Not getting gas in carb

[MayheM]

Hey guys, first post on the forum. Have been lurking some, but anyway to the point.
So.. I bought a rough 1980 GMC longbed a few weeks ago and have been going through things and trying to get it running.

Let me also say that I have absolutely no mechanical or fabricating knowledge. I've wanted a square for about 5 years and wanted to learn to work on it myself, and this is my way of doing it.

I rebuilt (or attempted to, was my first ever attempt to rebuild) the quadrajet that was on it. Got a new starter, checked spark(plugs probably should be changed anyway) etc. I got the truck to fire up with some gas poured into the carb, but it would die when that ran out.

I replaced my fuel pump today and the fuel filter on the front of the carb. However it still isn't getting gas inside the carb.. I'm guessing this because I had a cracked fuel line going into the carb and when I tried to start it, the line sprayed fuel. So I replaced that line and put a new filter in. There was gas in the line and where the filter goes, but there doesn't seem to be any gas getting into the carb.. So I guess I'm gonna have to tear it back apart? What should I check and will this require a complete rebuild?

[bd]

Is the filter behind the carburetor fuel inlet nut installed backwards?

[Mario]

If you know it's getting fuel up to the carburetor, then yeah, you're going to have to remove it and tear it down again.  In my experience in dealing with carbs that have had gas stored in them for a long period of time, you have spend a lot of time ensuring that they are clean.  An algae growth can clog up all the small passages.  Those passages carry fuel and vacuum air.  I would get a use once aluminum pan and boil water and detergent with the carb body in it.  Pull it out, and spray the passages with carb cleaner, and blow compressed air through them also.  You could spin small soft wire through some of them as well.  Sometimes it is a trial and error process until the carburetor gets clean enough to run properly.  Don't get down, just keep trying.  Good luck, Man! 

[MayheM]

Is the filter behind the carburetor fuel inlet nut installed backwards?

I don't think so, the side with the hole is facing the nut. That's how the other came out.

If you know it's getting fuel up to the carburetor, then yeah, you're going to have to remove it and tear it down again.  In my experience in dealing with carbs that have had gas stored in them for a long period of time, you have spend a lot of time ensuring that they are clean.  An algae growth can clog up all the small passages.  Those passages carry fuel and vacuum air.  I would get a use once aluminum pan and boil water and detergent with the carb body in it.  Pull it out, and spray the passages with carb cleaner, and blow compressed air through them also.  You could spin small soft wire through some of them as well.  Sometimes it is a trial and error process until the carburetor gets clean enough to run properly.  Don't get down, just keep trying.  Good luck, Man!

Alrighty, I probably should of been more thorough with my first cleaning and rebuilding. I bought Cliff's how to rebuild/modify rochester quadrajets book. Maybe I'll do some of the stuff in there now that I'm a bit more familiar with the carb. I kind of just took it apart and cleaned the parts w/ carb cleaner and put the rebuild kit in and slapped it back on.

Should I look into maybe getting a new carb or just go with this one? I'd kind of like a new one but at the same time I'd like to get this one working and know every piece of it..

[bd]

If you want to learn, there is no better way than rolling up your sleeves and digging in.  But, be methodical and don't get the cart ahead of the horse....

BTW, the inlet filter was installed correctly.   

------------------------------

Here's a place to start.  It's time to perform some basic checks before you tear that carb back apart.  Incidentally, how old is the fuel in the tank?  Check all of the rubber fuel hoses for cracks/splits/resiliency/sponginess and replace with fuel rated hose as needed.

Pick up a vacuum/pressure gauge and check the fuel pump pressure (5-7 PSI), suction (>20" Hg), and volume (minimum of 1 quart fuel in 30 seconds of cranking - healthy pumps typically deliver 1 qt in ~20 sec).  When performing fuel related tests, remain alert and have a fire extinguisher at hand.  Work with an assistant.  Wipe up any fuel that spills right away.  No sparks or flames!  Disconnect power from the distributor, so the engine doesn't start.

Once you've verified adequate fuel delivery to the carburetor, remove the float bowl cover and recheck the float level.  Make sure the needle valve is properly hooked over the end of the float and not through one of its "holes."  And, make sure adjustments are performed precisely, per factory specifications.  If you have to tear it apart again, as Mario pointed out, make sure passages are clean and thoroughly blown out with compressed air.

A word to the wise - get the vehicle running correctly, before you modify the carb using Ruggles' book.  No need to introduce additional variables when you are trying to sort out a problem.

[MayheM]

If you want to learn, there is no better way than rolling up your sleeves and digging in.  But, be methodical and don't get the cart ahead of the horse....

BTW, the inlet filter was installed correctly.   

------------------------------

Here's a place to start.  It's time to perform some basic checks before you tear that carb back apart.  Incidentally, how old is the fuel in the tank?  Check all of the rubber fuel hoses for cracks/splits/resiliency/sponginess and replace with fuel rated hose as needed.

Pick up a vacuum/pressure gauge and check the fuel pump pressure (5-7 PSI), suction (>20" Hg), and volume (minimum of 1 quart fuel in 30 seconds of cranking - healthy pumps typically deliver 1 qt in ~20 sec).  When performing fuel related tests, remain alert and have a fire extinguisher at hand.  Work with an assistant.  Wipe up any fuel that spills right away.  No sparks or flames!  Disconnect power from the distributor, so the engine doesn't start.

Once you've verified adequate fuel delivery to the carburetor, remove the float bowl cover and recheck the float level.  Make sure the needle valve is properly hooked over the end of the float and not through one of its "holes."  And, make sure adjustments are performed precisely, per factory specifications.  If you have to tear it apart again, as Mario pointed out, make sure passages are clean and thoroughly blown out with compressed air.

A word to the wise - get the vehicle running correctly, before you modify the carb using Ruggles' book.  No need to introduce additional variables when you are trying to sort out a problem.

The gas is pretty much fresh,  a small amount from last Thursday and all the rest from yesterday. I'll have to get a vacuum/pressure gauge and look up how to check that stuff. Then I'll go from there and check the things you've mentioned.. hopefully I don't have to rebuild it again but if I do its not that big of a deal. I'll just have to do it right this time haha.

Oh and by using the book I just meant following it on the rebuild part not the modding part, don't think I'm up for that yet.

[bake74]

     Look at it this way.  You are learning something new that you can use from now on.  Do not look at it like you screwed up and have to do it over again, makes digging into it much more enjoyable.   

[MayheM]

Do I need to get another rebuild kit or will the gaskets be fine still?

Also, the previous owner said the head gaskets needed to be replaced. There was definitely water in the oil, so should I just go ahead and change them when I take the carb off to rebuild it? Or should I try to get it running first to see what it does? It didn't knock when I started it by pouring gas in the carb but it smoked quite a bit.

If I should change them.. what is a decent torque wrench? I don't have one and have never used one. Also how will I know which gaskets to get? I noticed there were quite a few different ones when I looked them up

[bd]

Begin here...

...Check all of the rubber fuel hoses for cracks/splits/resiliency/sponginess and replace with fuel rated hose as needed.

Pick up a vacuum/pressure gauge and check the fuel pump pressure (5-7 PSI), suction (>20" Hg), and volume (minimum of 1 quart fuel in 30 seconds of cranking - healthy pumps typically deliver 1 qt in ~20 sec).  When performing fuel related tests, remain alert and have a fire extinguisher at hand.  Work with an assistant.  Wipe up any fuel that spills right away.  No sparks or flames!  Disconnect power from the distributor, so the engine doesn't start.

Once you've verified adequate fuel delivery to the carburetor, remove the float bowl cover and recheck the float level.  Make sure the needle valve is properly hooked over the end of the float and not through one of its "holes."  And, make sure adjustments are performed precisely, per factory specifications.  If you have to tear it apart again, as Mario pointed out, make sure passages are clean and thoroughly blown out with compressed air.

You will "probably" be okay reusing the carb gaskets as long as none tear during disassembly.

Reinstall the carburetor before continuing, so you don't have fuel blowing everywhere during the next steps.

-----------------------

Concerning water in the oil:

On a 60+ degree day do you see profuse white smoke from the exhaust after running the engine for 30 seconds to a couple of minutes when first started cold? 

Water in the oil isn't necessarily a blown head gasket.  Deteriorated intake gaskets or cracks in the castings can also be a source of water in the oil.  Begin your evaluation by checking cylinder condition. 

Remove all the spark plugs and keep them in order by cylinder.  Do any of the spark plugs look wet or have coolant on them?  Are any of the spark plug electrodes/insulators particularly clean relative to the others?  Have an assistant crank the engine while you watch under the hood.  Stay clear of the fan and belts!  Watch for a white cloud or mist blowing out of a cylinder on the first engine revolution - that is an indication of water in that cylinder.  Next, run a (dry) compression check to identify any low cylinders and write down the results.  Run a second (wet) compression check on each cylinder after squirting two oil can shots of 30 wt oil into each cylinder, one at a time, in turn, as you recheck the compression.  Post all your results, dry and wet.  You may be able to rent a compression gauge from your local parts house.  You won't need a torque wrench for these initial checks.

[MayheM]

Begin here...

...Check all of the rubber fuel hoses for cracks/splits/resiliency/sponginess and replace with fuel rated hose as needed.

Pick up a vacuum/pressure gauge and check the fuel pump pressure (5-7 PSI), suction (>20" Hg), and volume (minimum of 1 quart fuel in 30 seconds of cranking - healthy pumps typically deliver 1 qt in ~20 sec).  When performing fuel related tests, remain alert and have a fire extinguisher at hand.  Work with an assistant.  Wipe up any fuel that spills right away.  No sparks or flames!  Disconnect power from the distributor, so the engine doesn't start.

Once you've verified adequate fuel delivery to the carburetor, remove the float bowl cover and recheck the float level.  Make sure the needle valve is properly hooked over the end of the float and not through one of its "holes."  And, make sure adjustments are performed precisely, per factory specifications.  If you have to tear it apart again, as Mario pointed out, make sure passages are clean and thoroughly blown out with compressed air.

You will "probably" be okay reusing the carb gaskets as long as none tear during disassembly.

Reinstall the carburetor before continuing, so you don't have fuel blowing everywhere during the next steps.

-----------------------

Concerning water in the oil:

On a 60+ degree day do you see profuse white smoke from the exhaust after running the engine for 30 seconds to a couple of minutes when first started cold? 

Water in the oil isn't necessarily a blown head gasket.  Deteriorated intake gaskets or cracks in the castings can also be a source of water in the oil.  Begin your evaluation by checking cylinder condition. 

Remove all the spark plugs and keep them in order by cylinder.  Do any of the spark plugs look wet or have coolant on them?  Are any of the spark plug electrodes/insulators particularly clean relative to the others?  Have an assistant crank the engine while you watch under the hood.  Stay clear of the fan and belts!  Watch for a white cloud or mist blowing out of a cylinder on the first engine revolution - that is an indication of water in that cylinder.  Next, run a (dry) compression check to identify any low cylinders and write down the results.  Run a second (wet) compression check on each cylinder after squirting two oil can shots of 30 wt oil into each cylinder, one at a time, in turn, as you recheck the compression.  Post all your results, dry and wet.  You may be able to rent a compression gauge from your local parts house.  You won't need a torque wrench for these initial checks.

Thanks a ton! I was wanting to get it running to check smoking and whatnot. I'll try to get the carb re cleaned and assembled this weekend if I can, then I'll try going through your steps. I never thought of looking at all of the plugs for differences. . And a compression gauge was on my shopping list. I just looked up how to check it the other day. I'll be back with all my results hopefully early next week.

Thanks again for spending your time helping me out.


EDIT: I just got home and ordered that vacuum/pressure kit and also a compression test kit. They should be here next week, I'm gonna go ahead and tear the carb apart this weekend. I'll completely disassemble it this time and soak it before spraying out all of the passages and whatnot. I'm pretty sure some of them are blocked up just from my inspection when i took the top off of it while it was still on the truck.

[rich weyand]

When you blow out passages, try to blow them out in the direction opposite air/fuel flow.  Whatever blocked them got in at the entrance, and will leave easier headed back the way it got in in.  You don't want to embed anything deeper.  Hint: all flow in a carb is toward the intake manifold.

Also: BE EXTREMELY CAREFUL WITH CARB CLEANERS.  All are extremely flammable, and combustion of most of them results in poisonous decomposition byproducts.  For example, don't smoke anywhere near the stuff, and don't burn your paper towels or rags when the job is complete if they contain carb cleaner.

[MayheM]

When you blow out passages, try to blow them out in the direction opposite air/fuel flow.  Whatever blocked them got in at the entrance, and will leave easier headed back the way it got in in.  You don't want to embed anything deeper.  Hint: all flow in a carb is toward the intake manifold.

Also: BE EXTREMELY CAREFUL WITH CARB CLEANERS.  All are extremely flammable, and combustion of most of them results in poisonous decomposition byproducts.  For example, don't smoke anywhere near the stuff, and don't burn your paper towels or rags when the job is complete if they contain carb cleaner.

Thanks for the tips! I disassembled it again today, then soaked and sprayed it, then reassembled it just now.

I think I got the passages flowing. I wasn't exactly sure where they all flowed to but spraying carb cleaner through them seemed to spray it out somewhere else instead of back at me.

There is 1 part on the side of the carb that I'm not sure is on right. It is on how my pics were from before it was taken off the truck, but I don't know for sure that is right. It's a little thing that stops the secondaries(I think that's what they are? the bigger ones) from opening if it is in a certain position. However nothing is keeping it from falling in front of them or holding it away. I'll try to get a pic up.

Still have to clean some of the rust up, was just mocking it up. I can get more pics if needed, thats just what I was talking about.. There is nothing actuating it, it just sits freely. Is it on wrong? that's how it was originally there when i got the truck.

Heres a link to the pic http://imgur.com/2UhDWF1

[bd]

The secondary lockout is a small pivoting lever that prevents secondary throttle opening prior to the choke opening fully.  If you force the choke linkage all the way open, the lockout should pivot away from the secondary throttle shaft pin and allow secondary opening.  A good pic will be ideal for verification.

[MayheM]

The secondary lockout is a small pivoting lever that prevents secondary throttle opening prior to the choke opening fully.  If you force the choke linkage all the way open, the lockout should pivot away from the secondary throttle shaft pin and allow secondary opening.  A good pic will be ideal for verification.

I threw a pic up. I can take more if you need.

[bd]

That appears correct.  When the choke closes the lever will engage the pin on the secondary throttle shaft and prevent secondary opening.