93 econovan new carb and head has air leak where else to look .new carb is webber so only runs advance hose and fuel inlet hose but if i cover the carb by hand idle,s properly

It could be a few things, but my guess is a fouled spark plug. This could also be a sign of a bad ignition coil, clogged air filter or something wrong with the air sensor, or a major issue like a leaky head gasket. Start with the easy stuff like the air filter and the spark plugs. Also, try to borrow or pay someone to read the fault coded with a VAG-COM, at the very least it will tell you which cylinder is misfiring.

Sounds like a vacuum leak. Spray carb/throttle body cleaner at all fuel and air intake areas ie; intake manifold to heads, throttle body to intake, all vacuum hoses, etc. Work the throttle to keep it running or have someone inside doing it. You will know if the carb cleaner gets sucked in somewhere. That will be the location of your vacuum leak.

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I would start with checking the fuel pressure and boosting the fuel with spraying carb cleaner into the air intake hose.
It sounds like you are not getting enough gas into the cylinders.
Could be a vac leak too.

Check compression test minimum 125 psi and above with gas pedal down check fuel pressure and ignition timing, check idle speed valve PCV valve is on top of your rocket cover with a hose going to inlet manifold by hose vacuum hose leaking or loose .air filter ,or exhaust blockage .

change main jet in the carburettor install K&N air filter and iridium NGK or DENSO spark plugs tune up your engine change oil filter and oil. Flush your radiator check tyres pressure, Check engine compression and air leaks from inlet manifold ,Run hi octane fuel and injection cleaner mix for 250k to clean the carbon in the cylinders ,check for fuel hose loose ,carburettor leaks,distributor cup aluminium contacts to be clean, Vacuum hose on distributor unit for suction for advance timing .

Not sure which design carb you have but here's a rule that works for all carbs. Attach the vacuum advance hose to any port coming from the carb baseplate (bottom). If you don't have a free one, you can use a "T" in another line or if there's a fitting on the manifold you could use that as well. Just make sure that the line has full vacuum at idle. (check with a vacuum gauge or just put your finger over it and feel for vacuum) Since it's pretty old, it would be good to put your finger under the advance mechanism when you attach the line (running) and make sure the small rod that goes into the distributor moves when you do that. if it does not, then the advance diaphragm is bad and you will need to replace it. Use small rubber plugs to block off any unused ports.
As for the fuel line. You should have a threaded inlet on the fuel bowl. The line attaches there. If you need to make a line, you can get one from any parts house, cut it to length and use rubber fuel hose to join it together with the one already on the fuel pump. When running new line, keep it away from exhaust manifolds, belts and pulleys. Best to put an in-line filter in the hose....that will keep the carb clean. If it's a four barrel (doubtful for that engine) you would need a fuel rail that joins both carb inlets to the single line from the pump.
If you have a problem understanding this, just ask and I'll clarify it for you.

2nd hose is for you positive crankcase ventilation(PCV) valve hose....(like a breather hose)

Pretty sure I have the diagrams etc but they are buried away and would take a week to find.
BUT: The setup on that engine for that year is fairly uncomplicated and you could pretty much do away with all the emission controls etc and get the engine running really well. (just block off all vacuum ports on the manifold and carb except for the one to the transmission and power brake booster) I'm not really familiar with the edelbrock carb (looks like they are based on the old carter AFB carb though. I am partial to holley carbs, and the old quadrajet carbs)
What you need to check first though is your fuel pressure and delivery. You should be seeing 5-7 psi at the carb. With the fuel line disconnected, and attached to a rubber hose diverted into a container, you should see at least a gallon of fuel pumped at idle before the carb runs out of fuel. Make sure you don't have any leaks in the fuel line coming from the tank...with a pull type pump (mechanical pump on the engine) a leak often will not drip, but will allow air to be drawn into the line while running. Make sure that if your carb has a filter in the fuel inlet, it is clean. Make sure that the fuel line filter (sock) in the tank is also clean.
It's likely you have an egr valve on the manifold, If so, you can temporarily block it off with a small piece of metal from a soda can installed between the valve and the manifold. That will prevent it from working and if it has any leaks, blocking it off will eliminate it from the system. If that helps, replace the valve.
Your ignition system is fairly simple. a single 12 volt lead goes to the battery side of the distributor. You can block off the vacuum advance temporarily and just set the initial timing at about 8 degrees advanced. (depending upon fuel quality, you can go as high as 12) . The ignition module is not "testable" usually though they either work or they don't )
You do need to check the wires that attach to the pickup under the mount plate to make sure they are not partially broken and grounding when the advance moves the plate.
Back to your carburetor... If you are test driving without the air cleaner housing in place, it is possible that if there is a heat pad mounted to the underside of the hood, it can get drawn down against the carb inlet and cause problems. If the air cleaner housing is in place, make sure that the inlet door in the snorkel is opening or, disconnect the vacuum hose going to it as default on those is wide open. If you have tried everything I've outlined, you may have to go inside the carb and make sure that the power valve isn't frozen or that the float level isn't set too low.
Once you get it running right, you can begin to look for the diagrams etc you are looking for, but at least it will be running and usable.
The only other item that could give you a problem like the one you have is if the cam timing was set incorrectly at the factory (doubtful but it can happen) but I really would not worry about that just yet.
Hope something here helps!!! Good luck!

sounds like a leaking inlet valve broken valve spring/ faulty valve/lifter prob. or a worn out camshaft if the exhaust cam has worn out the compessed gas cant escape so when the inlet valve opens the internal cylinder pressure blows back in to the inlet maifold if it was me i would do a cylinder compression test first that should help you to isolate the cylinder thats at fault

As far as I know without checking it personally it sounds like it could be one of three things (in order from easiest to hardest). Clogged air filter, worn timing chain, leaking head gasket. To check for the third go to Auto Zone and get them to do a compression check, its free. I can't remember off hand but if the 93 has a TPS (throttle position sensor) that could also cause an irratic idle.