I dropped and cleaned the tank a while back, and then my water pump went. I replaced it and the fan belts. Before dropping the tank the contents had turned to varnish.
Now, with all reassembled, it turns over briefly, but no fuel seems to be flowing and it shuts off. 2 oz of fuel in the carb lets it kick over about twice.
The strainer in the (new) fuel pump was filthy. I've replaced it (the filter coming into the carb is clean), but it still kicks one briefly and dies.
I removed the strainer bolt, and no fuel comes out as I crank.
I'll clip the fuel line out of the tank tomorrow to add an in-line clear filter, but is there anything else I can do or examine? Or does this make it time to install the switched electric fuel pump back at the tank?
thanks
hawk
The best way to completely prime the system is to remove the inlet from the Carby, and using a pump, suck all the air out of the fuel line, which at the same time, fills the system with fuel.
If this doesn't happen, then there is a problem somewhere.
Bruce. >:D
As filters were clogged, it is possible that old crap in the fuel system is plugging the line. I would suggest disconnecting the line at the fuel pump and the tank (sorry) and cleaning it out with mineral spirits or something similar and trying it again.
Since you have gone this far, the he hard part is already done. While the lines are disconnected, plug 1 end and add light pressure to the other. If the metal line holds pressure then good. If not then you have a crack/pinhole leak in the metal line somewhere.
After all is good there, connect it at the tank and suck fuel from the tank to the pump priming the line as Bruce suggested.
After you drive thru a tank or 2, replace the filter's again.
Jeff
I too am thinking you have a leak or blockage in the fuel line. Seafoam sitting for a while does a decent job of breaking up sludge.
Try running the suction hose from the fuel pump to a portable gas can and see if it will stay running that way. At least then you will know your pump is good. If you have an outboard tank around with an extra fitting that is a little safer than just a gas can and hose.
One of the first things I do on a new to me car is install a clear filter usually between the hard line from the back and fuel pump. I leave it there for a tank or two. If it stays clean I know the tank isn't too bad and remove it. If it gets dirty you know the tank is bad and will have to be dealt with, in the mean time you stock up on filters.
Yes, likely you have a leak or even more likely clog and the fuel pump strainer is your indicator. I worked on a mechanical restoration of 72 Eldorado a year ago and replaced the fuel pump plus all rubber lines. I would disconnect the rubber lines at fuel tank and let them drop down into a vessel. Then disconnect rubber lines at fuel pump. Using compressed air blast the lines clear with fuel pump side and have contents discharge into the vessel - probably need to secure the rubber into vessel. This way you know the lines are clear. If a lot of debris was found, then you may need to blast the sock free (inside tank)of debris with compressed air too. Then of course clear the fuel line from carb to fuel pump and replace fuel filter.
Obviously you replaced all rubber lines front and back of steel lines.
Keep in mind the fuel filter is at the pump and the fuel strainer is at the carb. If you have a fuel filter at the carb that is wrong and maybe the source of the problem. Check shop manual. The fuel filter was at carb in 75, but not sure when transition was made.
All of the rubber to the tank was replaced when I dropped the tank and remounted. The old rubber was so petrified I had to cut most off . . .
The fuel pump is also new, and the filters are the ones that pop up on Napa's computer.
Which of the lines on the fuel tank is the intake? I have the big bolt with the filter, and two more small lines near one another. For that matter, what is the third line. In, out, and ???
I do plan on adding a clear filter, and leaving it--I was unable to come up with a sock for the tank (but if I drop it again, I figure I'll get an EZMasher to use in it's place, http://schmidling.com/empp.htm (http://schmidling.com/empp.htm)).
Is the line out of the tank 5/16?
And blowing out the line with a compressor makes a lot of sense (and I need to cut or remove at the tank, anyway, to put in the extra filter).
On a fuel filter note . . . a friend's family drove deep into Mexico to visit family each year in a VW hippiemobile. His father added an extra fuel filter--from a Model T! He'd stop every 100 miles or so and scrape it out with a screwdriver, but it got enough of the gunk out that he could run on Mexican fuel.
hawk
I believe by 72 they feed line was a 3/8. 60's they used a 5/16, not sure when the change was. Pretty much all GM in the 70's to the end of carbs was 3/8 feed line, 5/16 vent, 1/4 return.
On the pump the big nut is the feed up to the carb. The 3/8" nipple is the suction from the tank. The 1/4 nipple is the return back to the tank.
The nut one is often damaged from getting sized into the pump. Its a fairly tight bend so if you end up having to install a section of hose make it fairly long so it doesn't kink. I use marine hose for things like that, the marine hose had double wall thickness so doesn't kink as easy as the standard stuff does.
I'm not sure if the return has any sort of regulator or if its just a partial constant bypass. It was standard equipment on AC equipped cars. The idea is it keeps the fuel flowing to reduce the chances of vapor lock. Its on AC cars because they figure stopped in traffic with the AC adds a lot of heat load so that is your best chance of vapor lock.
Pump being new doesn't do anything for me these days. My current new one is a Carter which used to be a good name but this one clanks. Not sure what I am going to try next.
When you replaced the hoses, did you have them well marked as to which was the supply and which was the return? If you are trying to suck fuel thru the return line you won't get to far.
When you remove the rubber ones again be sure the metal ends are the same diameter.
Jeff
Jeff
I guess I'll jack it up and get a picture of what goes where tomorrow.
I'm *pretty* sure I drove it after the tank went back on and before starting on the water pump. I remember going for gas, and it seemed empty to a knock yesterday . . . I put in about 3 gallons.
And if memory serves, the fuel line was the only nipple of the largest size (there are five in three different sizes).
Now I'm getting paranoid . . .
There is a fuel diagram in your shop manual.
Reading between the lines, it looks like you may have switched some of the lines with the rubber connections. In the future best to do this one at a time or mark them, that is what I do to spare myself looking through the fuel diagram. At the pump, that is easy - one with the nut is to carb, larger of two nipples is suction, smaller is return. I think there are three steel front to back lines, supply, return, and vent to canister. Make they are all connected correctly, as otherwise no fuel will be delivered to engine. As I remember there are a few more than three at the tank, for venting and pollution control.
Generally the fuel lines are all different rubber hose sizes, partially to avoid a mix up.
Pieces of memory are drifting back into place.
I had remembered going to get the gas, but that could have gone into lawnmowers.
But I took the car around the corner for gas.
More importantly, I drove it the 6 or 7 miles to church: I remember dithering about whether using the 5 gallon kegs of water that I'd filled in the summer would be a problem, or if I needed to change the water in them.
So it's near certain that this car drove at least 10 or 20 miles with the fuel hoses in this configuration.
It's occurred to me that it might be useful to keep around something, such as a glass funnel connected to fuel hosing, and perhaps a stand for it, that could be used for debugging . . .
Make it simple.... just suck on the supply line to the pump. If gas comes out you are good-if not then time to jack it up and have fun.
Jeff
Richard:
Check out below.
https://www.opgi.com/searchpart.asp?level=0&vehicle=cadillac&year=1955&keyword=fuel+sock
Ciao,
mario
I went another round or two today.
The pump definitely draws:
http://dochawk.org/caddie/pump_works.m4v (http://dochawk.org/caddie/pump_works.m4v)
(video even includes a splash!)
I then replaced the 3/8" hose from the fuel line to the pump, and after the pump (the former was limp, while the latter was chewed up from having been rubbed by the belt.
And then I added 11 gallons to the tank, just to be *sure* there was plenty of fuel in there and it wasn't sucking air.
Still wouldn't start, just the coughs from the priming gas.
I then connected the fuel line to the compressor rather than pump The fuel in the tank gurgled.
I also disconnected the output of the fuel pump, and nothing came out as the starter span for several seconds.
So I'm obstructed in the hard fuel line, the couple of inches of 3/8" fuel line connecting it to the tank, or the tank itself, correct?
What should I do next?
Quote from: dochawk on June 10, 2017, 07:10:03 PM
I then connected the fuel line to the compressor rather than pump The fuel in the tank gurgled.
I also disconnected the output of the fuel pump, and nothing came out as the starter span for several seconds.
Did you re-fill the line following the blowing back into the tank? Fuel pumps don't like sucking on an empty line.
Bruce. >:D
Quote from: The Tassie Devil(le) on June 10, 2017, 08:10:57 PM
Did you re-fill the line following the blowing back into the tank? Fuel pumps don't like sucking on an empty line.
err . . . uhm . . .
How do I do that?
hawk
Well, suck the petrol back up the line till it reaches the pump, then re-connect the hose to the pump.
Bruce. >:D
PS. How much pressure did you use to get the bubbles in the tank? Simply blowing? or full compressor pressure?
Quote from: The Tassie Devil(le) on June 10, 2017, 09:44:30 PM
Well, suck the petrol back up the line till it reaches the pump, then re-connect the hose to the pump.
Isn't that likely to give me a mouthful of gasoline?
Quote from: The Tassie Devil(le) on June 10, 2017, 09:44:30 PM
PS. How much pressure did you use to get the bubbles in the tank? Simply blowing? or full compressor pressure?
I slowly turned it up from off until it engaged, and then a bit more. Probably 15-20 psi.
Quote from: dochawk on June 11, 2017, 10:26:39 AM
Isn't that likely to give me a mouthful of gasoline?
;D Yeah, so? Join a very large crowd. Or ---
https://shop.advanceautoparts.com/p/mityvac-selectline-hand-vacuum-pump-mitmv8030/10050916-P?c3apidt=21513946754&gclid=CITr-uOAttQCFQuraQodff8L_g&gclsrc=aw.ds
Not sure how the system works on your car, but I would try with a vacuum pump at the inlet of the carburetor. Just remove the pipe from the carburetor and pump on it and see what comes out, if anything. Might also be some air or debris that is removed this way. If you have a vacuum pump its a fast test.
A mouth full of gasoline (seriously) can be hazardous...even fatal. I commonly use what I would describe as a ketchup 'squeeze' bottle with the pointy cone top for starting a siphon for example.
If you have a compressor, remove the fuel cap and insert your blow nozzle into the 2" fuel inlet where you pump your gas into. Wrap and tightly SEAL the opening and the blow nozzle together with a damp rag and 'pressurize' the tank. This will force the fuel to the engine. Initially, You can fashion a cup or catch at the engine, fuel supply line to view your success as it's hard to be in two places.
In the southwest we have 'sweat' bees, 🐝 that look like bees but hover more like a humming bird. FYI: They do not sting you. They build cocoons in ANY small (pencil size) open hole. I've had brand new fuel line just hanging around or laying in the shop...it will often be completely plugged with a cocoon, and quite an effort is required to dislodge it. It's very easy to install a new piece of fuel hose and NOT realize it's plugged by these critters. An open fuel line (or vacuum line ) on your car, whilst the tank is out ect, is also inviting these critters. 🐝🐛
Primer bulb like you used to see on outboard motors?
Quote from: dochawk on June 11, 2017, 10:26:39 AM
Isn't that likely to give me a mouthful of gasoline?
I insert a length of clear plastic hose before sucking so that I can see when to stop sucking.
QuoteI slowly turned it up from off until it engaged, and then a bit more. Probably 15-20 psi.
That is a fair amount of pressure, and may be sufficient to blow past any obstructions.
Bruce. >:D
Quote from: V63 on June 11, 2017, 10:54:10 AM
If you have a compressor, remove the fuel cap and insert your blow nozzle into the 2" fuel inlet where you pump your gas into. Wrap and tightly SEAL the opening and the blow nozzle together with a damp rag and 'pressurize' the tank. This will force the fuel to the engine. Initially, You can fashion a cup or catch at the engine, fuel supply line to view your success as it's hard to be in two places.
If the car has a fuel return line the pressure will bypass the pump and the gas won’t flow. Ask me how I know.
Quote from: Glen on June 12, 2017, 02:36:56 AM
If the car has a fuel return line the pressure will bypass the pump and the gas won’t flow. Ask me how I know.
You are correct, if you don't accumulate enough air pressure, volume and duration.
It's never failed me...in fact it's located system leaks before. If the return remains a concern...simply clamp the return hose with vice grips.
There is one situation to be mindful of...and that's if the fuel pump (mechanical) diaphragm is compromised to allow fuel to flow into crankcase. There is a weep hole in the side of the fuel pump designed to leak to notify diaphragm is leaking.
In stubborn cases it's a good method to loosen the fuel pump inlet to verify fuel is getting there. Then move loosened line to pump discharge, followed by filter inlet...and finally at carbie.
Don't forget there can be a filter (restriction) just inside the carb casting (Rochester)
My thinking at the moment is to disconnect the fuel line *into* the pump, set it to drain into a glass dish, and then pressurize the tank.
But from other comments, should I be disconnecting and capping the return line, too?
Would not doing so allow too much pressure on the pump diaphragm?
And it has occurred to me that after leaving the tank entirely off for some months and remounting, I did not have this problem. Wouldn't the gas line have dried out when I did that?
hawk
I would disconnect the inlet line at the pump...and just try and get some fuel to there. ..If no luck then you might need pinch off the return. I'm assuming you have a respectable shop compressor? The weaker your compressor is the more positive of a seal required at the filler. You Could jack up the back of the car too. Be prepared it could start siphoning...have another vise grip to pinch the supply line until you can connect it.
I have both an eight gallon and two gallon compressor at hand :)
A thought, a variant on pressurizing the tank using a rag as a simple seal:
What about using a shop vac to apply suction to the fuel line at the pump end? Will it generate enough suction?
hawk
Pressurising the fuel tank won't really work as the air inside will get out through the ventilation pipes, and the Charcoal canister.
Bruce. >:D
Safety first. Don't blow air into the fuel tank or pressurize. You can atomize a large amount of fuel and get a nasty flash fire.
Sounded like what you verified, the hard line is plugged. If the tank contents were bad, the line can not be any better. I'd replace the line because there's no way to tell what shape the inside is after you unblock it, but that's just my good practice. Start clean and then you don't have to filter out anything.
ps:
I'd check the brake lines and brake fluid, as well. If fluid is yellow or cloudy, it needs changed and system flushed.
Quote from: dochawk on June 14, 2017, 08:38:09 PM
A thought, a variant on pressurizing the tank using a rag as a simple seal:
What about using a shop vac to apply suction to the fuel line at the pump end? Will it generate enough suction?
hawk
No no no. The fumes from the gas can get ignited by the motor brushes. I think most shop vacs have warnings about not vacuuming up flammables.
Quote from: Glen on June 15, 2017, 01:32:42 AM
No no no. The fumes from the gas can get ignited by the motor brushes. I think most shop vacs have warnings about not vacuuming up flammables.
:o
OK,none of *that*!
I've found $4 pump at Harbor Freight. They also have the one mentioned on the first page for $40.
They also have https://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html (https://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html), which uses compressed gas to drive a vacuum. Supposedly forR12 and R134, for which it has connectors--but there's no apparent "out"; it may just be venting the vacuum (so how could it possibly be appropriate for coolant???)
You need a VERY large compressor to operate one of those pumps as they require a huge volume of air. Even then, they don't work that well.
My larger compressor is specced for it, but the notion that gas would simply ooze out of the plastic container was a deal-breaker.
I'm going with the $4 pump--at that price, I don't care if the gasoline ruins it, and it will get the flow going into a glass collection bowl for me.
If your goal is to collect the fluid you are sucking something like this already does that. Its not $4 but would save you the time piecing together a container and all the lines.
https://www.harborfreight.com/brake-fluid-bleeder-92924.html
I'm not trying to collect it; just to fill the fuel line since the pump isn't succeeding while sucking on air.
Once any comes out, I think I'm done.
Gosh, I sure hope I don't need to drain the tank to drop it again . . .
The 55 we just bought has a lot if crap in the tank. I fact I just removed the tank last nite. To get it running before we bought it, we just hooked a fuel line into a bottle of gas. The pump did it's thing and it ran.
An earlier post suggested there may be a blockage at the carb, etc. Hooking a line up as I described would take 5 minutes. It would verify the pump and the line to the carb.
Jeff
Quote from: Jeff Rose CLC #28373 on June 19, 2017, 04:22:49 PM
The 55 we just bought has a lot if crap in the tank. I fact I just removed the tank last nite.
For my '72, the shop manual calls for cleaning out with hot water.
*AFTER* i wrestled it to the bathtub, I learned about the drain on the water heater that fits a hose . . .
QuoteTo get it running before we bought it, we just hooked a fuel line into a bottle of gas. The pump did it's thing and it ran.
An earlier post suggested there may be a blockage at the carb, etc. Hooking a line up as I described would take 5 minutes. It would verify the pump and the line to the carb.
I posted the video above--the pump *definitely* draws and pumps; my issue is before the pump--and likely, a dry fuel line.
Well, *that* was stupid. ::)
Let me guess: the hole on the filter in the fuel pump should point down from the pump, and the flow is from outside the filter to the inside, then the hole . . .
A quick test with the hand pump showed gas easily available from the tank.
Then I connected the hose to the pump output, had my wife crank, and . . . nothing.
But gas started dripping on me as I removed the filter.
*sigh*
So tomorrow I'll buy another just to get the gasket . . . (it got torn going in and out)
then back to fixing vacuum lines and adjusting the carb.
and then to learn about timing . . .
hawk
grr.
No dice.
I put it in hole down, reconnected everything, and it still doesn't do it.
I guess I'll try without the filter to see if it still pumps into a recovery dish tomorrow, but I'll have to jack it up for that.
And I thought I was going to get a short drive today >:(
Could someone please confirm the correct direction--hole on filter into pump, or out (i.e., is intake through the paper and out through the hole, or vice verse. It seems that the hole needs to face the output of the pump.
Here is a picture of my fuel pump.
If I am correct, the hoses are different sixes.
Bruce. >:D
Thanks.
I indeed have three different size hoses on it.
The burning question, though, is which way the fuel filter *inside* the pump goes.
Is the pump arm on the cam gear correctly? If you unhook the lines and stick your finger over one and crank the engine do you feel it sucking?
I think you can run that pump without a filter for testing purposes
Jeff
The pump definitely draws; I linked to the video on the first page (http://dochawk.org/caddie/pump_works.m4v (http://dochawk.org/caddie/pump_works.m4v)).
The car has travelled several miles with this pump in place. I went into a filter-changing binge after replacing the water pump.
The best candidate at the moment is the pump filter being installed wrong.
Quote from: dochawk on July 03, 2017, 12:05:05 PM
The burning question, though, is which way the fuel filter *inside* the pump goes.
According to the ’72 shop manual (page 6-80) the filter should be installed with the open end of the filter seated inside of the nut.
HTH
Quote from: Glen on July 04, 2017, 02:15:20 AM
According to the ’72 shop manual (page 6-80) the filter should be installed with the open end of the filter seated inside of the nut.
*d'oh*
The number of times I've looked in the shop manual while doing this, and it didn't occur to me that *that* would be there . . .
On the bright side . . .
After attaching line at every step, and testing with and without the filter . . . gas pumped, but still no start.
Only *then* did it occur to me that the filter at the carb could be directional, too . . .
And, sure enough, after having to dismount the carburetor and choke to undo that bolt (in *what* world does that setup make sense??? I suppose it would be easy without the compressor in the way . . .), remounting the carb, battling the vacuum hose from the carb to the dashpot . . .
It starts.
So, running insanely roughly, I backed it into the driveway to fill the radiator . . . which seems to be leaking from the new water pump, but that's another thread . . .
thanks, folks.
And hopefully Mr. Google ranks this thread highly enough to save someone else the hours, fumes, and skin . . .
If you are running a sinterd bronze filter in the carby, it could be blocked.
The only way to test one of these is, I have found, to simply "huff" breath through it. If the air doesn't freely flow through it, then it is blocked, and due for a replacement.
This filter is a last gasp method of filtering fuel, and in a lot of cases, mechanics omit these, and just rely on the filter in the fuel pump.
And, in a lot of cases, mechanics don't even realise that there is a filter in the Cadillac fuel pumps, as none of the Chevrolet lines have filters in their fuel pumps.
Bruce. >:D
It's a rippled paper with brass looking ends on mine, one of which has a hole. I think it's a #3014.
Put the solid end pointed out in the carb, and it blocks the flow entirely . . .
hawk