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So I had just bought a brand new rochester carb from summit racing and after installing everything adjust air/fuel screws for max vacuum and adjusting the secondary air valve spring. When driving it will pull away slowly but if I give it more gas it wants to stall but with a little more gas it picks up and goes but feels like I’m pulsating that accelerator. Any suggestions, maybe timing? New Accelerator Pump was faulty, or I’m missing an adjustment screw that I didn’t see for the pump?
There isn't an adjustment screw for the accelerator pump.
Do you know what jets and rods are in this carburetor? It is possible that they need to be changed to tune the carb for your application. Post what year / engine you have and I or someone else can provide the factory jets and rods numbers so you can see if the new carb is anywhere close to what it should be for your application.
it is a 1971 with the 350 originally came with a 2 barrel but I put a OEM 4 barrel rochester from another 71 but off a 455 it has #71 jets and I’m not quite sure what rods and I know it has the blue ring accelerator pump if that means anything.
so I found on the side of my carb it has the carb number as 7043251 RB this may be my issue but it came with the #70 jets I just thought I was running lean because in park or driving and giving a little gas it sounds like its only sucking in air and the exhaust note is gone like it is about to stall.
Lots of things to check timing would be first. 2. 2 good shots of fuel from accelerator pump. 3. no fuel dripping from primary nozzles at idle. 4. fuel level too low. 5. Throttle plates set correctly at idle (pictured, carb upside down). Not related to your problem but you should have someone sit in the car (not running) and floor the gas pedal, look down the carb secondary side and make sure the throttle plates are vertical. Since it is a conversion you may not have full power due to linkage.
Sounds like when a later model with APT is adjusted to low and possibly making things lean. Not sure if that one has the base plate style APT, but if it does, you can try to 'raise' the primary rods to richen up a little. They can be tough to adjust if the screw is still froze in. Might also be just a stuck or to strong of primary 'APT' spring. Sometimes you never know on these REMANNED carbs.
March 8th, 2020, 11:50 AM
