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Cal-look/High Performance => Cal-look => Topic started by: Diederick/DVK on April 07, 2013, 19:56:22 pm



Title: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 07, 2013, 19:56:22 pm
To all willing to drop in their 2 cents:

Due to circumstances I had to rebuild my engine again over the winter with all new bearings. The car is still suspended and I can't drive yet but I've just got round to firing her up again last week. And today after some tweaking, my problems remain!

The engine revs fine and all seems good. The engine ran before so there shouldn't be a reason that won't work. But, to cut to the chase, I have fuel dripping from under the #4 combustion chamber. When I rev the engine up I get a bit of splatter on the ground and on the header. There's also a small drop of fuel that came from the header and muffler gasket and some initial splatter from the exhaust. Soon enough I shut the engine off, cause this just isn't right and moreover potentially dangerous.

What I have checked so far is that the #4 plug, which is new, has a slightly black liquid electrode already.
The #4 chamber appears to be full. Yet, the engine doesn't appear to leak when it's shut off.
The IDAs are good, fuel pressure is a steady 3 psi and jetting is in the ballpark.
Also, the ignition appears to be working. The Magneto is at 28 degrees and the engine revs like a fierce barking dog.

I am in dire straits since one of my good friends is to use my '67 for his wedding in 19 days time.
Since he asked I put a lot of money into the car and I'd be heartbroken if I'd have to pull out!


Title: Re: In dire straits, #4 fuel leak
Post by: nicolas on April 07, 2013, 20:09:16 pm
i would look at the carbs, seems to me one is spilling fuel. the fuel can't be burned completely and therefore goes in the header and the exhaust.


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 07, 2013, 20:17:45 pm
Thanks Nicolas. I get what you mean but there's no fuel leaking from the carbs or intake as far as I can see. The fuel drip is only visible underneath the car.
It also seems it comes from the ribs of the head somewhere, so that's a bit more inward...


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 07, 2013, 20:44:17 pm
Hard to shoot a sharp pic but what you see are the #4 pushrod tubes and the leak above it.


Title: Re: In dire straits, #4 fuel leak
Post by: TexasTom on April 07, 2013, 21:07:45 pm
I know you said the #4 plug is new ... what is the gap? Remember, mags like small gaps, like say .018 to .020"!
Also, have you checked that there is good spark at the plug on #4? If there's fuel unburned and no leaks, no spark? or POOR spark ... ?
Let's get this thing FIXED, Diederick!

TxT


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 07, 2013, 21:19:44 pm
Tom, I replaced all plugs with new BP7ES that I gapped at .018" and that solved the faulty ignition issue of last weekend.
Ignition seems good now listening to the engine. How should I best check whether I have good spark?
I can't imagine I have a combustion leak, but I suppose I could hook up a compression meter and quickly compare #4 and #2?!

Thanks again, Tom!


Title: Re: In dire straits, #4 fuel leak
Post by: Type1/DVK on April 07, 2013, 21:20:20 pm
I've done some brainstorming about and to me it seems to be a leaking #4 intake on the ida or somewhat spilling/bleeding on that channel. After that when the combustion chamber is full of liquid/gasoline it will hydropress those liquids out of the chamber (around the barrel) and onto your tubes.. but that is just a brainstorm  ??? ::)

Compression numbers on that #4 are good? what about leaving the plug out and cranking the engine, if it spitting liquids you know your chamber is if somewhat full of gasoline. Plug gap also good?


Title: Re: In dire straits, #4 fuel leak
Post by: TexasTom on April 07, 2013, 22:30:20 pm
Let us know what you find on the compression and/or spark tests, Diederick!


Title: Re: In dire straits, #4 fuel leak
Post by: Zach Gomulka on April 07, 2013, 22:46:27 pm
Swap the carbs from side to side. No need to hook up linkage, just fire it up and rev it a bit with your hands. If the problem moves from 4 to 1, you know the problem is in the carb. If it doesn't move, then you've at least eliminated one factor.

Float level too high?


Title: Re: In dire straits, #4 fuel leak
Post by: jaqo on April 08, 2013, 15:06:49 pm
Had a similar problem caused by - well known problem for ida- fuel squirter (acc. pump) leaking fuel.


Title: Re: In dire straits, #4 fuel leak
Post by: Fastbrit on April 08, 2013, 17:07:00 pm
Float level too high
Main jet loose (or the whole jet stack – happened to me on the rolling road, and wiped out the rings on one cylinder inside 20 minutes due to excess fuel)
Leaking accelerator pump
Poor head/barrel seal


Title: Re: In dire straits, #4 fuel leak
Post by: Zach Gomulka on April 08, 2013, 17:08:39 pm
Faulty needle/seat?

Swap the carbs, it's easy!


Title: Re: In dire straits, #4 fuel leak
Post by: Jim Ratto on April 08, 2013, 19:49:04 pm
Is your fuel line TEE anywhere near the fan opening on front of fan housing?


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 08, 2013, 21:04:24 pm
Thanks for the replies. The TEE is the Holley regulator underneath the deck lid spring.
I'll check the carburettor suggestions this Friday. But how do I find out if the accelerator pump is faulty?


Title: Re: In dire straits, #4 fuel leak
Post by: danny gabbard on April 08, 2013, 22:56:56 pm
Whats your fuel presure ?


Title: Re: In dire straits, #4 fuel leak
Post by: Jim Ratto on April 08, 2013, 23:21:14 pm
turn fuel pump on (don't start car) and let it run 20-30 seconds, and leave it on. Get a mirror and look down #3/4 throats, see if you see fuel spilling over onto butterflies. If your fuel pressure is 3.0 it's not too high. You either have a defective float, a defective or loose needle valve or your float level is off. I just had a needle valve go haywire in my 1/2 carb and flooded engine over badly. Luckily I was in my garage.


Title: Re: In dire straits, #4 fuel leak
Post by: Lanny Hussey on April 08, 2013, 23:56:20 pm
I had an IDA float with a pinhole in it. It only held a few tablespoons of fuel but really caused mayhem.


Title: Re: In dire straits, #4 fuel leak
Post by: Zach Gomulka on April 09, 2013, 02:35:06 am
turn fuel pump on (don't start car) and let it run 20-30 seconds, and leave it on. Get a mirror and look down #3/4 throats, see if you see fuel spilling over onto butterflies. If your fuel pressure is 3.0 it's not too high. You either have a defective float, a defective or loose needle valve or your float level is off.

X2!!!


Title: Re: In dire straits, #4 fuel leak
Post by: jaqo on April 09, 2013, 11:56:25 am
Thanks for the replies. The TEE is the Holley regulator underneath the deck lid spring.
I'll check the carburettor suggestions this Friday. But how do I find out if the accelerator pump is faulty?
In my case I just looked inside at the carb barrel while the engine was running and I could see the fuel dripping.


Title: Re: In dire straits, #4 fuel leak
Post by: wolfswest on April 09, 2013, 12:30:38 pm
Thanks for the replies. The TEE is the Holley regulator underneath the deck lid spring.
I'll check the carburettor suggestions this Friday. But how do I find out if the accelerator pump is faulty?
In my case I just looked inside at the carb barrel while the engine was running and I could see the fuel dripping.

X2: I also had this once, took the carb apart, cleaned and greased some parts and everything was A okay after firing up the engine again.


Title: Re: In dire straits, #4 fuel leak
Post by: Type1/DVK on April 12, 2013, 23:48:11 pm
any news?  ;D


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on April 13, 2013, 14:09:49 pm
I got to spend a little time on it today. Took the carbs apart and set the floats, which were way off, replaced and set the needle valves, checked the jet stacks.
Then, once I put everything back I turned the fuel pump on and all seemed well as far as the absence of fuel spillage. Fired up the engine and after a few seconds the leak started again.

Ran out of time, so that's it for today again...


Title: Re: In dire straits, #4 fuel leak
Post by: Jesse/DVK on April 13, 2013, 21:13:16 pm
You need to close your butterflies more. This is normal (got is also a bit with a cold engine) the pulses of the engine make te butterflies vibrate what triggers the accel pump.


Title: Re: In dire straits, #4 fuel leak
Post by: jaqo on April 14, 2013, 00:15:35 am
Disable the acc. pump and check again.


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on June 17, 2013, 20:37:35 pm
Just when I thought I had it sorted. Now I'm really lost at it.

What I recently did is:
- Replace the floats, needle valves, gaskets and a few jets and set everything within factory weber specs.
- I replaced my Facet fuel pump with a self-regulating lower output rotary pump.

I finally had time to install everything today. And what I have now is an overflowing carburetor with the fuel pump on and engine off. Fuel is gushing from the jet screen in between the velocity stacks, pouring into the venturies through the pump jets and there's a pool of fuel underneath the #3-#4 side. It has always been the same IDA, new everything did not help. Now I don't even want to think what this is doing to the engine in terms of bore wash and my sump gaskets that have already started to leak oil.

I'm open to suggestions, please.


Title: Re: In dire straits, #4 fuel leak
Post by: Zach Gomulka on June 17, 2013, 21:48:32 pm
You have swapped the carburetors side to side and the problem followed?

Try swapping the carb tops and see what happens. It's a process of elimination, dude ;)


Title: Re: In dire straits, #4 fuel leak
Post by: Taylor on June 17, 2013, 22:26:42 pm
What needle and seat do you have?? 


Title: Re: In dire straits, #4 fuel leak
Post by: gizago on June 17, 2013, 22:53:05 pm
Float bowl damaged or cracked and leaking into carb body/ Venturi?


Title: Re: In dire straits, #4 fuel leak
Post by: Lids on June 17, 2013, 22:57:42 pm
run it with some 48 DRLA's, and then send the IDAs to someone to look at


Title: Re: In dire straits, #4 fuel leak
Post by: peejke on June 17, 2013, 23:03:11 pm
NO sollution, but as far as the ignition part goes, dump the BP7ES plugs. They can't stand a rich mixture. Probably gone allready.


Title: Re: In dire straits, #4 fuel leak
Post by: deano on June 17, 2013, 23:20:36 pm
It may related to the accelerator pump lever underneath. In some cases, due to the position of the lever and roller (on the throttle shaft), it maybe high enough on the cam lobe to allow pressure to be applied to the pump rod, which then caused it to push raw fuel into the venturi. Berg made an adjustable cam lever to fix this problem. Usually, it is caused by the butterflies/shaft being open too much, which places the roller too high on the lever cam lobe. Make sense? Hope so.


Title: Re: In dire straits, #4 fuel leak
Post by: BeetleBug on June 18, 2013, 06:24:30 am
I would also check the oil. My guess is that it is flooded with gasoline. If your carb cant shut off the fuel it will continue pooring fuel down your intake channel and continue up the manifold causing the leak between the manifold and the head. It is a good thing that you noticed this now and not on the road, been there - done that.

Best rgs
BB


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on June 18, 2013, 15:58:41 pm
Fixed it. It appeared that the extra tang on the new float (which serves no purpose IMO) hit the needle valve so that the proper tab couldn't close off the ball in the needle valve. Bend the tang and all is good now. The carbs stayed dry and the engine ran. So I dumped the oil. The fuel may however have deteriorated some gaskets. Bummer! So much for a clean engine...

Anyway, thanks for the suggestions. Much appreciated!


Title: Re: In dire straits, #4 fuel leak
Post by: Zach Gomulka on June 18, 2013, 16:49:15 pm
YEAH!!


Title: Re: In dire straits, #4 fuel leak
Post by: deano on June 18, 2013, 21:32:29 pm
I've also had a pair of IDAs that were badly worn, in which the accelerator pump rod bushings were worn (too much sand rail use), causing them to leak and stick! Had to re-size them to fix the problem.


Title: Re: In dire straits, #4 fuel leak
Post by: Jesse/DVK on June 18, 2013, 21:58:43 pm
Let's finish this beetle this Sunday and take it for a spin Died!


Title: Re: In dire straits, #4 fuel leak
Post by: Diederick/DVK on June 19, 2013, 15:31:48 pm
LIKE