Volvo Repair: Volvo 1979 264, air flow meter, fuel pumps

Question
We have been having problems lately with our '79 264. At first it would start great off the bat, but then you would get stranded until it had sat and gotten cold. This is our 4th Volvo, and my husband works on ours when needed. We at first checked both the fuel pumps, and we have dropped and changed out that small fuel like sock going into the inner fuel tank. Later we ordered a new fuel relay [the thingee under the dash by the steering column] and it ran fine again for almost a month. Now, it is right back to where it started, but the fuel relay is clean and working fine. After much reading this weekend, and tinkering we have had the same problems again. Will start, and run great but if you go off somewhere it will not want to start. My husband has checked the oxygen sensor [the car starts with or with out it hooked up], and replaced all the relays on the inside wall of the front fender by the battery, and the water tank.  

It will start everytime if he removes the plastic cover on the top of the engine, and gently presses the air intake thing open just a tad more...to let more air in at start.

So he wonders how to set [or reset] the air flow meter. Where is the switch that provides voltage to the air flow meter....as maybe that may need replacing?

We have been at just about everything we found in our manuals, and online @swedishbricks and are very frustrated.  

Answer
this is an old CI fuel injected engine which I have not worked on many.I have seen others work on them and they seem to be difficult when it comes to getting them to run right.by time they run bad there is usually more than one problem.this flap is adjustable with an allen wrench ,but it may need adjusted to help it run due to another problem.the best thing would be to have it looked at by someone familiar with the older cars.sorry I could not help more.