I meant that the engine was loping ,revs to about 1200 then almost dies,revs-dies, revs-dies, revs-dies
Ahhh, now it sounds like you've got a vacuum leak, possibly between the throttle body and the air flow meter, or your air flow meter is junk.
That's cool that you're carb and your helping out your buddies efi. Efi's are pretty cool and its always nice to learn about 'em. Kind'a the same way with me, I dont know jack squat about how to trouble shoot carbs and I wish I did.
The term 'loop' is actually a programing term that we use to describe the behavior of the computer itself. Before the engine warms up, the computer is in what we call "Open-Loop Mode" where it is monitoring all sensors and checking out the air temp and oxygen content, etc. Once the engine warms up, the engine revs down to normal idle, and this is because the computer has just switched into what we call "Closed-Loop Mode". Now it is operating within a preprogrammed set of preferences with considerations for optimum power, gas mileage, and lowest smog levels.
So when something like a sensor is really screwed up, the computer will stay in Open-Loop mode because it sees a problem and will not operate normally and will avoid closed loop mode. So the power would be off, the mileage would suffer, emissions could be worse...... basically the computer waits for a 'all systems go' condition before it runs closed-loop mode and before it's gonna run normal.
Sounds like a barrel of fun doesnt it?