POOR RUNNING 82 FI SPIDER

[rlux4]

Are you saying that the flap isn't moving as the engine is running? If that's the case, but you can move it by hand and it doesn't feel sticky, it sounds like it has too much tension on it. The tension on the flap is spring controlled by a spring whose tension is set by a geared wheel. It can be adjusted (you'd want to "relax" the tension on the spring) but be sure to mark it's current position. But keep in mind that you may be opening a can of worms. Personally I'd prefer to subsistute a known good AFM to see if this is your problem.
Ron

[So Cal Mark]

I'd advise against tampering with the spring tension in the afm

[rlux4]

I hope I wasn't misunderstood as advising changing the spring tension. My last two sentences were meant to give the same advice you're stating Mark.
I guess a better way to have put it is if the flap is not moving while the engine is running, and if it's not sticking, then the AFM sounds like it's toast. If that's the case it would have to be changed out anyway, so as a last resort before going to the expense of a replacement AFM it wouldn't hurt to see if the flap would move with less tension. It would affect fuel mixture ratio though, to be sure.
Ron

[So Cal Mark]

I'd check both cam and ignition timing first, and make sure the catalyst isn't plugged. It doesn't sound like an afm problem to me unless the flap is stuck

[ARNO]

Hi
The AFM flap only moves a small amount when the car is running,there is no air leaks at all.So i let some of the tension off the spring 8 notchs and now when you rev the car the flap moves too and the car revs fine its almost like the engine was,nt pulling the air strong enough to open the flap in the same ratio as the throttle plate,so now i have to get the fuel set correctly.
Could the geared wheel have moved or is the AFM faulty and i am just maskong the problem..

Many thanks Arno

[rlux4]

That's great Arno. Good call keeping track of how many notches you adjusted it. It does seem strange that the spring tension would increase with age, usually if anything it would decrease. What shape is your air filter in? A very dirty air filter will inhibit air flow.
Ron

[So Cal Mark]

I would guess that the afm had previously been tampered with if the spring tension is wrong