I have a 1990 ford f150 with a 4.9 6 cyl. engine. It was taken apart to replace the fuel injectors, no vacuum lines were labled. I have a thermactor air diverter solenoid that I cant' figure out w

plug, plug wire, coil or igniton module. Check for vacuum leaks.

Have u checked the cadeletic converter. It can do funny things

intake manifoold leak check all vacuum lines replace all vacuum lines if look cracked ,spark plugs could be fouled out by leaking fuel injectors, clean fuel injectors,replace fuel filter,replace air filter,replace spark plugs and wires,do tune up see if it helps if not.could have leaking intake manifold gasket or leaking egr valve,use engine vacuum gauge check engine vacuum for intake manifold gasket leaks.

A mechanic would check the injectors for voltage and for a ground signal from the computer.
The injectors get power from the EEC relay near the battery.
The ECM computer gets a signal for the coil and the injectors from the module mounted on the side of the distributor.

There was a diagram under the hood from the factory of the hoses. We do not have the diagrams.

First thing and the cheapest thing to do, is change your fuel filter.

Change the intake manifold gasket, that means taking the whole top part of the engine apart.

You will not see any vacuum from the egr solenoid until the engine has reached normal operating temperature and certain other driving conditions have been reached (like throttle position and road speed). If the engine runs rough when warmed up, check the CTS (coolant Temp sensor) when hot and cold and if no fault shows there, start checking input sensors for engine and cam position, engine timing, RPM etc. If the EGR valve was leaking, it is only adding air to the exhaust stream and usually, manually opening the valve and blowing out the seat with compressed air should fix the issue. This can also be an issue with clogged injectors. When the engine is cold, fuel enrichment supplies more then normal fuel amounts to encourage even running. When the engine warms up (normal operating temperature), fuel enrichment mode is turned off. If your injectors are clogged (even if only slightly) fuel starvation will cause rough running. Fuel enrichment overcomes the starvation of clogged injectors. Try adding a propriety injector cleaner to your fuel tank and watch for an improvement. If you do see an improvement, have your injectors cleaned and tested professionally. If you locate any other issues with engine sensors, replace them and ensure the new components are adjusted correctly if required..

I had a geo metro that sat a long time and the gas turned to varnish. You will need to drop the tank, clean out the gunk, put in a new fuel pump and and filter and flush the fuel lines out to the injectors.

Just a suggestion, but get a fuel pressure gauge and check your pressure regulator.  They use intake vacuum to control a diaphram that regulates the fuel based on RPM/vacuum relationship.  I had a Supra with a similar problem - had all the mechanics stumped.  It was flooding in #1 and # 2 cyl. badly.  Turns out rubber diaphram in pressure reg. cracked and the engine vacuum was pulling gas directly into the intake manifold on top of what the injectors were supplying!  Also, lifting the regulator's vacuum line off the manifold and holding it close to the vacuum, you'll actually see gas getting sucked in if that's the problem.  I took the same route you did, replaced inj. etc, before I stumbled on this.  Good luck!