1960 running rough after carb rebuild

[vermbird]

i rebuilt my 4100 autolite following Mikes carbs tutorial on his website. carb primary venturi squirts well. but hesitates on giving it throttle, if i open the throttle wide the car sputters and dies. i have adjusted he floats a few times, i put fine wire thru all the passages when i had it apart and blasted it well with baking soda when apart. i don't think its the pertronix ignition acting up. it idles ok. should i have it troubleshooted by a good carb shop? send the pertronix out for check to the company in the L.A. area? put the points back in? getting frustrated and tired of taking the carb off and on. in san diego.

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[jack-in-sac]

The Ford 4100 carburetor is a pretty dependable carb. However I have not looked at one for quite some time. On Holleys a common stumble can be a mis-adjusted accelerator pump. A common problem for an accelerator pump is a diaphragm being damaged and or an adjustment or travel. This might be a starting point.

 

[paul4913]

Power valve and/or secondaries ?

 

[vermbird]

not too much to adjust on the accel pump, it is new,as is the power valve. i am puzzled. its such an easy carb to rebuild

 

[Douglemmo]

I believe you have a carb issue not an ignition issue. Electrical things usually work or they don't. Do you have a blue spark at the spark plugs? Primaries don't squirt anything the accelerator pump squirts. You should have a good stream of gas when you actuate the acellerator pump. If not adjust the pump to pump more gas. Also,. The power valve should be closed during idle. Since you are getting frustrated, there is nothing wrong with taking the car to some who can adjust your carb. Watch what the do and you will be smarter the next time.

Good luck

 

[64ZCODE]

I believe you have a carb issue not an ignition issue. Electrical things usually work or they don't. Do you have a blue spark at the spark plugs? Primaries don't squirt anything the accelerator pump squirts. You should have a good stream of gas when you actuate the acellerator pump. If not adjust the pump to pump more gas. Also,. The power valve should be closed during idle. Since you are getting frustrated, there is nothing wrong with taking the car to some who can adjust your carb. Watch what the do and you will be smarter the next time.

Good luck

What Douglemmo said. Sounds like a fuel delivery problem. Suggest ensuring fuel pump is pumping up to snuff and fuel filters (in pump and inline) are not clogged. You've already checked float levels. The accelerator pump linkage needs to be adjusted so it starts to squirt as soon as the accelerator linkage starts to actuate. A defective power valve isn't it, that would either result in flooding the engine at idle (valve blown or stuck open) or hesitation when mashing on the gas at mid-range speed (valve too small).

Doug

 

[Critterpainer]

Power valve not opening at all??

 

[Hemoguy]

i rebuilt my 4100 autolite following Mikes carbs tutorial on his website. carb primary venturi squirts well. but hesitates on giving it throttle, if i open the throttle wide the car sputters and dies. i have adjusted he floats a few times, i put fine wire thru all the passages when i had it apart and blasted it well with baking soda when apart. i don't think its the pertronix ignition acting up. it idles ok. should i have it troubleshooted by a good carb shop? send the pertronix out for check to the company in the L.A. area? put the points back in? getting frustrated and tired of taking the carb off and on. in san diego.

are you sure your hesitation is due to fuel? maybe you have a vacuum advance problem or vacuum leak. it is always good to have someone in knowledge go over your workmanship just to see if you connected something incorrectly. best of luck.

 

[vermbird]

so the primary bolt float was not rising, the spring that holds it was twisted. i fixed that, put the carb back on, in now runs but when i took it for drive it would not go up even a mild incline, sputtered, bogged. i don't know what the problem is. i had taken it apart recently and blew out all the small passages and put fine copper wire thru all the little holes. no tears in accel pump or secondary diaphragms. power valve move freely, no obvious cracks in the carb body. these autolite 4100 carbs are real easy to rebuild. i just dot know how next to troubleshoot it.

 

[Ward 57]

It sounds Like you have the carb issues resolved. Now to look at vacuum and advance issues. There are few and more dyeing off that would know where to look. There are many that want to go to new technology but the old stuff worked well. Try to find an old school greasy garage that has been around for a long time and avoid 'parts replacement' shops that service newer cars and have no clue to 'Analog' cars.

 

[vermbird]

still think its the carb. i had another t bird with good carb and put that carb on the car that's not running well and its ok. runs ok. so this rules out an engine vacuum leak . i also set the timing with my timing light about 8 degrees before tdc. i think there is something wrong with the carb i .rebuilt just need to find someone who; can troubleshoot the 4100 without charging me for a complete rebuild since it has all new parts, accel pump, secondary vac diaphragm, power valve, needles/seats. floats adjusted to height specified, all new gaskets, didn't forget the check balls in the primary venturi, and the accel pump. anyone out there an autolite 41200 carb expert.

 

[Critterpainer]

Do you have a second Ford that you can put the mis-behaving carb on? Do you have a vacuum gauge that you can check intake vacuum?

 

[Ward 57]

still think its the carb. i had another t bird with good carb and put that carb on the car that's not running well and its ok. runs ok. so this rules out an engine vacuum leak . i also set the timing with my timing light about 8 degrees before tdc. i think there is something wrong with the carb i .rebuilt just need to find someone who; can troubleshoot the 4100 without charging me for a complete rebuild since it has all new parts, accel pump, secondary vac diaphragm, power valve, needles/seats. floats adjusted to height specified, all new gaskets, didn't forget the check balls in the primary venturi, and the accel pump. anyone out there an autolite 41200 carb expert.

As an aside. You have all the new parts, I'd slowly take it apart and re-evaluate your rebuild. You don't do it every day and there may be a simple fix that as an apprentice you would not catch. Carbs are complicated with fluid dynamics and air flow and there is no book out there that can replace experience. You sound like you are pretty handy, and you are close. All it takes is an 'O' ring not seated correctly. I'd use assembly fluid on everything and what is overflowed will quickly wash away but let parts seat.

 

[vermbird]

thanks for your reply. will take it apart again and look. no real o-rings on this 4100 carb. what is assembly fluid? could be the float level though. i can adjust the floats with the carb on the car and the engine running!. the top comes off and exposes the floats, needles/seats etc. thanks again. vermbird.

 

[Ward 57]

thanks for your reply. will take it apart again and look. no real o-rings on this 4100 carb. what is assembly fluid? could be the float level though. i can adjust the floats with the carb on the car and the engine running!. the top comes off and exposes the floats, needles/seats etc. thanks again. vermbird.

Assembly fluid is used when assembling moving parts, commonly used on brake parts.

 

[stevetheweave1]

Using an air nozzle to blow out jets can jar lose the mfg passage way plugs. Try putting some sealant on 4 plugs on top of the primary and secondary nozzle bars. Easy attempt to fix a possible lean condition without having to remove carb.