I have a Weber 32/36 and after over a year of being off the truck for a full restoration job, I have a hesitation in throttle response upon first application of fuel. The engine will literally "bog" down, but not stall, and then jump to life with a nice full rev of the engine. It does not miss or anything like that, this is a simple falling off and then an immediate pick-up of engine rpm's.
The main problem is drivability of course since every time you want to step on the gas it flop sweats. If you place a heavy enough throttle application down sometimes you can push past it with only a small drop before taking off but then at times it will just fall flat and snap to life with a jerk of your head and a buck of the truck in response...not smooth at all for road use.
I was not sure if the Weber was getting the proper amount of fuel since my regulator was set for my old fuel pump that frankly..stunk. I purchased a new OEM one for my rebuild (and a new fuel tank, lines, filters, etc.) and it still hesitated so I ran the fuel line straight from the fuel pump right to the carb (with the potential for too high of a fuel load) but it still hesitated just the same.
Is it possible that the other parts of the carb need to be taken apart and cleaned after being "down" for so long (i.e. needle valves, jets, etc.), would they possibly cause the issue?
The previously mentioned new fuel tank was installed and I used the original fuel sending unit because it worked fine previously, sadly now that i have it all installed and fuel in the tank the gauge is not working.
I checked the wires and cleaned the harness contact points but still nothing. I used the ohm meter and checked the switch and it showed 93 ohms which would be "empty" on the gauge, which is exactly what the gauge is showing, problem is...it has about a half tank or so of fuel right now so it should register much lower at about maybe 35-38ish.
Upon testing the main wiring coming back to the switch the voltage was all over the place reading 2 volts one second and 11.59 the next, I couldn't make much of that really.
I am REALLY not looking forward to taking this tank back out and removing the sending unit now that it has a bunch of fuel in it to replace the sending unit.
If you have any ideas or better yet "experience" with these two items I would love to hear them.
Engine off, look down the carb and work the throttle. You should see a strong squirt of fuel. This is the accelerator pump. If not working or weak it needs fixing.
Ground the Yellow/Whiter wire with the key on... you should get a full tank reading. No reading would indicate a faulty gauge or wiring between it and tank.
Ground the Black wire. If this gets any reading, the ground wire is at fault
As it reads 93 ohm, this would indicate the float is stuck in the down or empty position. Drive it with sudden stopping to slosh the gas around. This may dislodge the float. Otherwise you will have to remove it..... again.
The 32/36 is a progressive carb. This means that no matter what, when the primary is 1/2 or 3/4s open (or whatever it is) the secondary is forced to open also. Try opening the primary with the engine off. Make sure the primary opens fully and the secondary should begin opening at 60% or so. I don't believe the secondary does spray as the engine will be well revved up by the time it begins to open.
The accelerator pump diaphragm is on the outside of the 32/36 and can easily be removed and/or replaced if the pump output is low or erratic. Having said that, there is more to just off idle acceleration than the accelerator pump. It can be a lot of things including timing and ignition and wrong jet to clogged jet. Here's a couple of links to trouble shooting a 32/36 and setting the idle properly.
Check out the slow speed circuit. On the inside of the carb base just above the the idle mixture screw is a slit. It's above the throttle plate so not used during idle. But as the throttle is opened intake vacuum is applied to the bottom of this vertical slot and sucks fuel out. Any blockage here will result in poor low speed throttle response. Farther above this is an air bleed that again is easily blocked. in fact the idle cut solenoid is just below this for shutting off idle fuel. There is also another (much larger) air bleed for the primary venturi that must be clear and the emulsion tube below it.
Use a can of carb cleaner that comes with a straw so you can force cleaner through these small holes.
How much PSI are you getting from your fuel pump,should be no more than 3 PSI,I just installed a new Redline,32/36,and I installed a fuel gauge and it is reading 3 PSI.Maybe your fast idle screw needs adjusted up,Remove your air filter,turn throttle all the way by hand and hold then turn your buterfly,then go start,don't touch the gas pedal,after it starts,it should go to 2000-2500 rpm's,if too low,turn off and get flat head screw driver and turn fast idle screw in some,then go start and see where it goes to,adjust till it's in the 2000-2500 rpm range.I am using a oem fuel pump,BECK Arnley,it says it's not good to use a fuel pressure regulator to decrease the fuel pressure,will cause fuel to back up to the fuel pump causing it to strain and make noise,if it's higher than than 35 PSI,Then get another fuel pump.Also check the 2 fuel lines by the passenger side by the oil filter for leakage,mine leaked their.Also,go to Autozone and have your battery and alternator out,when I put Weber on,Alternator was bad,when I started it,it would die,went and had both checked out at Autozone and Alternator was bad,installed,started up,then idled fine.
Did you spray the base with brake cleaner while its running to check for leaks,or you can get a rebuild kit,or I would get 298.00 and get a new one.