particles gets into float bowl

Vido Peran

True Classic
Black particles particles keep getting into the carb's float bowl in my '74 X1/9. The carb is the stock Weber 32 DMTRA 200.

Particles didn't used to get in, but after a carb overhaul by a now defunct Fiat shop, black particles get into the float bowl which plug the jets. I have replaced the mechanical fuel pump with a New-Old-Stock fuel pump and I have replaced the fuel filter and the fuel hoses. But these small particles get into the float bowl and they're lifted by the sloshing when I turn left over a bump (such as into or out of a driveway) and one will be sucked up to a jet hole if the fuel flow is for more than an idle. Sometimes I can force it through with high revs, sometimes I have to stop and turn off the engine and pound on the air filter to dislodge the particle so it drops back to the bottom of the float bowl. Until the jet is cleared, the engine has only idle torqe at best, and it usually dies if I don't pump on the accelerator.

I've replaced the transparent fuel filter twice, and although the filter element may look darkened, there are no particles lying at the bottom, and disassembly shows no gaps for dirt to pass through. I've examined all the vacuum hoses connected to the carb, and they're all tight or purposefully blocked off. But somehow, small particles get into the float bowl - as if the fuel hose between the fuel filter and the carb were slowly disintegrating. (I use Chevron gas.) I've checked the crankcase breather hose that leads to the interior of the air filter, and it's tight at both ends, and I've checked and replaced the air filter twice.

Has anyone else had this problem? Was there a solution?


Vido P.
 
Yep... Sure have...

Mine proved to be the fuel lines especially AFTER I used some FI cleaner thinking it would help. But that stuff really does a number on regular carbed fuel lines, especially when they are the old factory cloth-covered ones. All the "playing around" with the carb and lines just breaks up more bits of crud INSIDE the hoses!

Replace them all (especially AFTER the filter) and also install some steel wool in the blow-by hose as well. Clean up everything and boil out the carb in the dip-in carburetor acid... blow out and reassemble. If you don't... I guran-damn-tee you there will be a flake of crud in there that will come back and bite ya!

I also installed TWO see-through filters ($5 bucks apiece or less) and some "tees" and mounted them so that one is ABOVE the other. I found I had a clogged filter within a few months after clearing my trouble earlier... so the THEORY is now... that the BOTTOM filter SHOULD clog first and the TOP filter gives me a second chance. I keep a couple in my on-board tool box as well.

Hope this helps and solves your problem.
 
There is only about 4" of fuel hose between the fuel filter and the float bowl inlet, but fit is really tight and the edge of the fuel filter nipple is sharp. Perhaps the inner surface of the fuel hose has been cut and then stretched, causing deterioration of the fuel hose inner surface. I'll try replacing the hose and filing down the sharp edge of the filter nipple. My mechanic thinks it might be modern gasoline formulations, but this problem started suddenly, and it was after a previous mechanic put in a Toyota fuel filter and changed the fuel hose.

Vido P.
 
Yep... me too...

It was my messing around in there that loosened something up and caused me a lot of grief.

As I said... it took all that I wrote about to finally clear the trouble for good, especially boiling out the carb. I think something got into the small passages OR... there was some old varnish INSIDE the carb while it sat for years... and finally started breaking loose and clogging the metering rods and emulsion tubes... probably because of the FI cleaner I used.

Anyway... good luck in chasing the trouble and let us know what ya find.

BTW... I'm in Santa Clarita... are you near by?
 
yes, could be loosened dirt

Yes, the last carb boil-out, done 2 1/2 years ago by a guy in Highland Park (Los Angeles), might have loosed some old crud. I have found that to seal the carb base to the intake manifold, he used some kind of glue, and now I can't get the carb off. I'm afraid that if I tried to pry it off, I'd bend some surface and it would never seal again. He's out of business, now, so I can't take it back to him. I can take the top of the carb off, though, to get at the float bowl, and that is what I did 10 months ago. But my car is my only ride, so I have to plan ahead carefully before I start any project that could take more than an afternoon. And current priority is to find a job. (I live 3 miles from LAX.)

Vido P.
 
Well... I see you've been lurking since 2011...

I have a list of about 50 guys in SoCal that try to get together and help each other out every once and a while. Parts, Pizza, Burgers, Beer, and a helping hand 3 or more times a year.

George Aspon is in Culver City who built the Martini Clone and then there is Mike Busman in Torrance with Big Bird but he's half-blind and all thumbs. George is looking for someone who can LEND HIM a hand both physically and motivation-ally to get a new hot-rodded engine installed. Perhaps you can help each other...

I'm in Santa Clarita and if the car will drive that far, I'd be able to lend a hand. I COULD be persuaded to come out that way as well... but prefer to have all my tools at my disposal.

If you would like to become a part of this list... PM me the info you wish to share and I'll add you. Most list their address, or at least the CITY, their phone, private email and a little about their car. In this way we can support each other and our passion. You do need to PROMISE not to share the list outside the group though.

Let me know... or call me between 9 and 9 at 661-296-7277.
 
Has anyone else had this problem? Was there a solution?

This happened to me on one of my cars after, like you, I did a complete R&R of the pump, filter, fuel lines, and fuel tank.

The problem went away after I took the top off the carb, pulled the jets, cleaned out the float bowls, and carefully blew out every single passage with compressed air and carb cleaner.

I never did find an explanation - still makes no sense - I have no idea where the gunk was hiding, nor how replacing everything could have stirred it loose, nor whether my final cleaning of the internals was what made the difference. But it did. YMMV.
 
...If you would like to become a part of this list... PM me the info you wish to share and I'll ahandling dd you. ...

Thanks, BlackTooth, but for the near future, I'll have finding a job as highest priority (that and health problems), and what I actually want to AVOID is making my '9 into a passion like when I first got it. All I want it to do is to carry my sorry butt around until I can afford an Alfa Romeo 4C. :)

Vido P.
 
This happened to me on one of my cars after, like you, I did a complete R&R of the pump, filter, fuel lines, and fuel tank.

The problem went away after I took the top off the carb, pulled the jets, cleaned out the float bowls, and carefully blew out every single passage with compressed air and carb cleaner.

I never did find an explanation - still makes no sense - I have no idea where the gunk was hiding, nor how replacing everything could have stirred it loose, nor whether my final cleaning of the internals was what made the difference. But it did. YMMV.
Thanks for sharing that, EricH. It had occurred to me that the small grit particles might have been hiding inside the carb's passages, but it didn't seem probable. I now suspect that the previous mechanic let his teenage son do the carb cleanout work and the kid didn't clean the outside of the carb before dunking the carb body into the solvent. I'll try blowing out the float bowl, spraying it with carb cleaner, and then blowing it out again. And... I'll wear goggles while doing that. :)
 
blow by

also install some steel wool in the blow-by hose as well.

This would seem to be a very good idea, especially if the car has a lot of blow by. On one of my old Xs, the car would spit carbon particles out the blow by hose. As I had an aftermarket filter on the car where the blow by hose was attached in such a way that the crankcase breather air was not being filtered before it entered the carb, I was constantly having issues with blocked jets.

As an aside, it looks as though many of the after market filters don't filter the air coming from the crankcase breather. What is the verdict on this: could one reasonably expect that air coming from the breather shouldn't contain any particles on an engine that is in reasonable shape?

Cheers,
Dom.
 
I now suspect that the previous mechanic let his teenage son do the carb cleanout work and the kid didn't clean the outside of the carb before dunking the carb body into the solvent.

Now that is the best hypothesis I've heard so far.... explains a lot.

FWIW, I've pretty much given up on the carb-dunking approach - compressed air and carb cleaner is more effort but seems to work a lot better.
 
Good point Dom...

Ya know... I instinctively installed some steel wool in the pipe many moons ago as this was and old trick with FLATHEADS I learned a long time ago. Our purpose then was for the fumes to re-condense somewhat and drip back into the block

I would think this remedy work wells for stopping debris here also... and cheap!
 
Not to be a nay-sayer here Vido...

I've done what Eric has suggested MANY times with only temporary results. Sometimes for MONTHS though... sometimes for hours!

Only when I thoroughly disassembled and soaked the carb, and then rinsed and blew it out, did the problem go away for good.

Just sayin'... Hope Eric's method works for you as well as it worked for him...
 
Back
Top