Topic: 1970 Throttle Modulator assembly

[midlife]

I have what appears to be in good shape this throttle modulator and sensor.  The modulator is marked DOAF-9E718-, dated 9H2.  It does have a cracked top plate, but is otherwise intact.  $20 plus $5 or best offer.

[JohnRB]

Hi there. Never seen this one before. What cars got it? How does it work?

Thanks

John

[midlife]

According to the MPC, it fits 302's and 351's.  I don't know alot about it, but it does mate with the 2 and 3 pin molex connectors in and around the 70 fusebox.  It gets power from a RUN-only line, and I suspect it does something to address anti-stall or emissions.  The Osborne Assembly Manual only has a deleted page showing it without part numbers.

Yeah, this is the first one I've run across in nearly 150 underdash harnesses from 1970.  I have no real idea as to its rarity or if desirable.

[WT8095]

Found a discussion of it at http://forums.vintage-mustang.com/vintage-mustang-forum/451751-70-mustang-throttle-modulator.html:

mustangsurfer:

Trying to piece together a customer car, and I found some vacuum wires I can't explain. Found out that another 70 I have here has the same thing, so I crawl under the dash and trace the lines to a small box mounted below the fuse panel.

D0AF-9A718- (nothing)

rickster:

I think I found it in my Haynes manual (P-87, Fig 3.65). It's part of the EGR system. The diagram in Fig 3.65 shows an arrow to a dotted line that encompasses three items in the diagram; Speed Sensor, Electric Amplifier and Solenoid Valve. The arrow references "Optional modulator device used on some engines". They way it looks, if I'm reading it correctly, is that for EGR systems you'd have either the EGR component trio of speed sensor / electronic amplifier / solenoid valve, or you would have the optional modulator device used on some engines. If this is the case you would need this to be hooked up and operational if you wanted your EGR system to function properly.

sidewinder:

What your looking at is the controller for the IMCO ( improved combustion) emision system. There is a plug going to the speedo's speed sensor about 1 foot from the dash conection. The vacuum lines run out to the distributor and coolant temp switch.
What it does is to retard the timing on a cold engine for emisions reasons.
You would also need the metal lines that run on the intake for a restoration. If you'd like I could email you a diagram showing the routing.

[krelboyne]

I believe that it is called a Distributor Modulator System.

Page 30 and 31 of the 1970 Mustang Electrical assembly manual.

[WT8095]

Lots of info in this thread:

http://www.concoursmustang.com/forum/index.php?topic=5959.0