• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Today's Weird Question

Share this page

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Only one answer stuck needle valves.[/QUOTE]

no needles - Grose jets!
 
Ok stuck grose jets. What ever, the fuel is not getting through from the line to the carb. Remove, squirt with Carb cleaner replace, go for a drive.
 
FWIW, I have seen Grose Jets stick, quite easily, when they have been dried out and the evaporated fuel leaves a residue. Has usually happened when I have had the carbs apart for some reason but has also happened after long storage periods. Though my experience has usually seen them stick open and overflow the float bowls. Once unstuck, no more problems during normal operation.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]the supply tube from the bowl to the jet is obviously open.[/QUOTE]

Both carbs at the same time? Hard to believe!


I finally got the bowls to fill by doing what Jack suggested (actually, I soaked the Grose jets in cleaner) & in the process of removing the carbs to check the jet supply tubes from bowls to carb bodies to make sure they weren't clogged (they weren't), I broke one of the jet supply tubes...so, I replaced it with a good used jet; however....

...with fuel flowing into the bowls & from them into the carbs themselves, the carbs will only run with starter fluid - not with gas! So, even though I had put 2-1/2 gallons of fresh gas in the tank when I started this ordeal, I'm draining it out right now as I type & will try some more new gas from a different station!

I also checked the plugs while I was going through everything & only #3 was moist (not much though) - so, I'm not flooding her.

...this is just strange! If it were old gas, I could believe things were gummed up blocking its flow & the gas wasn't good enough to 'ignite'...however, I drained the system before I parked it last year, fogged everything, & added new gas this year. So...........
 
Exactly. If fuel pumps out the hose when disconnected from the carb, and the engine runs off the float bowls, then the problem is between the end of the inlet hose and the bowl itself. there is only one part there, and it is the float valve. There must be a blockage somewhere.
 
tony barnhill said:
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]the supply tube from the bowl to the jet is obviously open.
Click to expand...

Both carbs at the same time? Hard to believe!


[/QUOTE]

Tony, I meant that the jet tubes were unobstructed, and not the root cause of the problem.
Jeff
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Tony, I meant that the jet tubes were unobstructed, and not the root cause of the problem.[/QUOTE]


Jet tubes are unobstructed.....

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]then the problem is between the end of the inlet hose and the bowl itself. there is only one part there, and it is the float valve. There must be a blockage somewhere. [/QUOTE]

Nope, no blockage...I've had everything apart & cleaned & blown carb cleaner through everything!
 
Are you getting enough pressure from your pump?
Can you put your thumb over the fuel line and easily block the flow?
Maybe it flows with zero back pressure but when you connect it up it stops.
Just a guess. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif Hope you figure this out!
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Are you getting enough pressure from your pump?
Can you put your thumb over the fuel line and easily block the flow?
Maybe it flows with zero back pressure but when you connect it up it stops.[/QUOTE]

4psi pressure...bowls are now filling & staying full

However, the car will only start & run when starting fluid or carb cleaner is sprayed inside carbs - choke engaged or not.

I give up! Tomorrow I'm pulling the carbs again & will disassemble, clean, & rebuild both - top to bottom!

....& I'll never ever fog an engine at the end of the driving season again!

...only thing I can figure is there's something keeping the gas from getting from the carbs into the intake manifold or something is clogging/coating the needles but I can't see it or determine how its blocking the flow of gas....from both carbs!
 
Are you SURE the float valves are functioning properly? If they are bent, they may bind when trying to open naturally even though the operate by hand freely. Do you have a set that are known to work that you can test in the car? Only take a few minutes to swap the lids out from another set of carbs from a running car, and then you can write the valves off for good.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Are you SURE the float valves are functioning properly? If they are bent, they may bind when trying to open naturally even though the operate by hand freely.[/QUOTE]

Can't see any problem with them - fuel is now holding at the proper level in the bowl....don't know how they could both go bad from just sitting over the weekend.

Don't see how they could go bad just sitting over the winter!
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Sounds like its time to check the ignition.[/QUOTE]

It'll run forever so long as I spray starter fluid in the carbs.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]fuel is now holding at the proper level in the bowl[/QUOTE]
Wait, so now the bowls are staying full?
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Wait, so now the bowls are staying full? [/QUOTE]

Yep, I took the bowl tops apart (floats off, Grose jets out) & soaked the Grose jets in carb cleaner....now the bowls stay at proper levels of fuel

took the jets off & blew carb cleaner through them - supply tubes are not plugged so fuel is flowing into carb body

Needle is centered & all adjustments are just like they were in the Fall when I laid the car up (when it was running great!)
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]...but it still doesn't run? Or are you saying something fixed it? [/QUOTE]

Still doesn't run unless I spray starter fluid in the carbs.
 
If it ran when you manually filled the float bowls, then you can rule out everything except the float lid. It could be a clogged vent tube, but if I'm a betting man, I say file 13 those grose jets and put some needle and seats in it and you will cure the problem. All I use is Curto's viton tipped needle and seats, any time I see a grose jet, it goes straight to the garbage can.
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]If it ran when you manually filled the float bowls,[/QUOTE]

Only ran with me spraying starter fluid in it! Never ran on its own accord.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I say file 13 those grose jets [/QUOTE]

Grose jets are allowing gas in the bowls - but I can't tell if the gas is getting to the plugs....starter fluid does though....this is the weirdest thing!

& why, after sitting all winter, did they both just up & quit?
 
Back
Top