1972 914 with '74 2.0L

The Problem:

Car is hard to start. It backfires through the carb on light accel. It backfires through exhaust on decel. And it idles very low and wants to die after stopping. Runs fantastic on wide open.

The Facts:

Weber 40IDFs (freshly rebuilt and tuned, ran great for about 500 miles)
Freshly Rebuilt engine (ran fine for around 2000 miles)
All new ignition system (distributor, plugs, points, wires)
Newer Tarret Fuel Pump (front mounted)
Rubber fuel lines from tank to engine (not OE)
Checked the valves, they're fine.

Questions:

Could It be low fuel pressure,
Degrading fuel lines,
Timing issue,
Vacuum leak....
I'm at a loss currently.


Lets hear your thoughts and experiences.

Thanks
Chris

Chris. Do you know if the carb linkage is opening both carbs at the same time equally and smoothly? Take a deep breath. Take it one step at at time. I've been there before. Trust me! New anything doesn't mean anything to me anymore. I recently installed new points and a condenser on my car and both went bad within 100 miles! If it were me I'd look at the linkage closely. If you know that's good. Check for good spark. I always carry extra points and condensers. Easy to swap them out just to test. Same thing with the coil. Once those are eliminated as possible suspects. Adjust the valves. Still problems? Maybe do a compression check. Still problems? Maybe blow out the idle circuits on the carbs? No fuel injection to diagnose so for me this would be easier.

"Vacuum leak..."

Hold it at slightly elevated idle (I use a popsicle stick behind the master carb lever)
Take some engine cleaner or carb cleaner and spray it around the intake manifold bases (where they go into the heads), carb bases, and carb shafts.

See if the engine bogs

It sounds like you have one or two plugged idle jets.