No fuel to Carburetor

[chekingese]

454 won't start with out pouring gas into carb. then it stalls when gas runs out.pour,, start, stall.over n over again.rear elec fuel pump working.engine mech. pump new.quadra jet rebuilt, then rechecked 2x. nothing.Frustration level topping out!fuel filter in carb.removed,new in line filter installed .5yr old gas in tank, will run on it, tried previous with it.Can someone please help?

[Lefty]

If an engine will run with gas poured directly into the carb. But not run without doing that, it's not getting fuel.
If you have verified that the electric and mechanical pumps are working, and that the fuel lines are not clogged from the tank to the mechanical pump, then you need to disconnect the fuel line directly at the carb. and tun the engine over. verify that you see fuel coming out of the line. If you do see fuel, reconnect the line. The issue will be inside the carb.
You will need to remove the top of the carb. to access the float mechanism. The float actuates a small stopper that allows fuel into the float bowl. verify that the passageway is clear, by blowing thru the fuel line inlet and listen for air coming out of the orifice with the float in the down position. If you hear air, and it's not difficult to blow thru, proceed to the next step. If not, then you need to clear the blockage.
Next, it is possible that rust,dirt, or other debris has clogged either the main jet or secondary jet. If so, no fuel will pass from the float bowl into the engine. To check for this, you need to totally empty the float bowl of fuel. Either absorb it with lint-free paper towels (never use regular paper towels.. a piece of lint can go into the jet assemblies or further) or remove the carb. and turn it upside down to empty.
Look at the bottom of the empty float bowl and you should see two shiny brass screws with holes in the center of them. If you see anything blocking the holes, you can try to gently pick it out. If you do not see anything, the debris could be further inside the metering assembly or any one of a number of passages. Clearing them will require a total dissasembly of the carb. to find and clear the blockage and a rebuild. If you are unsure of rebuilding the carb., I'd highly recommend stopping now and either buying a freshly rebuilt carb. or take your carb. to a qualified rebuilder. Rebuilding a Quadrajet is not a job for a beginner, and requires a few special tools to do properly. you would need a float level gauge to set the float height, and jet removal tools as a minimum. Plus, you need the knowledge to properly setup and adjust the carb. afterwards.

[DRMousseau]

mmmm,... new rebuilt carb eh???
If your CERTAIN your getting fuel TO the carb,...


...remove center wire from middle of distributor cap and coil. Make CERTAIN choke is fully closed, and with accelerator fully depressed, activate starter and turn engine over for several seconds. Then, using a mirror, look down carb throat, beyond throttle plate and choke, for fuel. It should be quit wet down there. If not, then you may have other carb issues, such as plugged jets, stuck float or no fuel in carb.


Again...use a mirror to look down the carb throat, be sure ign is off when doing this. Actuate the throttle fully and find some manner to hold open BOTH, the choke AND the throttle plate, and activate again with full view beyond both plates. You SHOULD see fuel being manually pumped into the carb throat with throttle movement and activation. IF NOT,... then activate fuel pumps briefly, (Fuel should be flowing freely at inlet from fuel source), and repeat the above observations. MAKE SURE IGN IS OFF and ALWAYS use a mirror when making such observations!!!


If your still unable to pump fuel into Carb throat, you likely have float bowl issues. Perhaps a plugged inlet, stuck float needle,or obstructed needle seat. This assumes a functioning accelerator pump within the carb, and it IS a new rebuild, right??? If you CAN see fuel pumped in by throttle activation, then a pump or two, or three,... should be enough to INITIATE engine starting. Your "flooding the engine" in much the same way as physically pouring fuel into the carb throat! This is an unsafe condition and I will caution you to be EXTRA careful!!!


Replace IGN coil wire on distributor and try starting again. If you can initiate engine start in this manner, you might also be able to "keep it runnin" by constantly "pumpin' the pedal".


IF your getting fuel into the engine, thru the carb, and everything is wet,.... and it will still only run when MORE is added, then I would suspect a serious vacuum leak somewhere that is preventing the proper fuel/air ratio for normal running operation. It WAS jus recently installed, right???


First,... let's be SURE your gettin' fuel into the engine THRU the carb jets!!! Then we'll explore adjustments and possible vacuum leak issues if necessary. If you cant get any fuel thru the carb, and it IS a new rebuild, then someone was a bit sloppy in carb assembly and/or installation.

[MotorPro]

Unplug the power wire to the distributor, disconnect the fuel line from the carb,put the line into a jar,crank engine , if you get gas in the jar you have a carb problem,if not you have a pump filter or tank problem

[circleD]

If you have the quadra jet there'll be a tube type filter on the front of the carb plus one on the frame rail about middle ways back near the walk in door. And if the lines are original there might be a collapsed area somewhere.

[Rickf1985]

I would check that filter by the entry step before anything else because from the sounds of it this has been an ongoing problem. That filter is missed quite often because nobody knows it is there. Do not be surprised if it is not there, mine was gone. Someone decided it was too much of a pain to replace it and just put a piece of fuel line in it's place. I place my money on that filter being clogged. Dr. M, There is no coil wire on the HEI ignition, you have to pull the power wire wire to the distributor. I do not like pulling the coil wire for two reasons, the high voltage has to go somewhere and it will. It will either short through the windings inside the coil or it will spark down the outside of the coil, this is on an external coil I am talking about now. With that spark down the outside of the coil plus the gas vapor from playing with the carb and all of that being inside of a vehicle, NOT a good idea!

[DRMousseau]

YOU ARE RIGHT!!! And it only takes a spark!!! Even if you cant smell it,... the air below your nose can be saturated with vapors!!!
I hate workin around carbs in flooded situations,... actually, I jus hate workin around gasoline!!!


oh,... and that gas, is it 6mos old??? or 5 YEARS OLD?!?! In Florida's extreme heat, gasoline gets pretty bad in a short time!!!

[Lefty]

I was going to add.. 5yr old gas is probably not going to fire, even if it goes thru the carb into the engine.. At that age, it's closer to turpentine than gasoline. Could be that it's running off the fresh gas you are pouring in, but dying because that 5yr old gas won't fire.

[chekingese]

hi guys, AS i had said,i even dumped old gas into the carb and it ran for a few seconds after i quit pouring then stalled just like with new gas.the gas is 5 yrs old[at least 4] how would i get rid of 20-30 gallons of old gas?fire dept training?"all filters and pumps ok.I'm pretty sure that the problem lies in the bottom of the float bowl within the orifices or associated chambers therein after reading todays posts. tomorrow i'm going to check with a friend who owns a junkyard about a mile from here.and see if he has a quadrajunk to replace this one. trouble is I;m as usual trying to fix something with no money!!Larry

[circleD]

Fire departments can't use gasoline for training thanks to the EPA. So the gas is getting from the tank to the carb correct? And you're pouring gas into the carb also? I'm just making sure that we can narrow down the issue.

[chekingese]

yeah that's it.so what do you do with that much old gas? maybe tomorrow i'll rig up a 5 gal can of fresh gas at the rear fuel pump and pump fresh gas into the lines from there . try that before I take the carb off again to check the jets.

[MotorPro]

How do you know gas is getting to the carb? Don't start changing things before you narrow down where the problem is. It is very unlikely that both the Jets and the excelerateor pump are plugs. If you are getting fuel out of the line at carb the next step is a stuck float. Engines should fire on even 30 year old gas. Won't run worth a crap but it will start.

[LJ-TJ]

Fix something with no money!!!!!!!! That's why your here. Welcome to the thrifty, frugal funny farm. We're all broke. :)rotflmao trying to fix something with no money. What's that old saying. Misery love company.

[Rickf1985]

You do not have to go all the way to the back to rig a fresh can of gas. Just run a line from the suction side of the engine fuel pump into a five gallon can of fresh gas. Be aware that trying to run five year old gas is just asking for stuck valves and bent/ broken pushrods. I completely agree that the problem is most likely in the carb if there was gas left in there to evaporate. The inside of that carb will be brown, sticky and probably green in aces and the sccelerator pump will be toast. New gas has alcohol in it which is the best solvent around so once you get fresh gas flowing it will clean out the whole system. Be prepared to change a lot of filters for a while.

[LJ-TJ]

Yep! if you follow the gas line in the carb back it will take you to the fuel pump. The other line coming out of the fuel pump should be the line going to the gas tank. If it is a rubber gas line then disconnect it at the gas tank end not the fuel pump end and put the end NOT connected to the fuel pump but connected to the gas tank end into a fresh can of gas. Take a little gas and pour it into the carb and try and start it. It should fire, If it does let it run a while to get some new gas through the carb. If that works put some Marvel Mystery Oil in the gas and let it run for a while. Hm?

[Rickf1985]

TJ, your line choices are not making sense. All you have to do is take the line from the tank off of the fuel pump on the engine. Replace that line with a long piece of line and put that on the pump and in a can of gas. No need to go to the back of the coach. This way bypasses all filters except the one in the carb and also eliminates the electric pump and any leaky lines.

[76PRROW]

In the case of my 440 not wanting to start I replaced the fuel filter like you did but checked it to see if there was restriction in the filter itself it was completely clogged with rust. I had been pouring gas in my carb to get her to run to figure out I wasnt getting fuel.  However after replacing the filter with a new one it still would not start. I read somewhere that you must repeat the process of filling the carb and starting the engine up to 5 times to prime the fuel line and the carb. for me it started on the 4th try. I hated having gasoline in the coach and every time I pored fuel in I replaced both the carb cover and the doghouse with the latches... Hope this helps and be careful.


Should probably drain your tank as well, or siphon out as much as you can and mix fresh fuel in there.

[chekingese]

Ive probably started it 20 times over the past 3 weeks.getting sick of it.I didn't work on it today,too darn hot! junk yard friend couldn't help me. reason that I'm going to the elec pump in rear is that its a positive,controlable,easier to get to,no starter cranking to get it primed again and its in the shade! thanks for your help. larry

[TripleJ]

Theres been a ton of advice here, but you really should determine what the actual problem is before you start changing parts, switching pumps, taking the carb apart again...

That is, don't assume it is in the pump or carb if you don't know what the fuel pressure and volume is at the carb inlet.

For anyone with any type of fueling issue, IMO the FIRST thing to do is to replace any inline fuel filters, they are maintenance item and should/will clog in time.  SECOND thing is to determine the fuel pressure and volume at the carb inlet.  Generally around 5-6psi and AT LEAST a pint per 30 seconds CRANKING (not running)... write it down and go from there

There are a hundred tips and tricks you could try and that other people have tried, you might even guess correct, but you should try to understand the super simple system that these carbed engines use.  It will help a ton.  Just my opinion

[chekingese]

I thought I had found the problem...not quite and made a new one.I studied the rebuild diagram and found that the "power piston assy. had not been touched or cleaned or nothing.So i took it apart and completely cleaned it.it had not been moving at all.BUT in the process i messed with the setting that is next to it which the instructions say shouldn't be changed,oops.I also lost the cupped seal from the top of the piston assy.on the floor of my dirty garage. there was one in the kit but it doesn't fit exactly right. live and learn.

[chekingese]

how/where would i learn the super simple system these carbs use???just finished reading the previous post ,larry

[circleD]

I've read and talked to a lot of people about carbs. I've learned the little bit I know by trial and error. I can figure out what's wrong but mess up other stuff also when reassembling. So don't worry and take your time and learn where to get parts cheap and quick. The guys at my local auto store know what I need when I walk in so make friends with them.

[Oz]

how/where would i learn the super simple system these carbs use???just finished reading the previous post ,larry

Super simple!

In Rx for RV Performance and Mileage.  Available in the club store:
http://www.classicwinnebagos.com/forum/index.php?action=store;sa=view;id=184

This is an excellent book, written in such simple terms, even I understand it~!
 
And, it has a section on common problems with the different brands and proven tips and tricks to correct them.

(You get it free with a Life Member upgrade too, along with access to around 100 manuals for furnaces, refrigerators, generators, awnings, commodes, stoves, and more)

[Rickf1985]

In any diagnosis there is a pattern that needs to be followed. If you keep jumping to different areas or trying things that are not related you will be chasing the problem forever. I specialized in carburetor and electrical when I had my shop and quadrajets were one of my favorites. You are finding out about not following the repair tree the hard way. I and others will try to help but you have to pay attention to what we say.

[TerryH]

          "follow the repair tree"
I like that and it is excellent advice.
Reminds me of "Alice's Adventures In Wonderland":
- begin at the beginning and go on till you come to the end: then stop. -