Where to get EEC-IV ECU specs/schematics.

[ARTHUR OKUN]

You wrote: 
>
>>> I am pretty sure I trust the mechanic.  I tested the EGO myself and 
was 
>>> getting ~0.53V from it.  I disconnected a vacuum line and got 
~0.68V fro 
>>> the EGO.  On top of that, I have tried 4 different EGO's, 2 new 
ones, and 
>>> two junkyard ones, and still a code 41.  I have had this code 41 
for 
>>> about a year now and have been trying to trace it for almost as 
long.
>>
>>Larry Harris  lharris at crl.com  (770)682-8842 (voice) answered:
>
>>Since you are talking about EGO's in pairs, I assume the car is a 
>>Mustang. 
>>
>Not Necessarily..... 
>My Ford 85  mid-sized (notCrown Vic. )  LTD with a 3.8 V6 and CFI ALSO 
has
> 2 EGOs, and  ALSO has  KOER codes of 41, 43, 91, 93 constantly  - the 
EGO
> on the left  (US driver) side  seems to drift around but tends to 
stay low
> voltage == lean. Curiously enough, the V8 (5.0L) only has 1 EGO.....
>
>
>>From what I've read in HOW TO TUNE AND MODIFY FORD FIJ SYSTEMS (the
>exact title is available on the DIY WWW server) the sensors can be 
contaminated
>by silicon from engine sealers, causing them to claim lean.  Is your 
sensor
>actually
>switching?  The computer may be counting transitions from lean, not 
the voltage
>itself.   
>does anyone know how long it takes an EGO to Silicon-foul? 5 minutes? 
5 weeks?
>MASMITH 
>(profession is rocket engine physicist . An engine is just 2  very 
large
>fuel injectors...:-)
>i applogize for typoes but am balancing 2 month old on other arm.....
>
>
>could just be a bad solder connection on the computer printed circuit
board this is quite a common problem with consumer electronic equipment

you might be able to trace the problem on the circuit card with a
low test voltage digital volt meter

a friend of mine actually found a dead insect inside an unsealed
chrysler ecu that was shorting across something causing intermittent
problems