dme/afm question
08-25-2003, 11:12 PM
#1
Race Car
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dme/afm question
i know this has been asked before, but i neglected to look in my own driveway! i have an 84 944, and we have an 85.5 auto as well, can i change my DME/AFM from my car to the 85.5 and get a chip for the 85.5 to use in my car? if so i'll get it, if not i'll just wait on it.
tia,
-Michael-
tia,
-Michael-
08-25-2003, 11:15 PM
#3
Race Car
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No. Several minor but critical changes in the DME system. The AFS has a higher voltage and a different resistence profile. The idle bypass valve is controlled by the DME and not the heated bi-metalic spring.
08-27-2003, 03:37 AM
#6
Three Wheelin'
You don't need to change a thing. Just swap the DME and AFM. I did this to my '84, and it runs like a champ.
You can swap out the Auxiliary Air Valve and the ISV, but you don't really need to. In fact, if you go with the ISV will will have to swap the harness so you get the "diagnostics" plug for the driver side near the emissions control valves. The deal is, if you go with the ISV you need the diagnostics plug so you can disable the ISV to set the mechanical idle.
Also, the late model cars do not have the A/C air solenoid that is mounted at the rear of the air box.
You can swap out the Auxiliary Air Valve and the ISV, but you don't really need to. In fact, if you go with the ISV will will have to swap the harness so you get the "diagnostics" plug for the driver side near the emissions control valves. The deal is, if you go with the ISV you need the diagnostics plug so you can disable the ISV to set the mechanical idle.
Also, the late model cars do not have the A/C air solenoid that is mounted at the rear of the air box.
08-27-2003, 11:11 AM
#7
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oh awesome! V944god, hold that chip for me, looks like i'll be giving this a shot afterall!!! now i need to make sure the 85.5 will run okay with 84 stuff, and i'll be good!
-Michael-
-Michael-
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08-27-2003, 12:13 PM
#9
Race Director
Should work fine. My race motor is hodpodge of early and late parts. It runs fine. I use a late DME & AFM, but did use early AFM&DME as well. Just swap both and everthing should be fine.
08-27-2003, 11:59 PM
#13
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dude what are you talking about. some say yes, some say no. it DOES work, but the tach shows no movement. the car runs fine, you're a crack monkey. compatible: yes, if you change the airflow meter. there is an answer.
-Michael- just trying to find out why the tach doesnt work.
-Michael- just trying to find out why the tach doesnt work.
08-28-2003, 09:33 AM
#14
Three Wheelin'
Not sure why the tach does not work. SoCal Driver is correct that the early DME is not compatable with the late DME UNLESS you change the AFM. The DME and AFM from a late car will work on the early style car as many people including myself have done it.
08-28-2003, 10:15 AM
#15
Three Wheelin'
The late model DME and AFM does work with an early model harness, and I have a running car to prove it.
On the other hand I cannot find any reason (other than for testing purposes) for installing an early model DME and AFM in a late model car.
Exactly what are you trying to accomplish?
On the other hand I cannot find any reason (other than for testing purposes) for installing an early model DME and AFM in a late model car.
Exactly what are you trying to accomplish?