Technical Stromberg issue...any ideas or help?

Hey guys,

I’m experiencing a perplexing issue with the rear carb on my new Stromberg 97s.
(English Strombergs from Clive and Uncle Max.)

First it was passing fuel dribbling out the top of the accelerator pump felt and dribbling fuel on the throttle blades after shut down.

I tried lowering the float level and that seemed to help however now when the engine is running the carb at idle is dribbling fuel constantly on the throttle blades.

The front and middle carbs are not doing this when you look into the carbs at idle the front and middle carbs are working fine and running on the idle circuit.

The fuel dribbles constantly on the throttle blades of the rear carb at idle and for about 30 seconds after shut down.

This is not a fuel pressure issue as the other 2 carbs are working fine.

Any ideas or knowledge to share?

Kinda sucks because I can’t drive my RPU this way with excess fuel dribbling into the engine from the rear carb.

 

I'd say psi., The Last carb would have the least resistance

 

Thanks, but I think there’s something different going on in my case as the main problem isn’t after shut down as much as it is the constant fuel dribbling on the throttle blades at idle.
The front 2 carbs are functioning perfectly at idle with no excess fuel dribbling onto the throttle blades and don’t do anything after shut down either.
I have a fuel shut off solenoid that is off when the ignition is off as well.

 

Fuel pressure is 1.5 psi with the Aeromotive fuel pressure regulator.
I can’t see why fuel pressure would cause the carb to dribble excess fuel at idle.

 

That’s maybe the case although it’s a Grose ball valve type thing.
Any idea how to fix that other than replacing it?

 

This is most likely what you are facing if the float level is correct. The least little bit of dirt or sand or whatnot out out of the tank can keep the needle from sealing. That is where I would look first.

 

This is what they look like

 

There was a thread about this on "The Ford Barn".. The consensus there was that the "Grose-Jets" are inferior to a traditional needle and seat and should be replaced.

 

Another vote for dirty needle and seat.

 

For a test, place a known pressure gauge right where the line goes into the first carb.

Regulators WITHOUT A BYPASS often run higher than dialed pressure at less than maximum fuel flow.

As far as only one carb leaking, as others have said, once one carb relieves the pressure, there is no need for the others to leak.

Jon.

 

Good call thanks for the help fellas.
There was a tiny sliver of thread peel off trash that would not come out of the valve and was almost invisible despite the fact that I had cleaned it out previously.
On close examination in the sunlight I could just see it in the tiny hole. A little bit of work and out it came.


Surprise no more problem working perfectly.
I’m putting the air cleaners back on and going for a drive

 

Did that just to be sure and the pressure is bang on the minimum for the regulator at 1.5 psi.
No problems at all now.
Larry

 

Glad you got rid of the drip buddy! Those STD's (Stromberg Throttle Disturbances) can be troubling and downright embarrassing.

 

Thanks, it’s running really good now.
Leak free for the first time since I got it running.
Had a great drive today.

 

I don’t believe that they’re working perfectly and no problem now.
Clive recommends them and I’ll stick with them.

 

I'm glad things worked out for you.

I guess time will tell.

 

Clive vs ford barn... Sounds like a lame movie but an easy decision. I put another 50 miles on mine just now. Stopped for dinner. Darn those crappy grose valves!

 

Well I'm stumped. I'm running 5 97's on my GMC 302 with Howard intake. After many hours adjusting mixture, idle, linkage all runs great...at idle. The issue comes when I am driving. Backing out my steep driveway, accelerates. (Pointed uphill). Pointed downhill and coming to a stop light, dies. Acts as if fuel is sloshing around in the bowls and either gets fuel or loses fuel. And before you ask, yes, I have adjusted all the floats. If anything the fuel level is slightly low. Stromberg says fuel level should be 15/32" below lip. Fuel pressure is set at 2.5lbs just like my 350 with 4 97's which runs perfectly. Driving the GMC there is no problems accelerating, really pulls with no hesitation. Just don't step on the brakes...blupp, blupp, dead. Starts right up again and I'm off! Help.

 

Check the fuel filter @mpschunks ?

 

Sounds to me like you have a problem with fuel delivery volume.

It could also be related to the balancing of the carbs.
Did you get it running at idle with all of the linkages removed and then set up each carb to pull the same amount of vaccum using a Uni syn carb balancer?
then when each carb is adjusted and idling the same you can hook up the linkage.

 

Excellent question. Yes I did balance each carb then attached the linkage. I'm running an electric fuel pump that is steady at 2.5psi. brand new fuel filter. Again, it seems to be related to the position of the car. incline, runs smooth, decline or decelerating, dies.

 

Brand new inline filter with a steel casing by chance? Did you shake it before installing? Perhaps if you have installed it the glue may have by chance given up hold due to age...

The reason I mention this is I fought a battle with loss of power after starting was fine, runup fine, driving fine, then without warning the problem arises...it ran like it was missing on cylinders minimal power and stalling at idle...but I always made it home...







...the 2 pics are my Spectre Inline Chrome Filter cut apart and what I found...

Last pic is its replacement...

I'm not necessarily blaming the company as Spectre is a known brand...I had the filter for quite some time stored packaged inside a climate controlled environment then installed it...after driving it over time...The problems appeared...remember, you can't see the filter and can't shake it when installed...when I took it off and drained it I shook it and it sounded like a kids rattle...

I truly believe the filter was being bounced around and lodging itself periodically against the outlet to the fuel pump aided by the pull from the pump and restricting the flow to the carbs...since installation of the Napa under 10 dollar inline there has not been another loss of power incident...

For the price fuel filters are one of those things that should be changed out every year or couple depending on distance driven or state of tank...

I'm very fortunate my tank is clean as that was unfiltered fuel for quite some time in my case...

So MPS maybe check that filter out...

Sorry not a Stromberg issue per se but a general across the spectrum whatever carb your running it could be the simplest thing...unscrew drain and shake...