Hi all, new to the board. Seeking help on issues with my 440. Has Holley 4160 just rebuilt, on a new Edelbrock 2191 intake. New plugs, wires, distributor. Fires up as soon as I turn the key, runs/idles perfect but as soon as press the brake pedal and start to move, starts idling rough, blows black smoke out of the exhaust pipe, have to work the gas pedal to try to keep it running but it dies. Have to hold the gas pedal to the floor to get it to start again, but very rough running. Plugs are wet and black. Any ideas what I’m dealing with???? Completed brake booster and check valve tests, both seem fine.
Thank you for any input.
Bill

Welcome ... that Helley carb needs major attention !

With the engine idling in Neutral, take a flashlight and look straight down the carb bores; if you see gas dripping from the boosters the float level is too high.

If you have power brakes disconnect and plug the vacuum line going to the booster and see if that helps.

Carb rebuilder needs a new occupation.....carb is flooding engine w gas.....floats set too high or can't shut off fuel.

I called the guy that rebuilt it and told him that I adjusted the floats and he acted pissed off, said that by doing that, I ruined the needles and seats????? Said to send him back the carb and a check, blah blah blah.
Ty for your input

Ok I’ll try that tonight. I did look down them yesterday, but was in park and could see gas shooting from the side wall in the primaries. I’m not a mechanic so please excuse my terminology. I saw a vid about dry setting the floats, do you think I should start there? I had thought all along that it’s running too rich, adjusted the float level and then I took out the #72 jets and put in #69’s hoping to slow the fuel rate. Not sure that was a good idea or not.
Ty for your help.

There should be no fuel flow through the main jets at idle so changing them wont make a difference ,When you take your bowls back off to change the jets back do a static check on your float level and that should put you in the ballpark. You might also want to check the power valve to see if its wet on the carb body side of the metering block.
Gus

Hi Gus, hope you’re enjoying your Sunday.
So I pulled the fuel bowls off, adjusted the seats/floats to starting point. Installed them and fuel level at site holes were at the bottom of the hole. Fires right up, idles ok, a little shaky, and I can drive it but still seems to be running rich, puffs of black smoke out of the exhaust now and then. Like I said I’m not a mechanic, far from it. I’m wondering if I should take off this Edelbrock 2191 manifold I bought and put the stock iron manifold back on? Is it possible that because the plenum on the Edelbrock is so tall that the carb is too far away from something that all the fuel is not being burnt?? Also, I tried adjusting the air/fuel mixture screws on either side per Holley’s manual, 1 1/2 out to start, then 1/4 turns in until the motor slows, then 1/4 back out and done. But ...... I did 1/4 turns in, both sides and went all the way in to seat position, made no difference on rpm’s of the motor, reason I’m asking if the carb is too high on the manifold.
I’m to the point of a stick of dynamite. Ran so good before I took it to a shop here for supposedly “replacement of the pick up coil in the distributor”!!! What a mess. I’m well aware that it’s not a good time for traveling etc, but if there’s any mechanics out there, in the Reno area, (closest) that are interested in coming to Bishop to work on this thing I can get a room for you plus your travel expenses and of course pay you for your time.

Thank you,
Bill

The other thing is that the seats are screwed so far down that the locking nut has about 2 threads to attach to. Does that seem normal?

Bill

There are two major things you need to check before going any further, fuel pressure and engine manifold vacuum at idle. Fuel pressure should be no higher than 6.5 psi or you're overloading the floats and forcing fuel past them. Check your manifold vacuum at idle and see if it's dropping as you apply the brakes, record that number. Then you need to check your power valve and see what it's rated at, it will have numbers stamped on it. For instance, if you have an 8.5 power valve and your vacuum drops below that when applying the brakes your power valve is opening causing your problem.

Thank you for your input. Fuel pressure could be the problem. I adjust the floats and after driving for a bit the bowls are full again, so I’ll check the fuel pressure first.

Your carb guy is feeding you a bunch of BS. Adjusting the floats won't hurt the needle seats, that's what they're designed to do. If you only have two threads showing your floats are low in the bowl. You can pull the needle seats all the way out and blow out with compressed air to remove any dirt and then screw them back in. Your Edelbrock intake won't cause your problem unless it has a vacuum leak somewhere. Now, your vacuum, the vacuum will drop just a little when applying the brakes but it should rebound almost immediately. If it drops and stays low you have a leak somewhere in the brake booster or vacuum hose going to it.

start by disconnecting everything vacuum related to the intake and carb. plug all the hoses and cap all the ports. you should just have fuel dribble out of the port on the side of the bowl when you take the screw out. make sure your idle slots are not uncovered. if they are you may need to slightly open the secondaries to get more air into the engine.

what godscountry340 & jerry said, & if that dont fix it I would pull the carb & take to another carb guy EDIT or have someone come over & go over everything

Hey, so I just did the vacuum test. Needle was between 13-15 and very sporadic. I found a chart that suggests I have leaky head gaskets. Sound about right???

Bill

not likely iron headed motors rarely blow head gaskets they have to be really really over heated. Normal vacuum for a stock engine is about 22 in so you are way low.....do a compression test and post the results.

I read on another site, possible misfire. I took the plugs out on the weekend to clean them. This time they were dry and black, not wet and black except for #7, still wet and black.

Does this engine have a stock camshaft in it? Performance type cams can often lower vacuum readings.

I believe it would be the original stock camshaft.