Late DME and AFM in early 944
#1
Rennlist Member
Thread Starter
Late DME and AFM in early 944
I have a DME out of an 87' 944 and a AFM out of an 88' 944. I want to put these in my 84' 944 but I read that the late DME's will not fire the fuel injectors due to the different drivers.
This was on Clarks Garage: "Just realize that you can't test an early 944 (pre-1985.5) using a DME computer from a later car or vice versa. They use different injectors. A later DME will not fire early injectors at all. An early DME MAY fire the injectors in a later car but, the current draw will be excessive and you could potentially damage the DMEs injector drivers. Even if you don't damage the injector drivers, they will likely shut down after a few cycles due to the excessive current draw."
I know some of you have done this swap for a later DME and AFM into an early 944 have you had these problems?
TIA!!
This was on Clarks Garage: "Just realize that you can't test an early 944 (pre-1985.5) using a DME computer from a later car or vice versa. They use different injectors. A later DME will not fire early injectors at all. An early DME MAY fire the injectors in a later car but, the current draw will be excessive and you could potentially damage the DMEs injector drivers. Even if you don't damage the injector drivers, they will likely shut down after a few cycles due to the excessive current draw."
I know some of you have done this swap for a later DME and AFM into an early 944 have you had these problems?
TIA!!
#2
Lazer Beam Shooter
Rennlist Member
Rennlist Member
You can swap the DME and AFM.
The Early DME's (pre 85.5) have to go with the earlY AFMS. It uses like a .5 volt signal instead of a .9 volt or some crap like that.
Ive swapped out the DME and AFM from my 86 into the old yeller 84. It worked.
You just have to switch both! The later AFM/DME setup allows you to use chips that can be dropped in, whereas the early DME's chips have to be soldered in.
The Early DME's (pre 85.5) have to go with the earlY AFMS. It uses like a .5 volt signal instead of a .9 volt or some crap like that.
Ive swapped out the DME and AFM from my 86 into the old yeller 84. It worked.
You just have to switch both! The later AFM/DME setup allows you to use chips that can be dropped in, whereas the early DME's chips have to be soldered in.
#4
Rennlist Member
Thread Starter
Awesome Rock, I knew the later AFM was required for correct signal to the DME. I am glad to hear no problems with the injectors not firing.
In regards to the O2 sensor did you have to use the later heated style? Right now mine is unplugged because it does not have that much authority (0.25V - 0.75V) and actually runs better.
I am hoping this will help with my intermittent no-start problem. I think my early DME's are suffering from cold solder joints. I have to open them up and look where the ribbon cable connects the two boards (source of probs) and by the transistors as well.
In regards to the O2 sensor did you have to use the later heated style? Right now mine is unplugged because it does not have that much authority (0.25V - 0.75V) and actually runs better.
I am hoping this will help with my intermittent no-start problem. I think my early DME's are suffering from cold solder joints. I have to open them up and look where the ribbon cable connects the two boards (source of probs) and by the transistors as well.
#5
Lazer Beam Shooter
Rennlist Member
Rennlist Member
Originally Posted by Charlie944
Awesome Rock, I knew the later AFM was required for correct signal to the DME. I am glad to hear no problems with the injectors not firing.
In regards to the O2 sensor did you have to use the later heated style? Right now mine is unplugged because it does not have that much authority (0.25V - 0.75V) and actually runs better.
I am hoping this will help with my intermittent no-start problem. I think my early DME's are suffering from cold solder joints. I have to open them up and look where the ribbon cable connects the two boards (source of probs) and by the transistors as well.
In regards to the O2 sensor did you have to use the later heated style? Right now mine is unplugged because it does not have that much authority (0.25V - 0.75V) and actually runs better.
I am hoping this will help with my intermittent no-start problem. I think my early DME's are suffering from cold solder joints. I have to open them up and look where the ribbon cable connects the two boards (source of probs) and by the transistors as well.
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#8
Three Wheelin'
Originally Posted by Charlie944
Anyone know if later 944 Fuel Injectors will fit into a early 944 fuel rail? As far as nozzle sizes are concerened.
#10
Nordschleife Master
Originally Posted by 85944na
I'm running a late dme/afm with early injectors, haven't had any problems. I have not heard of the injector issue before do I need to go out and get some injectors?
#13
so u guys say that u cant run with a late DME and a early AFM..right??then can someone tell me if i can adjust mine AFM (i have a 85.5 car) because when i bought the car someone has opened the AFM and relocated the spring...can i know somehow what is the right position for it??or i have to get another one(new it's out of the budget ,and used..i cant find ) ?? ...pls help me ,if someone know....i have a very big fuel consumption..and im sure it is because of the AFM
thank u
thank u
#14
Nordschleife Master
No, only late with late and early with early (DME/AFM).
#15
Nordschleife Master
Originally Posted by M758
my 84 944 has run from the start with Late AFM/DME/Injectors. For time I ran early AFM/DME with the same late injectors. Never any issues.