FS:1988 944 DME/AFM $300 US
12-17-2016, 12:03 AM
#17
Rennlist Member
Here's the skinny on the altimeter and the tach signal...
Altimeter plugs into the harness, right off the loom coming out of the DME. 85.5+ harnesses simply don't have this branch. You can run the early DME without it with no ill effects. So, non-issue.
The tach output is exactly the same across years, in fact, the tach triggers from the coil ground (DME pin 1). Another non-issue. As posted above, the only thing to keep track of is that the AFM matching.
Your issue with hard starts sounds fuel related. Have you verified the position of the FQS on the early DME? Perhaps the previous owner fiddled with it, and now it's too rich (throttle needed to start car). Maybe the FQS is ignored during cranking, but I'm not sure. The air temp sensor in the early AFM could also be going out, providing false air temps to the DME. There are tests on Clark's garage.
Altimeter plugs into the harness, right off the loom coming out of the DME. 85.5+ harnesses simply don't have this branch. You can run the early DME without it with no ill effects. So, non-issue.
The tach output is exactly the same across years, in fact, the tach triggers from the coil ground (DME pin 1). Another non-issue. As posted above, the only thing to keep track of is that the AFM matching.
Your issue with hard starts sounds fuel related. Have you verified the position of the FQS on the early DME? Perhaps the previous owner fiddled with it, and now it's too rich (throttle needed to start car). Maybe the FQS is ignored during cranking, but I'm not sure. The air temp sensor in the early AFM could also be going out, providing false air temps to the DME. There are tests on Clark's garage.
12-17-2016, 07:49 PM
#18
Race Car
Thread Starter
Thanks Odonnell, was hoping to hear from you also.
Well, I put the 88 stuff that Jeff was buying & the car drove perfectly, all gauges working & no drama. The "other" ecm appears to have had some exposure to water & appears to have been opened a time or two. Before installing the dme I popped the seal off to ensure that it had a FQS switch. That plug was so secure that I doubt it had been messed with.
At this point I'm just assuming the ecm is nearly garbage, but I'll hang onto it as an emergency spare.
Well, I put the 88 stuff that Jeff was buying & the car drove perfectly, all gauges working & no drama. The "other" ecm appears to have had some exposure to water & appears to have been opened a time or two. Before installing the dme I popped the seal off to ensure that it had a FQS switch. That plug was so secure that I doubt it had been messed with.
At this point I'm just assuming the ecm is nearly garbage, but I'll hang onto it as an emergency spare.