldn't believe the amount of crap that it had in there. so then i proceeded to carefully take it apart and further clean. then replace the seals inside along with a few other things that came in the kit. well that's where i'm stuck i can't for the life of me, figure out how this thing goes back together. i've looked up videos and stuff off google, no luck. can anyone help me out? or is there someone that i might be able to send it to? (a shop wanted around $400 to rebuild it ) __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-07-2009, 04:22 PM	#2
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! what carb number do you have..i have a 79 also..i can post some pics of mine and you can study the choke linkage and what not from there..prolly just the linkage that is throwin ya right?

10-07-2009, 04:29 PM	#3
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! when i get home home i'll post some pics of what's giving me trouble. but yes it is mainly the linkage __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-07-2009, 04:59 PM	#4
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! Here are the promised pics..Hopefully I got enuff angles clear enuff to help ya!

10-07-2009, 05:00 PM	#5
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! Couple more!!

10-07-2009, 07:05 PM	#6
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! thanks man, every little angle helps. are you going to rebuild that quad? __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-10-2009, 06:34 PM	#7
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! UPDATE: last night i finished assembling the carb and this morning i bolted it back on the engine, connected all the vacuum lines and cables. went to fire it, nothing, tried a couple more times, nothing, poured some gas down the carb, fired for a few seconds. then i pulled the fuel line to make sure it's getting fuel, and it is, or at least the fuel pump is pumping gas. really don't know what else to try Please help... __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-10-2009, 08:56 PM	#8
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! Sounds to me like yer getting fuel to the carb but it isnt gettin in the carb..check to make sure the fuel filter is installed correctly..the hole at the end of the filter should be at inlet side of the housing..meaning if you were to pull it out the filter hole should be what the fuel hits first..If that is correct make sure its a good filter the next step would be to make sure the fuel bowl is filling up and the float level is correct and the float is good and the needle and seat are instaled correctly and not clogged..The little hanger for the needle should NOT be hung in the float arm holes..just hang it on the lil metal bridge and it wil be fine..lemme know what happens.

10-10-2009, 09:21 PM	#9
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! the filter is new, along with the needle and seat, and i made sure to hang it correctly. hopefully it didn't slip though. also i set the float level at 15/32" that's what the specs called for, but i did have to bend it down from about 6/32". i'll go check the filter to see it it's backwards and get back to you. thanks for all the great help and advice __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)] Last edited by GMC Guy; 10-10-2009 at 09:25 PM.

10-10-2009, 09:37 PM	#10
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! ok, filter was in correct, but when i pulled it out is was pretty dry in there. even the filter wasn't soaked with gas. shouldn't gas have come pouring out from the carb when i removed the filter? __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-10-2009, 08:53 PM	#11
donut Registered User Join Date: Aug 2009 Location: S.C. Posts: 1,593	Re: Quadrajet Help! Is the fuel getting INTO the carb? (check if accelerator pump is "squirting") I don't remember if the filter is directional or not. Could also be crud blocking the inlet between the filter and needle/seat assembly. __________________ '86 C-30 dually, 454/tbh400 '73 K-20 350/350/205 (sold ) I'm kinda like duct tape- no real purpose, but handy to have around.

10-10-2009, 09:52 PM	#12
79gmcc15 Gettin It One Pice At A Time Join Date: Oct 2004 Location: everett, washington Posts: 2,688	Re: Quadrajet Help! how long did you try to start it? from my experience it can take a little while to start a dry carb. try keeping it going with gas/starter fluid. you might need 2 people to help. __________________ RIP ELJAY Work In Progress 1979 GMC C1500 Trailering Special. Getting the truck done, one piece at a time. “You can tell a lot about a fellow’s character by his way of eating jellybeans.”Ronald Reagan “I don’t know the key to success but I know the key to failure is trying to please everybody.” Bill Cosby

10-10-2009, 10:00 PM	#13
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! ya i've been doing alone, now i'm just waiting for my dad to get home to give me a hand. you really do need another person to watch the engine while the other person cranks it. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-10-2009, 10:27 PM	#14
79gmcc15 Gettin It One Pice At A Time Join Date: Oct 2004 Location: everett, washington Posts: 2,688	Re: Quadrajet Help! ya, When ever I've replaced my carb it has always taken longer then I "think" for it to fill up. __________________ RIP ELJAY Work In Progress 1979 GMC C1500 Trailering Special. Getting the truck done, one piece at a time. “You can tell a lot about a fellow’s character by his way of eating jellybeans.”Ronald Reagan “I don’t know the key to success but I know the key to failure is trying to please everybody.” Bill Cosby

10-10-2009, 10:40 PM	#15
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! could my fuel pump have gone bad? i'm going to pick up some starting fluid and keep trying i guess. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]



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10-11-2009, 07:00 AM	#16
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! Yes yer fuel pump could be bad..but u said earlier u had fuel at that point..kinda wierd..follow the other steps I lined out and see where yer at from there.lemme know what happens..If you need personal help my cell is 951 - 385 -3512..I may not answer right away but leave message and I will call back asap n help u if I can.

10-11-2009, 07:09 AM	#17
cowboy5683 Registered User Join Date: Jun 2009 Location: San Bernardino CA Posts: 94	Re: Quadrajet Help! Looking at the other replies it looks like yer goin in the right direction..except it couldnt b spark if it runs when ya pour gas down the vent n it starts..gotta be a fuel problem that is not allowing it to get into the bowl and then continuing to come in n allowing it to run..15/32" is right for that carb..call me n if I dont answer I will call you back n try to help you A.S.A.P.

10-11-2009, 04:53 PM	#18
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! ok, so i pulled the carb back off today, and took it apart. the bowl was completely dry. so somehow fuel is not filling in the bowl. while i had it off i filled the bowl with fuel, and the float rose how it should. the needle and seat are also new. so after filling it with a little gas, i put it back on and it only fired the gas that was in there, then nothing....soo for some reason the carb is not filling with gas, even though it has fuel pressure going into it... Any Suggestions are greatly appreciated. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-10-2009, 10:48 PM	#19
79gmcc15 Gettin It One Pice At A Time Join Date: Oct 2004 Location: everett, washington Posts: 2,688	Re: Quadrajet Help! well, one thing you could do is take the line off and turn the motor till it pumps some out. it does not need a lot of PSI to run the motor, like 5 PSI. so don't be surprised if it does not come out like crazy. maybe have a cup ready so you don't spill it everywhere. that might make it easier to start knowing the gas has made it from the tank to the tube. just be patient with it, don't crank and crank and crank. go like 10 seconds then stop for 5 to keep from getting the starter hot. __________________ RIP ELJAY Work In Progress 1979 GMC C1500 Trailering Special. Getting the truck done, one piece at a time. “You can tell a lot about a fellow’s character by his way of eating jellybeans.”Ronald Reagan “I don’t know the key to success but I know the key to failure is trying to please everybody.” Bill Cosby Last edited by 79gmcc15; 10-10-2009 at 10:50 PM.

10-10-2009, 10:53 PM	#20
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! ok thanks i'll give that a shot __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-11-2009, 12:00 AM	#21
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! ok, so i am getting fuel to the line, and hopefully into the carb. but it still won't turn over on it's own, only when i pour a little gas into it. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-11-2009, 12:34 AM	#22
79gmcc15 Gettin It One Pice At A Time Join Date: Oct 2004 Location: everett, washington Posts: 2,688	Re: Quadrajet Help! next step would be to look down the carb to see if it is squirting fuel in. if it is, then you need to check for spark problems. if it is not then something is up with the carb. __________________ RIP ELJAY Work In Progress 1979 GMC C1500 Trailering Special. Getting the truck done, one piece at a time. “You can tell a lot about a fellow’s character by his way of eating jellybeans.”Ronald Reagan “I don’t know the key to success but I know the key to failure is trying to please everybody.” Bill Cosby

10-11-2009, 12:38 AM	#23
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! well it ran when i took it off earlier this week, but i'll check tomorrow if its squirting fuel. __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

10-11-2009, 05:49 PM	#24
billnorman Registered User Join Date: Mar 2009 Location: glen burnie md Posts: 174	Re: Quadrajet Help! This site helped me a lot. It may help you. http://dyeager535.topcities.com/CCCqjetdiagram.html

10-11-2009, 06:02 PM	#25
GMC Guy Registered User Join Date: May 2009 Location: Sparks, NV Posts: 913	Re: Quadrajet Help! thanks, that is a helpful diagram __________________ Greg 1974 GMC 1/2 Ton SWB Fleetside L33 5.3/4l65e .................__ ............._____l __\__ ..............l_(O)_ l___(O)]

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