Emissions Computer 89550-60130 (1 Viewer)

[Engineer8000]

I spent some time in the shop reverse engineering this module and drew up the schematics for the different functions. It has two proprietary ICs on it, one that handles RPM and one that handles the speed sensor and temperature sensor. These turn various transistors on and off to perform the required functions based on speed, rpm, OC temperature and vacuum. I was able to determine the signals required to simulate the speed and rpm inputs and the resistance of the OC temperature sensor at its setpoints. This one works, kindly provided by @Spike Strip to get this effort off the ground.

Testing

 

[OPMACHINE]

 

[Spike Strip]

Wow. Are you Tony Stark?

 

[db3]

Years ago I had to repair a 76 Federal unit so I could pass the CA smog test.

 

[Engineer8000]

That is interesting, the module I have (89550-60080) for 76-78 only looks at vehicle speed to turn on the evap vsv. You have a lot more going on in your schematic. That looks like a Cali unit with the throttle switch and all. Thanks for sharing.

 

[Engineer8000]

Wow. Are you Tony Stark?

Barney Collier

 

[db3]

That is interesting, the module I have (89550-60080) for 76-78 only looks at vehicle speed to turn on the AI vsv. You have a lot more going on in your schematic. That looks like a Cali unit with the throttle switch and all. Thanks for sharing.

Unfortunately I didn't note the module part number, and cannot read it in my photo. It could well be a CA unit. When I purchased the vehicle, I had to reconstruct the entire smog system, as it had been cobbled together from mismatched parts from various years when it was brought into CA from Colorado. It was challenge, to say the least, but I did manage to successfully pass the smog test.

 

[db3]

I have (89550-60080) for 76-78

Are you collecting modules? I have a 89550-60100, which I believe is for a 78 Federal system. The guy I bought it from was replacing the 2F with a SBC, so I purchased the engine and all the smog components. If want it, PM an address and I will ship it to you.

 

[Spike Strip]

I just mentioned in a message to Engineer8000 people often don't realize how a malfunctioning Emissions effects drivability, let alone smog testing.

I put a NOS box on my truck a few years ago, when I had both idle problems and backfiring, and all the problems went away, and I could then see on the A/F meter the fuel decel circuit working when I let off the throttle.

 

[db3]

I just mentioned in a message to Engineer8000 people often don't realize how a malfunctioning Emissions effects drivability, let alone smog testing.

I put a NOS box on my truck a few years ago, when I had both idle problems and backfiring, and all the problems went away, and I could then see on the A/F meter the fuel decel circuit working when I let off the throttle.

You were really lucky to find a NOS box that fixed your problems. I learned about emission systems in the early 70's, when I purchased a 69 Ford F-100. It had to be retrofitted with a spark retard module on the distributor. Talk about effecting drivability! Fortunately I have great smog test/repair shop in the area which has helped keep my 40/60's going. But if you really want a headache, look at the vacuum diagram on a 80's vintage Honda. I recall my daughter's Accord had something like twenty vacuum lines coming into the VSV module. Tracing a vacuum leak was a real joy...

 

[1969FJ]

Seems like all is well, unless, you need the IC's. Is there any way to source these IC,s ?

 

[db3]

Seems like all is well, unless, you need the IC's. Is there any way to source these IC,s ?

Looking at the diagram, the IC's are obviously custom units. In theory, the functionality could be duplicated with standard OpAmp(s) and logic modules on a daughter board. But using a failed/damaged module for replacement parts would be the easiest route. That was my idea when I started purchasing used parts.

 

[1969FJ]

Looking at the diagram, the IC's are obviously custom units. In theory, the functionality could be duplicated with standard OpAmp(s) and logic modules on a daughter board. But using a failed/damaged module for replacement parts would be the easiest route. That was my idea when I started purchasing used parts.

I figured that. IC production has changed , especially proprietary stuff that is hardly used anymore. I suppose if one decoded the exact function, a small programmable mini computer like Arduino could be put in that box.

 

[Engineer8000]

Seems like all is well, unless, you need the IC's. Is there any way to source these IC,s ?

Yes, those ICs show as in stock at a few locations so will be getting some on order.

 

[1969FJ]

Yes, those ICs show as in stock at a few locations so will be getting some on order.

They must not be as proprietary as one would think. Usually the legacy stuff falls out unless there is enough legacy equipment that allows production to continue.

 

[Engineer8000]

They must not be as proprietary as one would think. Usually the legacy stuff falls out unless there is enough legacy equipment that allows production to continue.

They are advertised as surplus so must be left over from the 80s. I cant imagine these had much of a demand, at least in the US after everything went to EFI.

 

[Engineer8000]

Received some parts from the far east. Fully stocked for emissions computers or fan relays.

 

[JuanJ]

I spent some time in the shop reverse engineering this module and drew up the schematics for the different functions. It has two proprietary ICs on it, one that handles RPM and one that handles the speed sensor and temperature sensor. These turn various transistors on and off to perform the required functions based on speed, rpm, OC temperature and vacuum. I was able to determine the signals required to simulate the speed and rpm inputs and the resistance of the OC temperature sensor at its setpoints. This one works, kindly provided by @Spike Strip to get this effort off the ground.



Testing

Hello,

Nice setup. Nice Hewlett-Packard test equipment, too.

Is that an HP-42S?







Juan

 

[Engineer8000]

Yes, that was the first good calculator I bought new when I got out of college. The HP stuff is built like a tank.

 

[1911]

Yes, that was the first good calculator I bought new when I got out of college. The HP stuff is built like a tank.

I still use the HP 11C that I bought new in 1981 or 1982, every day. Still works great. Three of the four rubber feet on the back of it have fallen off.

HP11C

• 1911
• Mar 8, 2018