Weber 32/36 Carb Help

[beamdream]

Just to help clarify a few things:

It's not a Pinto manifold. Almost surely it is a manifold from a SIV. It is quite common to use these SIV manifolds with Webers. The SIV had a similar 2 barrel (Solex) carb. But as noted, it typicaly requires a slight mod to the throat to match the Weber.

Also I went back at earlier posts to verify you have a 1725. You said the block has number B395016xxx. And you thought that meant "early" production. I do not see any implications for your present issues, but know that this is not an "early" block. It's more than 3/4 thru production, somewhere in June-Aug 1967.

Lastly , someone else suggested looking for manifold leaks, mainly at the block or possibly at the carb / manifold joint. As far as I can see such a leak would be the only way to account for the pooling of gas in the manifold.

Maybe the backfiring has blown the intake manifold gasket.

Tom

Folks it is highly unlikely that any automotive fuel pump (unless high volume electric) is going to have enough output to flood the engine at cranking speeds, most pumps run at 4-6psi and carb floats are designed to hold closed against this.

Manifold leaks will give lean mixtures not the other way round, by the way lean mixtures, wrong ignition timing and leaking valves will give you a backfire, but lets concentrate on the basics.

I would concentrate first on the carb, why, well the fact that it fires and attempts to run is enough of an indication that the ignition system is at least functional, whats not clear is why the engine is flooding with fuel; even with a poor ignition system the engine should not flood.

So can I suggest that you start by taking the plugs out, remove the coil wire, foot flat to the floor and crank the engine over for at least 10 seconds, this should clear any residual fuel from the manifold and cylinders; clean plugs and replace, refit the coil wire.

Now foot flat to the floor and keep it there, crank the engine and if it fires keep it running if you can, easing your foot back and see if you can keep it going, if it dies switch off and pull the plugs. Presuming it has flooded, even at high throttle settings the plugs will be black and sooty, and whilst its running you will see rich black smoke from the exhaust; just another thought, do this with the air cleaner removed.

Moving forward will depend on the outcome of the above.

 

[RootesRacer]

I wonder where many of you get your information, its kind of scary...

Most larger carbs like 4bbls and larger 2bbls (half a 4bbls like a holley 2300) are designed for 4 to 6 psi as they require the higher pressure in order to deliver the volume of fuel without huge fuel lines.

Smaller 2bbl and 1bbl carbs are designed to run between 1.5 and 3psi typical.

Even high performance DCO, IDA, IDF webers ETC typically run no higher than 3psi operating and 4.5psi static max. The needle and seat is a tuning part and can be set to take higher pressure by going with a needle and smaller seat orifice.

Every time I hear someone tell me that they have fuel pooling the intake, the first question I ask is do you have an electric fuel pump. The second is, what is your static fuel pressure?
When you buy most electric fuel pumps, are unregulated and they tell you a range of pressures, but the seldom tell what the pressure will be pumping dead head, which often is double or more what the "at flow" value is.

When the engine is not running and the needle and seat cannot halt the flow fuel due to excess pressure, only a very small flow past the needle and seat will cause bowl overflow. A condition that often wont occur with the engine running as the engine can consume the leakage flow.

Something to think about.

 

[mferris]

Now things are getting interesting on the forum!

I'll take a few hours tomorrow to distinctly walk through some of the discrete steps below to start isolating at least a few variables. Starting with the coil and then fuel pressure, manifold leak and I'll see where it goes from there.

I certainly agree that there cannot be too much going on here, this is my first serious engine work but it does seem very simple (which is why I got this car to learn on).

The only other wild idea I had is whether the cam shaft has been replaced with one that has a different firing order. Other than the painted block - I have no idea what they did nor if it is even possible to have a cam with a non-standard order for this block. I have confirmed that the current order is what is in the WSM. However, while illegible, someone had written another order in the WSM and then scratched it out.

 

[RootesRich]

The only other wild idea I had is whether the cam shaft has been replaced with one that has a different firing order. Other than the painted block - I have no idea what they did nor if it is even possible to have a cam with a non-standard order for this block. I have confirmed that the current order is what is in the WSM. However, while illegible, someone had written another order in the WSM and then scratched it out.

Mike, not even a remote possibility. No cam will change the firing order from the WSM.

Re-read Jarrid's (aka RootesRacer) post. He's right on the money.

 

[Tom H]

Mike, not even a remote possibility. No cam will change the firing order from the WSM.

Rich, I'd say "highly unlikely", especially since Mike's car ran for 10 minutes with this cam (and I assume same wiring).

But if Mike has changed the wiring order since it ran then it's possible, maybe even likely (if he has changed the wiring) . I cannot imagine someone making a custom cam for this car, but it IS possible to create a cam that would make the firing order 1 2 4 3. (swapping the ex /int sequence of #2 and #3)
. Or am I missing something that makes this impossible?

But I think this is mostly just theoretical discussions - UNLESS Mike has changed wiring order since the car ran.


Tom

 

[mferris]

So Mike certainly didn't intend to change the wiring order - but at this point all I can say is that it is in the proper WSM order and I certainly don't recall switching it from when I got it.

I'll keep firing order for a very very last resort.

 

[RootesRich]

So Mike certainly didn't intend to change the wiring order - but at this point all I can say is that it is in the proper WSM order and I certainly don't recall switching it from when I got it.

I'll keep firing order for a very very last resort.

Mike, If you'd like send me a PM and I'll give you my cell phone number. I'm happy to discuss your non-start situation over the phone.

 

[agmason54]

Weber carb help

M F
Did you check to see if the distributor has jumped out of it's base? That would explain why it ran for 10 minutes and then quit.
This is a rule I was taught by old school mechanics-

90% OF CARB PROBLEMS ARE (due to) IGNITION!!!!!!!!!!

In other words the ignition system is the prime suspect and the carb is usually not to blame

Al

 

[mferris]

Nothing yet

So far today, done in discrete steps

Video of flooded intake: http://youtu.be/SNOwI6lUDh4
Picture attached.

What we've done:

1) Removed plugs and cranked to attempt to clear out intake of pooling - didn't really do much

2) kept accelerator to the floor (no pumping) - and cranked with and w/o choke set - it would catch for 4-10 cylinder fires, but would not run.

3) Rechecked 6deg BTDC static timing - no difference

4) new coil - no difference.

5) cleaned spark plugs - no difference

6) measured static fuel pressure (~4psi) and "cranking" (since it won't run) 3.5psi

7) took off carb, then soaked up about 1/2 dripping shop rag of gas out of intake, then plugged fuel line an ran without, then with a gravity feed - no difference.

I'll check that a backfire has not pushed up the distributor.

At this point - I don't see how it is the fuel considered we attempted it with a manual feed.

 

[John W]

....someone else suggested looking for manifold leaks, mainly at the block or possibly at the carb / manifold joint. As far as I can see such a leak would be the only way to account for the pooling of gas in the manifold.

Maybe the backfiring has blown the intake manifold gasket.

Tom

My SIV with webber is down right now with this exact same problem. Runs wide open for about 5 minutes then dies and floods the intake with gas. Ran perfect before I removed the intake and exhaust and exchanged gaskets.

 

[Bill Blue]

Yeah, that was indeed, flooded.

Mike, you said "no difference". Could you describe exactly what happened as you were running it with gravity feed? Sometimes it takes a long time to work all the excess fuel out of the intake system. I'd continue trying to run it with no gas in the carb until it will not fire, then try manual feed.

Bill

 

[jumpinjan]

I watched the video clip, and oh-my, its droned in gas like Bill said.
You got to dry it out good, including the plugs (or get new plugs just to get it started, and put the others back in later).
Check your oil now, there's a possible risk of it diluted with gas.
Get the carb bowl empty too (just remove it and turn it up side down in a pan). Put it back together and try starting with a prime of gas in the carb (don't flood it again with too much prime). It should run on the prime.
Jan

 

[Tom H]

Wow, that looks like quite a pool of gas. I assume the sloshng is due to cranking the starter.

Did the pool reappear after cranking with pedal to the floor?

Couple other thoughts:

1) Looking back at both threads, I do not see you say you changed dist cap. I see you ordered one, but never said you replaced it. Did you replace it?

2) It seems to me that the car has not run since you replaced the wires.
Time to double check the wire order. and other stuff. I've seen this mess people up. Firing order is 1-3-4 -2 . # 1 cyl is at the front of the block. . Wire #1 should come out of the dist cap near the 12 O clock position, closest to the block. The rotor rotates counter clockwise , so next wire (approx 9 oclock pos) goes to #3 , next ccw is #4 and last, near 3 O Clock, is #2.

Tom

 

[mferris]

Eureka

I don't know what worked. I don't know when it worked. I don't know how it worked. But it starts and runs now.

I tweaked the static timing again and opened the points - and with some coaxing it started. I went back to the original condensor - but have a new coil, new points, etc.

While cold - it would bog down and backfire (about 3 times total), but once warmed it ran relatively well, idling around 1400rpm (which I know is high).

Thanks to BullDurham for dropping by and pointing out further refinements with the mechanical throttle linkage that might need to get adjusted (i.e. I need a return spring to pull down the throttle to idle and do a few other things).

I'm almost positive that it was electrical - but the new carb will most likely helped regardless so I'm happy.

After running for a while - the pool of gas was gone - so I'll check it over the next few weeks and see if it returns in any significant form.

Thanks all!

 

[Bill Blue]

I don't know what worked. I don't know when it worked. I don't know how it worked. But it starts and runs now.

Thanks all!

Mike, I don't know how many times that has happened to me. An issue arises, I beat my head against a wall for a few days, the issue finally goes away and I have no idea just exactly what the problem had been.

Welcome to the club.

Bill

 

[agmason54]

MF
I think you are missing something simple like maybe a bad rotor and cap like Tom H mentioned.Too bad you can't bolt on a complete known running distributor and coil. I never leave home without them.
I broke down once due to a bad rotor.I replaced everything but the rotor with no luck.After I finally installed a new rotor my car ran fine.I reinstalled the old rotor to prove that the rotor was indeed bad. It looked perfect but the car refused to run on it.
I think you have compound problems but there are only two thing s that make it run -FUEL and SPARK some how you got both way out of whack.
I would start fresh with an oil change,put fuel to the carb on the bench and see what it does when you work it.Does it pee gas on it's own?It may have a sunk float or maybe no float needle..who knows?
Next I would renew the cap and rotor and make sure of your firing order.1342
A backfire will not make the distributor jump out but you may have enough gas in the crankcase now to make the engine jump out of the car it lit off.
You have all the clues I can think of-You are lucky to have so much help.When I breakdown in BF Egypt all I have is gray matter, tools, known running distributor,coil and fuel pump.
Good luck
Agm

 

[mferris]

Now that it starts - I'm going to isolate this backfiring issue next (later in the week).

It certainly has a fast idle (which I believe is due to throttle linkage and lack of a idle return spring), but when I accelerate under light to moderate load there are soft backfires coming out of the carb (not the tailpipe).

I am presuming this is from excessive fuel getting into the intake (3.5-4psi may be too much) and some timing tweaks needed (which I presume means I need more vacuum advance as it occurs as I attempt to accelerate??)

I have a (cheapo) regulator that I got to see if I can dial it down to 1-2psi.

From there I'll figure out fine tuning on the timing. I'm presuming there is no magic, other than tweak is A/R until it just runs "right" and idles well.

Thats about a total of 14 hours on the car in the past 3 days. I think I'm getting my money's worth.

 

[jumpinjan]

I don't know what worked. I don't know when it worked. I don't know how it worked. But it starts and runs now.

Well, thats good its running, but you really need to understand the cause of that flooding problem.

 

[beamdream]

I don't know what worked. I don't know when it worked. I don't know how it worked. But it starts and runs now.

I tweaked the static timing again and opened the points - and with some coaxing it started. I went back to the original condensor - but have a new coil, new points, etc.

While cold - it would bog down and backfire (about 3 times total), but once warmed it ran relatively well, idling around 1400rpm (which I know is high).

Thanks to BullDurham for dropping by and pointing out further refinements with the mechanical throttle linkage that might need to get adjusted (i.e. I need a return spring to pull down the throttle to idle and do a few other things).

I'm almost positive that it was electrical - but the new carb will most likely helped regardless so I'm happy.

After running for a while - the pool of gas was gone - so I'll check it over the next few weeks and see if it returns in any significant form.

Thanks all!

Well done & all credit to you for persisting with it, there were certainly a bewildering lot of if, buts and maybes.

Yes it would be nice to have a definitive answer but enjoy the moment for now.

 

[mferris]

Made some reasonable progress on my issues today. I believe that the problem (or at least some of the problems) were fuel supply, both over and under pressure.

I added a Holley regulator, and inline fuel pressure gauges both between the pump and regulator as well as after the regulator before the carb.

With the post-regulator pressure set to 1.75 psi, and pre-regulator pressure would run at 4-5psi (I have a mechanical pump). It would start and idle great, I could rev it without backfires - so I'm guessing the new (and old) 32/36 could not handle the 4-5psi from the pump. However, as you see below, there may have been a starvation/burst issue which could have been jumping over 4-5psi.

But on trial runs of more than 30 seconds and a slight uphill, would die with both pre- and post- regulator pressure down to 0-1psi.

I jacked the entire car up, pulled the fuel line near the pump and instead of a steady gravity-fed flow, it would barely drip. I then opened the fuel cap for venting and blew in compressed air into the fuel line back to the gas tank. After some suction to get the flow going, some flakes came out of the line (see pic) and all is good now.

Ran it for about 10 minutes up/down hills without unexpected issues.

So I'm off to the forums to search on how to clean/reseal my tanks!

One question - my SV has hard, flexible plastic (PVC?, not rubber) fuel line going from the tanks to the engine, is this common or should I have metal lines?

Thanks again for everyone's help.