Weber problem, still can't start, HELP!

[joehahn]

I am sorry to take up bandwidth with pretty much the same questions but here goes:

I have spark, air, compression and I recently redid my tank so I know it is clean. Fuel pump is ok too (don't know pressure but I know it works). New plugs too.

Car will not turn over. I took air cleaner off and pushed linkage with my hand and noticed that I was getting no juice AT ALL out of the nozzle thingy on the left carb and a drip out of the nozzle on the right carb (nozzle meaning the little thing you can see while looking into the throat that spurts a spray on acceleration). I could not see down into the front most funnels of the 2 banks of carbs because I didn't have a mirror.

Does this mean there is a blockage somewhere? If so where do I start narrowing down the block? I removed and looked at the "main jets" but they looked clean.

PLEASE HELP! I only have one month before I have to put car away. Thanks fellas.

Joe 68L (40 IDAs)

note: when I first got my car back from mechanic in May after carb rebuild I noticed that when I pushed linkage all the nozzle thingys produced a nice spray into each throat. Now they appear to not provide any and each throat looks bone dry. I am honestly thinking about throwing in the towel on this car. It would be nice to see my family again anyway.

[Formerly Steve Wilkinson]

Do you literally mean the car "will not turn over" (which has nothing I can imagine to do with the carbondaters) or that it will not catch and run?

Stephan

[joehahn]

..thanks Stephan, kick a guy when he's down! Seriously though I am certain if I had a back hoe I could get it turned over but I guess that is what I meant to say, starter runs and soounds if it wants to start but just doesn't quite get there.

It wont "turn over" but it definitely knows how to "play dead".

[Zendalar]

I guess you really have checked at the carb end that fuel is coming out of the hoses? The next thing would be to check the needle valves on top of float chambers. The valves might be stuck so that no gas gets into the chamber and therefore nowhere else.

[joehahn]

Zen, you and I had the same conversation via a post in June! I apologize for the redundancy. Could you please tell me which numbers on the diagram below I should be checking? I thought I had a decent grasp on the carbs now but I guess I don't. I searched archives and found a post that indicates the best thing to do is remove hoses piece by piece and let them dump into can or jar with pump running to first see if there is a block BEFORE carbs. If all checks out up to that point I am screwed as I don't want to tear apart carbs. Wayne, does the book have a section on rebuild as well as tuning?

http://www.pelicanparts.com/914/Parts/914-6/914-6_weber4_big.htm

[Zendalar]

part number #6. You really should not worry about taking apart the carbs, but do that float valve check first .

There are not so many parts in all =)

//Zen

PS: You can take off the upper part of the carb, the part which has the needle valves. This way you can check if the gas is really getting through the valves. Couple bolts. Can be taken off without removing the whole carb.



[This message has been edited by Zendalar (edited 09-25-2001).]

[jabb]

I have some Doc on how to tune webers
I can fax to you... Fuel pressure and Float levels are important for Webers to work.
There is also a test you can do to see how much volume is being released when you activate the Throttle.


------------------

• Joe A.
• 84 911 Targa
• 75 914/6 3.0

[Formerly Steve Wilkinson]

Dirt is a big deal with Webers. Tiny blockages can form, and though you'll pull a jet and it "looks" clean, lord knows where the blockage actually is. Also, you say you "know" your fuel pump is working. How? Because you can hear it? Means nothing. I jsut replaced a pump that hummed away merrily but pumped nothing.

First thing I would do is remove the fuel-delivery hoses where they connect to the carb filter body or manifold. (I have PMOs so don't know exactly how the Webers are configured. Turn the key on and see if you're getting fuel, obviously with some kind of safe receptacle for the fuel if it does come out of the hoses.

I suspect you'll find the fuel pump has gone tits-up. I can't imagine that neither accelerator pump works or that all four float-bowl levels are so far off that nothign delivers fuel anywhere. Betcha you aren't getting gas to the carbs.

Stephan

[joehahn]

Zen, if i do remove the top portion and futz around with it will I need to replace that gasket? (#11)

[Zendalar]

Nope, in that part there is no pressure or vacuum, the old papergasket will do just fine, as long as you don't rip it. Some people use vaseline to old gaskets, this helps with leaks, in case you are worried about it.


[This message has been edited by Zendalar (edited 09-25-2001).]

[dhaines]

First thing I would do is to pull the drain plugs on the float bowls and see if they have gas in them. Have something to catch the gas as it comes out. Save you having to tear the carbs apart and is easy to do.

------------------
Doug '67 911 2.2

[joehahn]

dhaines,
That's funny you should mention drain plugs. I removed those first and actually screwed one in too far thus breaking the S.O.B off in the carb! Therefore the whole project came to a screeching halt until pierce manifolds could ship a $3 screw ($5 to ship) across the United States. I hope at the very least you people are getting a good laugh outta this!

[J P Stein]

Had to chuckle about the broken plug,BTDT.
I think they teach about this in "Webers 101".
I missed that part of the class, also.
They are designed to break when over tightened.....notice the hole drilled thru there? It makes a nice slot for a screwdriver, eh? Hope you bought more than one.

As to the engine not firing,
I agree that the fuel pump is the prime (NPI) suspect.

JPIII

[john walker's workshop]

a little 3# max. pressure inline pump can be used to replace the original pump.

[stormcrow]

Joe,

Sounds to me like you may not have any fuel in the fuel bowl, or the pump assembly may be the problem.

When you push the throttle down, you should see a vapor of gas come from the venturi. As you have stated, you did not see any.

Check the fuel bowl for fuel. If none is there, disconnect the fuel hose to the carb, get a beacon and place the hose in it and have someone turn the key to the start position.

If no fuel is streaming out, then it is the fuel pump. If you have fuel there, then the float is stuck in the bowl not allowing fuel to enter.

Once you have checked this out, make sure your idle screw is adjusted properly along with the air mixture screw.

I havn't worked on this type of carb, but have disassembled many a quadrajet to work on them. I think this would be a good starting point to troubleshoot the problem.

Steve

[joehahn]

...and the winner is..STEPHAN and J.P. (and Kurt V.)with the bad fuel pump diagnosis,

I pulled out line from pump and stuck it in 2 liter bottle, turned key, and the sneaky little bastard was making the whirring noise for a few seconds, dumping a few teaspoons of gas and quitting.

Can I really just get any run of the mill pump and throw it in there (I am assuming John Walker means 3 pounds of pressure?). I hope so as I believe they are expensive?

Few more comments..
1. Thanks again for the help
2. "Tits-up" is my new favorite term for something that has died or failed.
3. J.P., yes I was tickled to find that the little hole accepted a tiny screwdriver. Big swing of emotion going from "Oh FUK!" to "Oh thank GOD!"

anyone got an extra pump....

[Don in Redondo]

Dis-assemble fuel pump, many have screen filter elements in the baseplate area which can cause blockage.

[CamB]

I'm not going to post the link here, but Automotion have a fuel pump "for carburetor conversions" for about $50 and I am sure Wayne will sell you something similar.

Mind you, the original is probably very pricey (it is Porsche tax and rarity).

Correct me if I am wrong, all you need is 3-6psi? Not a big ask.

Cam

[Zendalar]

Facet Silver Top, pressure 0.30 bar, no need for external pressure switch. Fuel lift height max 60cm.

I have this on my car and works like and a charm. I installed it in the air conditioning box because i don't have AC.

[Formerly Steve Wilkinson]

T/U is the politically correct substitute for tits-up, by the way, if you ever need to be more polite than we are.

I have carburetors (PMOs) and they work just fine with the stock '83 SC fuel pump, with a restrictor--basically a round clamp--on the return line. You don't need the big, expensive Porsche "carburetor pump." You need 3.5 psi for road use, 5 or 6 psi for the track. I have a little pressure gauge in the engine compartment that allows me to adjust/change the fuel pressure easily.

STephan