Intake manifold overflowing problem after installing Weber. HELP!

[IrvinM]

I have a 1975 Datsun 620 with the L20B engine and a Weber 32/36 electronic choke carburetor.

 

I just finished installing my Weber carburetor and I noticed my gaskets were leaking fuel. I moved the throttle on the carburetor about 100 times while trying to adapt a throttle cable, and since everything was hooked up the vacuum inside of the carburetor was pulling fuel into the carburetor, into the intake manifold. I moved the throttle linkage to check how far would it go, why was it getting stuck, what everything else looked like when the throttle was wide open, etc. This pulled fuel in every time, so my intake got flooded, and my gaskets are leaking.

 

The gaskets leaking are the bottom one where the intake and the exhaust touch, and the gaskets on the carburetor adapter plates.

 

I also put some blue locktite on my carburetor studs to make sure they would not walk out with vibration and stuff... bad idea. They are STUCK! Now I can't tighten any bolts because my studs are stuck, and my carburetor won't slide off. The studs seem to be tilted slightly, so my carburetor won't slide off the four bottom studs.

 

Now, would it be normal to have fuel leaking from the intake if it is flooded? Would it be normal to have fuel leaking from the carburetor plate gaskets if they were flooded? Note that I never turned on the truck when playing with the throttle.

 

PLEASE HELP!

 

Here are some pictures:

 

Please look at the gasket right below the carburetor's printed information. This first gasket and the one below it are the ones leaking, not the third one.

 

 

 

 

Here you can see a small portion of the gasket that is in between the intake and the exhaust. This one is leaking too.

 

HELP PLEASE!!!

[620Turbo4X4]

Yeah. Those adapters suck. That why I used a one piece adapter. The paper gaskets will seep some if soaked with fuel, but it looks like yours are really leaking.

 

Did you file the adapter surfaces flat?

 

That lower gasket is going to be a problem. You shouldn't be leaking any fuel there. That's a definite indication of a vacuum leak and will need to be fixed too. Start spraying the bolts now with some penetrating oil and hope they don't break when you take them out... or s can it and look for a separated intake/exhaust manifold setup.

 

The best way to remove studs are to double nut them. put two nuts on the stud and tighten them against each other tightly, then use the lower nut to remove the stud.

[wayno]

If this is a brand new carb that has never been run, how can it even have gas in it at all, do you have an electric fuel pump?

It doesn't even look like the fuel hose is hooked up, something else is going on here.

Maybe it is a water leak???

[IrvinM]

If this is a brand new carb that has never been run, how can it even have gas in it at all, do you have an electric fuel pump?

It doesn't even look like the fuel hose is hooked up, something else is going on here.

Maybe it is a water leak???

I did hook up the carburetor to a fuel line and turned on the truck. I didn't have a throttle cable at the time so today I went to the junk yard and found one. I rigged it and installed it, but I was moving the throttle cable back and forth, so this poured a lot of fuel in there and it has been sitting there for a while (like 9 hours). So for a long time I did not turn on the truck. Next thing I notice is my gaskets soaked in fuel. So I was trying to remove the studs but they are seized because I put some blue locktite in there. My carburetor will not come out straight up because I'm assuming the studs are slightly angled, so they are locking in the carburetor. I can only remove the studs to remove the carburetor. Oh, and my fuel pump is mechanical.

[IrvinM]

Yeah. Those adapters suck. That why I used a one piece adapter. The paper gaskets will seep some if soaked with fuel, but it looks like yours are really leaking.

 

Did you file the adapter surfaces flat?

 

That lower gasket is going to be a problem. You shouldn't be leaking any fuel there. That's a definite indication of a vacuum leak and will need to be fixed too. Start spraying the bolts now with some penetrating oil and hope they don't break when you take them out... or s can it and look for a separated intake/exhaust manifold setup.

Do you still have the old metal fuel line?

 

It's a good idea to keep it and use the fuel return line feature of it if possible.

 

The best way to remove studs are to double nut them. put two nuts on the stud and tighten them against each other tightly, then use the lower nut to remove the stud.

The picture does show badly soaked gaskets but its not dripping fuel anywhere. I don't know if the fuel slowly creeped in there or if its possible to have fuel and oil mixed and leaking through the gaskets. The fuel stain has a very faint smell of fuel, and it hasn't gone away. It has been at least 4 hours and the wet stain is still there. The plate adapter gaskets have a stronger smell of fuel.

[wayno]

I did hook up the carburetor to a fuel line and turned on the truck. I didn't have a throttle cable at the time so today I went to the junk yard and found one. I rigged it and installed it, but I was moving the throttle cable back and forth, so this poured a lot of fuel in there and it has been sitting there for a while (like 9 hours). So for a long time I did not turn on the truck. Next thing I notice is my gaskets soaked in fuel. So I was trying to remove the studs but they are seized because I put some blue locktite in there. My carburetor will not come out straight up because I'm assuming the studs are slightly angled, so they are locking in the carburetor. I can only remove the studs to remove the carburetor. Oh, and my fuel pump is mechanical.

 

 

The only way that fuel can be in the carb is if you started it, or tried to start it with the fuel line connected.

Sometimes the studs are so tight on the sides of the holes of the carb, that it is hard to remove the carb, or for that matter to install it either, so far I have observed that weber carbs and adapters are not made with a high degree of accuracy, their tolerances/quality control are dubious at best, otherwise things would just drop on, but they don't, at least not the ones I have dealt with, it's hard to get them on there tight, when they don't even fit on the studs properly.

[620Turbo4X4]

The picture does show badly soaked gaskets but its not dripping fuel anywhere. I don't know if the fuel slowly creeped in there or if its possible to have fuel and oil mixed and leaking through the gaskets. The fuel stain has a very faint smell of fuel, and it hasn't gone away. It has been at least 4 hours and the wet stain is still there. The plate adapter gaskets have a stronger smell of fuel.

I would try to fix the leaks if possible. Give the thing a good yank or try the double nut technique on the studs easiest to get to. That much fuel is not all over the place is not normal even if your carb were leaking fuel into your engine.

[datzenmike]

Fire it up and run it. Pull plugs and crank it to 'dry' the cylinders if you have to. Excess fuel will burn off and then you can decide if the gaskets are 'leaking'.

[IrvinM]

How much torque can I put on the nut that goes on the studs? whats the maximum that it would take? and if I get to remove the carburetor, how much torque should I apply to the other bolts below it?

[620Turbo4X4]

How much torque can I put on the nut that goes on the studs? whats the maximum that it would take? and if I get to remove the carburetor, how much torque should I apply to the other bolts below it?

Not much. It would be measured in in-lbs of torque… Not ft-lbs. The adapters are made from really cheap aluminum and will strip the threads out if tightened too much.

 

One thing that should have been mentioned in your prior adapter question post is that lock-tight begins to harden as soon as you start threading the bolts in. So once you start putting things together with the stuff, the bolts need to be tightened down to where you want it them relatively quickly before the stuff hardens (which can be in as little as 20-30 seconds… or less). If you don't, you have no idea exactly how tight the fastener really is because the threads are locked in place with the stuff...

[Sealik]

 

 

What type of 'Locktite' did you use?...there are varying 'strengths' available.

I use Permatex Threadlocker Red........never had any issues removing a nut and or.

 

You should be able to work the carb off.... one side at a time....bit by bit.

[IrvinM]

I think I got it solved! now it is just the choke that is choking my truck. Maybe that is why they called it that? I have an electronic choke and I have no idea where it goes.

 

My truck turns on and I've seen no dripping so far. I removed the nuts from the carburetor studs and took the locktite off. I put them back on (since I can't easily remove the studs, therefore the carburetor is stuck). I tightened them a little bit more than I did the first time and BAAAAAMMMMM!!!! The gaskets don't seem to leak no more.

 

If necessary, I will remove the valve cover to gain easy access to the studs on the carb closer to the valve cover. For now, I turned it on for like 10 minutes and looks OK.

 

Does anybody know where to connect the electronic choke to? Some crazy guy at the wrecking yard told me to connect it directly to the 12 Volt battery post. Isn't this going to draw power from the battery 24/7?

 

Thanks everybody. I feel good being part of this very helpful community :-)

[IrvinM]

The choke is on the carburetor, installed and everything but I don't know where to plug it to.

[datzenmike]

There will be two wires going to the carb. A RED wire for the idle cut solenoid and a Blue wire for the choke heater. Both wires come from the driver's side inner fender from near the coil area. They clip to the driver's side of the stock carb and wrap around the back of the carb.

 

If you can't find the Blue wire you can splice the choke heater into the Red idle cut solenoid and this will work. The red wire only has power when the ignition key is ON.

[Taz]

tbh if your engine is running well you shouldnt need a choke if you let it warm up a little before you drive off. Its a good idea to warm your engine for a minute or two anyway, because it makes the oil flow better.

[IrvinM]

Yeah but my carburetor is still under the Weber warranty. If I mess around with it I might void the warranty.

[banzai510(hainz)]

Does anybody know where to connect the electronic choke to? Some crazy guy at the wrecking yard told me to connect it directly to the 12 Volt battery post. Isn't this going to draw power from the battery 24/7?

 

 

Yes.24/7 he wants you back

thats why hes working at the wrecking yard!!!!!!!!!!

 

read what mike said the wires are there already

[IrvinM]

Found it! Found that red wire that outputs a 12V difference once the ignition key is turned! Now to the vacuum lines! :)

 

Thanks everyone!

[datzenmike]

[Stoffregen Motorsports]

How much torque can I put on the nut that goes on the studs? whats the maximum that it would take? and if I get to remove the carburetor, how much torque should I apply to the other bolts below it?

8mm bolts/studs usually take 12 to 15 pounds of torque, 20 in extreme cases.

 

12 pounds of torque is basically finger tight plus 3/4 of a turn. Not much at all.