To pull or not to pull?

[golfbuddah]

Hi guys,
looking for ideas on poor running 1973 2.4 with webers. I have spent a lot of money with 2 Porsche specialty shops trying to get this running well. Scoop is I have no history on engine. 6133926
Here is what has been done
Full tune up with new parts including pertronix ignition, wires, plugs, cap, valve adjustment, fuel filter, fuel pump, rebuilt distributer(no place to put vacuum advance hose on carbs.
R&R carbs, new air filters, removed, planed intake manifold and phenolic spacers. removed jets(165 main) and cleaned carbs. synched for the third time. when we removed intake we noticed some porting work had been done.
The only time the car ran well was after I removed the plug wires and cut the bad wires back and reconnected the ends. Alas the fuel pump died, and the aftermarket wires plugs and pump were put in. car now back fires and misfires again.
Could new wires be defective out box?

One expert wants to buy a bunch of main jets and experiment, the other wants to pull the engine to see what cams I have? Is there any simpler way.

[Eagledriver]

You could try the old wires again. New wires could be connected wrong. Most likely need to tune the carbs. If you are worried about the engine itself you can do a valve adjustment and a compression test. If these are good then the engine is good (at least as far as running smooth). The idle circuit does 90 percent of the work on these engines. The main circuit only comes into play at full throttle and almost full throttle. A wide band O2 sensor makes tuning much easier.

-Andy

[al lkosmal]

Since it was running nicely before the fuel pump died, why would you try new jetting and worry about the cams? I don't follow the logic. Did your 911 run good before or after all the ignition and carb work? Anyway.....I'd try the easy stuff first. Double check to make sure that the plug wires are plugged into the right distributor connections, ....1 to 1, 2 to 2, etc. (sometimes it's the easy stuff that gets overlooked or goofed up) Did you try your old wires to see if the problem went away? . Do you have the fuel pressure dialed in to 3-4psi for the Webers? Clean all the jets again. Check for vacuum leaks, etc. Is your distributor advancing properly?....After that you're back to square one... methodically going through the timing, Valve adjust, carb setup, etc. Is it backfiring through the carbs or muffler?

[golfbuddah]

Went into shop for misfiring and backfiring. did all tune up work except wires cuz i had some on order. it was still backfiring through both intake and exhaust. the new wires came in and i tried to install but they had wrong connection for plugs so I put the old wires on after cleaning up connectors. started and ran fine then the fuel pump died. brought it to shop to do pump, new wires and new plugs. ran ok on test ride with mech then started spitting and sputtering and he did carb work. he says cams had to be changed with carb mod. he said he needs the cam lift and duration to tune the carbs properly. I will check firing order tomorrow. comp is 155-165