The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by Karl M, Aug 20, 2019.
Got brave and drove it to work this morning. Ran good all the way, six miles. Got to work, put it in park and reved the motor...black smoke. More adjusting needed...float level, air mixed needles.....?
Thanks again for the info.
When I run into something confounding when troubleshooting an issue what usually works best for me is to kind of back up and start from scratch, from the beginning, and "assume" nothing. Have you measured the static fuel pump pressure output? Your vacuum gauge will do this. Pressure is not a substitute for volume, check to see that plenty of clean fuel is delivered. Direct the fuel pump output into a clean container and see that at least a pint or so is supplied in 15 to 30 seconds.
Lots of defective fuel pumps out there these days. Then check the wet fuel height in the bowl is at spec after idling a couple minutes. Fuel level is not the same thing as float height, the fuel height in the bowl is what counts because every carb circuit is calibrated around a specific fuel level being maintained from idle to wide open throttle, usually within a 1/32" in. Check that the float isn't sunk due to pinholes or something like that.
Another base line to look into. Has your carb been opened and altered from factory specs in the past? https://documents.holley.com/techlibrary_carb_numerical_listing.pdf
A little black smoke doesn't mean much on it's own , maybe change the accelerator pump cam or just cam position , maybe a smaller set of shooters ( discharge nozzles), many things to try.... I don't remember seeing the size of the carb , may be just too big ......
Got home check the accelerator pump arm-good, adjusted float level. Turn passenger side idle screw all the way in and carb never stumbled!. Blew it out, no blockage. Turn fuel regulator down to 3.5 before I could get the idle screws to work right. Not sure if this is such a good regulator. Out of daylight now.
Don't know for sure. Kit I bought came with a 7.5 power valve, the one that was in the carb was a 6.5.
Just because the regulator say 3.5 lb doesn't mean the fuel pressure IS actually 3.5 lb. It needs to be checked with a proper gauge.
What are you running for a fuel pump?
Today's mechanical pumps are terrible in the pressure department. Often they make to much of it.
Those little regulators are notorious for not working.
That regulator isn’t worth the cost to send it here from China . If it is working tomorrow it may not when you need your most to be running
A 7.5 opens earlier than a 6.5. I prefer to run a power valve where the mixture starts to richen at a lower vacuum. I live in mountainous country, where economy unnecessarily suffers when the power valve opens earlier.
Did you check that the faces on the carb were true? An internal leak between the carb face and the metering block can cause it to run rich.
What do you mean you checked the pump arm ?? What. Is. The. List no. On The. Airhorn ????
Do I detect some Nicolas Cage?
Just another crotchety old bastard
Accelerator pump...is adjusted correctly.
Any recommendations on a good fuel regulator? I see Holley sells a variety of them.
List- 4548 - s
That's a 450 cfm ford spec 4bbl ,it's jetted fairly lean(#59 pri) so if it's running rich , it's probably a needle and seat/ float/ fuel pressure type problem , there's nothing wrong with the Holley deadhead fuel pressure regulator 12-803... The accelerator pump shooters are supposed to be #21 , that's very small , check to be sure no one's changed them..
Thanks, just checked the regulator out with a pressure gauge, all settings dead on. So will continue to check out all the advice given here. One thing the started is real slow cranking, may have to see if a high torque stater is better and or run another ground. Don't know if that dumping to much gas in the beginning.
If it's a stock low compression engine then there's no need for anything more than a stock starter ...
This is a timely thread as I just rebuilt the 1850-4 that resides atop the 390 FE in my late 60s truck. It is running the best it ever has now but I can't seem to stop a leak from the balance tube at the rear bowl. It almost seems like the tube was replaced at some point prior to my ownership as it doesn't look stock to me? The rebuild kit came with umbrella type seals but they are bigger than the ones the carb has. Are different tubes available somewhere? I looked on the Holley site but don’t see anything.
Make sure the tube is in good condition on both ends. I've been known to put 2 o-rings on each end and lubricate them well before trying to assemble.
Well that's the thing, the tube looks just like a piece of aluminum that someone cut? What do the ends of the stock tube that takes o-rings look like? Is there a shoulder or a groove for the o-ring?
There is a shoulder at each end to keep the o-rings from being pushed too far down the tube.
Ok that’s my problem then. There is no shoulder. Just a plain tube. Poop.
When looking for a transfer tube there are 2 different lengths , one for a carb with sec metering block , one for a sec metering plate ....
No secondary block on mine. The series number should denote that yes?
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