new engine runs too rich HELP!!

Wareagle

Wareagle

Member
Hello all. Been a while since I've posted. Got engine rebuilt with Snyder 6.0 heads, Ford model 94 carb, mallory distributor from Bubba and a set of headers. Engine runs extremely smooth. Compression runs around 110 psi in all cylinders. Engine fires on first revolution or two. Problem....pulled plugs and they are real black. If I lean it out, the engine dies. I've adjusted the float several times. I'm running out of ideas. Any suggestions??? Pic below is the current set up. Thanks
 

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It would appear that your fuel line is running uphill. Are you using a pump?

Also it looks like your air filter may be a tad bit too small.
 
When you say you leaned it out are you talking about the idle mixture screws
or changing jets.

Bob
 
Fuel line is pretty much level with the ground. Tank is full so I'm getting plenty of fuel flow. The idle mixture screws are adjusted to let it idle smoothly. If I remove the air cleaner, it dies. It will stay running if I place my hand around carb inlet and help meter the air. Exhaust burns the eyes.
Runs smooth at all rpm's, just rich as heck.
 
you have a vacuum or fuel flow problem , the air cleaner is acting as a choke, same with you putting your hand over the carb, your hand is acting as a choke, check manifold gasket, carb base gasket, and carb gaskets
 
Carb has been apart soooo many times just to get all the leaks stopped. What do I torque the manifold gaskets to? I think I torqued them to 35. Maybe I'm a little lite there. Also forgot to say I'm running the new Stipe 330 cam. Should I spray the gaskets with carb cleaner to check for leaks?
 
An unlit propane torch is also a good way to check for vacuum leaks.

If in fact your air cleaner is acting as a choke, you may well check out getting something with a little more surface on it for a permanent solution -- once you find the problem, than is. Ideally, the air cleaner shouldn't make much difference whether it's on or off.
 
What is the idle vacuum reading. If too low, the 94 will continuously dump fuel through the power valve.
Try a Stromberg carb, see if the problem goes away.
I've never been able to get any downdraft setup to run great using only gravity feed.
What is the ignition timing set at?
Ken
 
I ordered a couple of sizes of main jets but haven't received them yet. The Power valve is the stock valve as is the main jets, .050 I think. I ordered a set of .040 and a set of .045 and also a 10.5 power valve. What does the manifold torque to? Air cleaner will also get bigger. I was wondering if I had too much carb for the motor.
 
I don't see the linkage connected to the carb, so can I assume this hasn't been driven on the road?
If the engine is running good, I wouldn't worry about plugs color when the engine has just been run in the shop.
 
Jim,
I run two 97 Stromberg, with stock jets, idles clean.
That being said, I spent many hours playing with ignition timing.
Are you running a stock distributer?
My engine is 8:1, Lion head, 2 Stromberg 97s, header.
Previous setup, I tried two 94's, could never get the power valves to stop dumping fuel. Tried plugging the PV, then lost off idle throttle response.
The firing order of an A engine plays havoc with the PV.
PM me if you want, can discuss further.
Ken
Cleveland, Ohio
 
just for grins you might try the e-3 plugs . I run a weber & it was rich at idle , changed to the e-3's , no more black plugs or fumes at an idle . just my thought .
 
Holley carbs use a rubber diaphragm in the power valve.

If engine backfires too many times the rubber can be damaged and the power valve floods the engine depending how large the crack in the rubber is.
 
Thanks Ken. No I have a mallory setup from Bubba. Timing seems good. Points set to 18. I have set it on tdc several times but it seems to like 4-8*. Starts right up and throttle response is good. Haven't had it on the road yet. Throttle controls still being fabricated. When you say messed with timing a lot to get it to run right, what did you end up with?

Checked all gaskets using the propane. It had no effect. Where can one find agood rebuilt Stromburg? Just in case.
 
Vacuum at idle is 18hg. Power valve is stock. I ordered a 10.5 pv just in case. I will try and advance the timing and see what effect it has. Where do you get e-3 plugs for a model a?
 
Jim,

For my combination, I used a Mallory dist with E-spark conversion.
Initial timing at 16 btdc, total at 26 degrees/3000 rpm
I'm using regular Motorcraft plugs.
I have heard good things about E-3 plugs, will be trying them in my new engine.
I have several Mallory dist, would recurve one on my Sun machine, stick it in the car, try it. The butt dyno tells you what works and what doesn't. I've been running this combo for 6 years, 20k miles. Never loads up, starts immediately, even in the middle of winter.
You just need a little tweaking. Lot of very knowledgeable people on this forum, you'll figure it out.
K
 
Thanks Ken. I did go out and bump timing up a bit. It now runs without the air cleaner on it, but still will burn your eyes. I might try to bump it more tomorrow. Might pull distributor and start over.

Thanks guys for all the suggestions.. I will try each and every one before I give up. Lot of knowledge here for us slow guys to absorb. Just don't get too impatient with us. We're trying.

Thanks again,
Jim
 
Jim, Is the PV new or an OE that was in there? If the PV is bad, it will dump fuel into the carb. What does happen if you close the idle screws? If it does not stumble/ stall you definitely have too much fuel going to the motor. If you have to turn the idle RPM set screw way up, it may be bypassing the idle circuit and going way rich.
Just some thoughts... maybe you already checked all this.
 
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