Jared944

Now wait....... according to Todd's wiring changes, pin # 7 next to the brake booster is term 85 for the 968, and 12v during starting on the 944 side. I just cut both leads...... If I grounded the term 85 lead, would it help?? Maybe I should run a totally new lead from the DME relay to pin 7??

Jared944

Ok..... I ohmed out pin#1 on the DME to the green lead on the coil, and came up with a resistance of .2, which is descent continuity. Looking at the Todd's wirig changes, the ignition coil is pin # 1 next to the brake booster..... I ohmed out this pin and DME pin #1 and got perfect continuity.

Jared944

Ok.... I went ahead and connected term 85 from the DME relay to the #7 pin on the brake boost connection. Still nothing :P

kevin Dubois

(sorry, i am trying to take care of some other stuff quickly while i review the diagrams some more...) you don't have to wait for me tonight if you don't want.

Jared944

Im looking over the wiring schematics myself, looking for any possible solution. Ill probably be up for a while tonight

Jared944

If your going to crash for the night, drop me an email later if you have any input...... thanks for your help so far!!

speedracing944

jared944 are you documenting the process? What were the road blocks you have run into? I am looking at the same project as you for my 83.

Speedy

Jared944

Yep I am. The problem is that the conversion is a LOT OF WORK of an early 944....

Anyhew - I grounded out term 85 and 85b.... and the fuel pump runs when the key is turned to start!! However, I am still not getting any spark. I have +12 volts to the coil when the key is turned to start, but no spark. I don’t really understand what the alarm system does when it is activated.... I pulled the +12 volt lead to the alarm pin leading to the DME (Pin # 7 in the passenger footwell), and I still get +12 volt to the coil.

So, here is what I figure. Either A) The alarm is still killing the ignition sequence somehow, B) the coil is bad (I have 2 used coils laying around, and tried both of them), or something else. What is the "Hall Sender"? Its that little sensor behind the cap, next to the timing belt. Could that be the problem?


Thanks!!

Jared

Tom Carson

IIRC the alarm turns off the fuel pump when activated.

if the "Hall Sender" is not working the 968 Motronics retards the spark by about 6 degrees...but the engine would still run.

from what I posted to you earlier (another post):

"Jared, Todd's chart is good to use...even for your ‘early’.

the big difference is the connector by the brake booster, the 'lates' and the 968’s have a flat rectangular shaped black 14 pin while the 'earlys' have a cube shaped white 9 pin Molex.

so you may need to splice and crimp these wires or replace a plug/connector end.

find this Molex connector by the brake booster on your car and you’ll see pin #:
1 – green
2 – red/blue
3 – red/yellow
4 – black/green
5 – black/gray
6 – black/white
7 – red/black
8 – blue/yellow
9 – blue/black

the colors and function of each appears to be the same (btw...968 pin#1 is white which connects to 944 pin#1 green, and 968 pin#9 is blue which connects to 944 pin#9 blue/black, but functions are the same).

the function of pin #7 is very different. if I read this right…according to Todd, cut pin #7 wire (red/black) and leave ‘open' to prevent the 944 from sending +12volts into the 968 DME computer when the key is turned to 'start' or key postion '2' (this goes to the DME relay & the 944 has a chassis ground already in place so it is not needed). and the 968 DME does not need a +12v when 'starting'.

also run a new wire from the ignition key switch ‘15’ black (+12volts in the ‘on’ or key position '1') to the red wire in pin #12 (red) of the 14 pin connector.

besides that pin #12, on the lates/968’s 14 pin connector, you also have pin # 10 - a high temp idiot light - that has no where to go."

did you make and/or cut these connections?

did you "run a new wire from the ignition key switch ‘15’ black (+12volts in the ‘on’ or key position '1') to the red wire in pin #12 (red) of the 14 pin connector."

dualblade

jared, check your email

Jared944

Yea, I did all of that. However, instead of just cutting pin#7, I ran a wire from term 85 from the back of the DME relay (like the 968 schematic has)

It seems that term 85 (pin # 7) and term 85b (pin#5) were not getting a correct ground signal. I spliced in a connection from the ground to both, and the fuel pump started working.

I had pin # 12 connected to term 15 on the ignition switch, but changed it to term 30 because the DME connection said "term 30"....

Other than those modifications, I connected everything perfectly.

Jared944

WAIT.... I just shot the coil again. I disconnected the positive lead from the DME, and turned the car to ignition. I read +12 volts to the coil from the DME, but only +2 volts from term 15 (the negative side of the coil). Shouldent I be getting 12 volts??

Tom Carson

hmm...you're right "term 30" which has 12V all the time (not switched). prolly should have an in line fuse on that...maybe sized around 8 amps

good to know that pin #7 wire that goes towards the DME relay needed to be grounded...Todd made it sound as if this relay was already grounded somewhere...wonder if Matt O. tried this?

how did you bypass the alarm?

Tom Carson

yup...both (low voltage) sides of the coil should have 12volts. the green wire should have a 'pulsing' ground from the output stage of the DME. sounds like you have a 'permanent' ground

either a bad (shorted) switching transistor or something in the alarm system…dunno much about the 968 alarm but many aftermarket alarms put a ground on the coil to keep it from pulsing a spark

Jared944

Well, I ran a leed from term 15 straight to the negative side of the coil. So, I get +12 volts on either side, but I still DONT GET A SPARK. Im going to go nuts.

I bypassed it by grounding out term 85 and 85b (pin 7 and pin 5). The fuel pump will run, but no spark.