other Lurching Under Steady Throttle

[Beach_Bum]

The car feels like it's jumping forward while driving at a constant speed. I notice it most in 3rd gear between 2500-3500 RPM, but it also does it in 4th gear on the highway at around the same RPM. I've also noticed a slight hiccup at wide open throttle, but not sure if this is related. It idles well at a pretty steady 1k RPM.

 

It's done this since I picked up about a month ago. Everything is pretty stock. It has a Solex carb, but I'm not sure which specific model.

 

Things I've done since purchase:

Changed spark plugs: NGK BP6ES

New Bosch Distributor Cap

New Bosch Rotor

Changed oil/filter: Mobil 1 15w50 & OEM Filter

Added valve cover breather hose

Added pre heater hose from exhaust to intake

Added the FAQ Intake block off plate

 

Should also state that the fuel pump "looks" new, and was supposedly replaced by the previous owner, and that I'm running 93 octane gas.

 

Thanks for your help.

Edited August 23, 2013 by Beach_Bum

[TobyB]

Unfortuantely, it could be one of 2 things- timing or fuel.

 

Which, of course, really narrows it down.  If the distributor's mechanical advance

is worn out, it will let the timing wander- and you'll lurch.

 

If you have an air leak, it'll lean out the carb- and you'll lurch.

If the fuel line's leaking air, it'll suck air, and lean out the carb...

If your fuel tank's got junk in it, it'll lean out the carb....

 

well, you get the idea.If it was me, I'd do a general clean- up,

throw a timing light on it to see if it's steady, put a low- pressure fuel

gauge on it to make sure it's getting gas, clean out the carb float bowl

and then start looking for other tell- tales to see if they can help you find the problem.

 

fwiw,

 

t

[Beach_Bum]

Thanks for the advice. I'll get in there this weekend and see what I can figure out. I'll have to read up on how to perform some of these tasks, since I'm new to older cars.