RE: How To Test A 75TS AFM?

[Nilsson Anders L <Anders.l.Nilsson@xxxxxxxxxx>]

Hi,

I'm experiencing about the same problem as you do. It has so far been a
nightmare to track down. Everything I've tested seem to work fine :-(

> I am still trying to track down a sluggish acceleration 
> problem on my 75
> twinspark. Can anyone tell me how I can test the air flow 
> meter? I have
> tried a multimeter on the unit to measure the resistance and 
> manually moved
> the airflow flap. It appeared to have a linear resistance 
> increase up to a
> certain point, but then the resistance went funny for a bit and then
> decreased in resistance as the flap was moved further. Does 
> anyone have an
> idea of what the resistance range should be like?

Been there, done that :-)
Thing is, you have to have it connected with ignition turned on. Then you
measure voltage between the connectors. It should change in a linear
fashion.


> 
> Also, a stab in the dark. The engine is running very cool 
> (approx 60 degrees
> Celsius when fully warmed up) according to the temperature 
> gauge and I think
> either the temperature sensor or the thermostat is faulty. 
> Could the engine
> running cooler or the temperature sensor upset the engine 
> management system
> and possibly cause this sluggish problem?
If it's the thermostat, I think it will still run pretty well since the EFI
can adjust for a true temperature.
If it's the temp. sensor, I think the EFI would adjust to the slightly rich
side. I'm not sure of this, but I think that the air/fuel mix difference
between 60 deg and 80 deg is too small to cause a noticeable "sluggishness"
(sp?)

> 
> The odd time that the engine doesn't accelerate sluggishly, 
> the old girl
> (152k) gives you a decent kick in the pants, so I know it has 
> it in her. Any
> help with this problem would be greatly appreciated.

It is always interesting? to start her up in the morning and see which mood
she is in today, bears some resemblance to the female sex, doesn't it ?  :-)


/Anders Nilsson
- -90 75 2.0TS with 174.000km and rolling

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