I have been taking advice from many of you already, thank you for your valuable input. I tried to start my car this weekend with this rebuilt engine. It cranks, but I have no spark, no vacuum from the fuel pump. I have read topics about the aftermarket electrolock wiring. I do not have an electrolock. I have a 3 position 6VDC key switch, that has maintained positions, not momentary. I can see the points making and breaking ground with my Fluke meter(while monitoring voltage from the negative side of the coil to the input of the distributor). I am not sure that I have this wired correctly. How should I have the coil and distributor wired from this key switch? Any pointers about the fuel pump not drawing fuel? It seems to crank faster when the have the clutch pedal released. I am trying to get this running before is snows here in lovely Wisconsin. Thanks in advance!
The wiring should be positive battery terminal to ammeter to ignition switch to positive post on coil. Negative post on coil to movable point arm. The static point arm is grounded completing the circuit. You should be able to test for spark by open and closing the points with the center coil wire that goes into the distributor held 1/2" from a ground on the engine and then opening and closing the points. If you don't get a spark then short across the points. If still no spark then check places along the circuit for voltage. Put insulator between points or you will only get a fraction of a volt.
Failure to get any gasoline flow can be plug in line from tank, leak at settling bowl gasket, defective diaphragm, loose connection and a few more.
Yes the drag of the throwout bearing can reduce engine cranking speed. Always start with transmission in neutral and clutch pedal fully out.
Fuel pump issues can also be caused by the two valves located on top of the pump sticking. Remove the two nuts and put a little gas in the chambers and also check that the valves are not sticking and that the small springs are seated correctly.I have had that happen to mine. Also check that the carb intake needle valve opens #18184
can do a quick check on the Fuel pump by disconnecting the fuel line from the fuel pump (gas tank side) and use a Vacuum/ Pressure Gauge. Hold or connect the Vacuum Gauge to inlet side of Fuel Pump (gas tank side), Crank engine over a few times and you should get a Negative/ Vacuum Reading.
If you are NOT getting a Negative reading then something is wrong with the pump. Check the above noted Springs as well as the diaphragm to make sure it is not torn or has a hole.
Also check to make sure that the gasket around the glass fuel bowl is SEALED, if not the pump can be sucking in air here as well. Should be a nice rubber gasket in there. here is a link to my Discussion about the fuel bowl , filter, gasket 1929 Fuel Filter, Screen, & Gasket Installation
AACA - VCCA - Stovebolt - ChevyTalk Love the Antique Chevrolet's from 1928-1932 The Beauty, Simplicity, History, and the Stories they Tell
Actually most people don't have a vacuum gauge so that test is not possible without an additional expense. The other way is to have the spouse of neighbor crank the engine a couple of times while you hold your finger over the inlet of the fuel pump. Immediately after the engine stops take your finger off and see if you hear a sucking sound. Or pst with your finger on the outlet side.
You can also blow back on the line to the tank and listen for bubbling in the tank. No bubbling means the fuel in the tank is below the pickup tube or the line is plugged.
If all that is okay then check the needle/seat in the carburetor to be sure they are working.
Ok, I got past this, the car ran briefly. I shut it down with concern of mechanical noise. Now, I cannot get this started again, I have spark, compression, no fuel. Does this fuel pump operate from any vacuum from the carb? I have a vacuum gauge and measured 2 inches of mercury at the inlet of the pump
If the pump arm is wore out does anyone make a replacement? I rebuilt my pump with a kit from the Filling Station. I wasn't sure about the valve spring length, so I stretched them out. Should I have left these springs in a short length? Is there a difference in which valve plug or air dome is used?
I wasn't sure about the valve spring length, so I stretched them out.
Why would you do that? The valve springs that come in the kit are the correct length and they have the correct tension. The springs are installed as is. That could be the reason why your fuel pump is not working correctly.
I stretched them because that was the way I found the springs I removed when rebuilding the pump. I will source some more locally I guess. What length are these suppose to be?
You probably won't find the correct hair wire valve springs locally so you will have to probably buy another kit from the Filling Station for your AC 405 fuel pump. The valve springs that come in the kit are the correct length and tension so you use them right out of the kit.....do not stretch them!
If the pump arm is worn it can be built up with braze or weld. If you take either option then only add enough to restore the original dimensions. The two valve springs regulate the opening and closing pressure of the valves. Altering their length can make the pump fail to operate properly. Some people mistakenly think that stretching the springs will overcome leaking valve wafers.
The air dome was intended to overcome a minor deficiency in operation. I have never found a difference in the performance between the flat plug or air dome.
I have found a difference between the flat plug and the air dome. Without the air dome I have found that some of the fuel pumps will tend to pulsate with their pumping action. With the air dome installed there was no pulsating.
The problem could still be your fuel pump if the valve springs that you installed from the hardware store do not have the same spring pressure as the original hair wire valve springs.
If the springs are correct and there's still a problem, check the cam and the stroke of the pump. It's possible to assemble the links and pins incorrectly. Turn the engine to get the highest side of the cam, move the pump into place to check the length and range of the stroke. Check for an air leak at the glass bowl, that could be a gasket or a warped casting.
If you have old Chevrolets, other old Chevrolets will find out where you live.
I got it running after adjusting the timing and carb some more. Bought the correct springs for the fuel pump. Still have to adjust the valves hot and play with the timing and carb. I have attached link for video I took of the car running after 46 years.
