Sick & Uncle Bill both have good points. I kind of lost track of this thread as I have been out of town for 3 days and Sick stated what my initial response was going to be after you had answered the questions I asked. ALWAYS check idle and vacuum in gear (2 people) with an AT. The reason for this is that you want all of your "idle settings" for when you are at a stop sign "idleing" of course. With a stick, the clutch is depressed so the car is in neutral and that is how you check idle/vacuum for MT.

Uncle Bill, I do agree with your posting about the pump cam, but I also disagree (to a point) with the "fix". Those 600's have plenty of pump cam in them (for a street 350) and the cam is for event timing and the length/time of the squirt. Depending on the position he moved it to, he may have just delayed the time or even the starting point of which the pump delivered the gas. (Don't truly know since I'm not standing there).

I think until Dad gets the timing correct (of which I believe may be the culprit) the changing of the pump cam may just be covering up the problem. It's backfiring out of the carb and I don't think it's as serious as a bad valve train(sorry Sick), but 90% of the time the carb backfires is too much fuel or bad timing. [sm=badbadbad.gif]


Dad, check the floats with the car running and if you don't already know the fuel should just be at the bottom of the threads in front and just trickling (barely) out of the threads in the back. Just be sure to adjust the floats with the car off or you'll get gas in the face. [sm=oopssign.gif] (unless you're really quick)

If you have a vacuum advance on your distributor, disconnect that and set your timing at about 12° initial (just a starting point) and if you have a timing light with a dial on it check the timing at 2600-3000 RPM. It should be around 34-36° total without the vacuum hooked up and not going any higher after 3000rpm. 36° is just a good baseline that a lot of engine builders/tuners use to start at. 1-2° either way may be better for your engine combo, but 36° will work well enough to get you started and it will eliminate the timing being part of the problem. After you do that, put your pump cam back in the original position and let us know how that worked.

Of course, I could just be pulling this out of my A**, but I still feel that the timing is the main culprit. If it isn't, at least it will be closer to where it should be and you WILL see some performance gain after the backfiring is corrected.

GET THAT TIMING ADJUSTED.....

RM

 

Well, I tried the timing, that did not help
The pump cam has done the most good
But when the light turns green and you mash the petal to the floor you still get cough putter putter, hesitate, go
If you ease into it past the hesitation,varooooom away you go!!!