It's my experience that the 85-7 2bbl computers are interchangeable

Click Here to read more about the spark computer and what it does.

Click Here for info on alternative distributor caps

With a different distributor you could bypass the computer completely and tune the spark advance curve to your liking.

Mallory Ignitions has two ECU conversion distributors for the 2.2/2.5

Part Number	Description
2570901	Dual Point w/Mechanical Advance
3770901	Mallory Unilite w/Mech. Advance

The cheapest I've seen the Unilite model was around $300, which I thought was too much considering a V8 distributor has more parts inside it and costs less.

The 1980 Omni/Horizons with the VW 1.7 engines and "federal" emissions package have a distributor similar to the 2.2s with vacuum & centrifugal advance that uses a regular old ECU ignition box. The part numbers for this distributor are 5206935 or 5206925 (not sure what the difference is yet) and the number for the ECU box is 5206390 (the ECU is different then the ones used on V8 models)

The 1.7 distributors won't directly plug into a 2.2 engine because the drive gear is different and the shaft is too long.
To install in a 2.2 you have to remove the drive gears from the 1.7 unit, swap the shaft & advance mechanisms to a 2.2 distributor, cut the shaft down to size and re-install a 2.2 drive gear. Install the distributor -you will have to "re-phase" the intermediate shaft (loosen timing belt and rotate the dist. drive gear) so the vacuum advance can doesn't hit the engine block when installed. Then swap the vacuum line from the stock computer to the vacuum advance on the distrib, and wire in the regular ECU box from the 1.7 engine. The wiring pin-outs appear below. The color codes "should" be the same between the 1.7 & 2.2 wiring harnesses for all model years.

Obviously this by-passes the stock computer so you would lose the feedback carburetion system, along with the radiator fan control and tachometer in the dash..
To get the tach working again you can splice the grey w/blue striped wire at the middle of the 14pin computer connector ('85-87) to the black w/yellow stripe wire at the ECU. Splice and adjustable thermostat into the fan relay wiring or simply ground the relays trigger wire and the fan will run all the time.

I have done this to my car and it does not add a whole lot of power, just a little bit in the low to mid RPM range. A local machine shop cut and re-geared the distributor for less then $20. The idle quality is the same, but the timing mark stays in the same place when you shine the timing light on it and does not bounce around at all.
The base timing on my car is set at 12 with the ECU ignition (previously set at 15 with stock computer. I plan on increasing the base timing back to 15 and tuning the centrifugal advance (changing the springs) in the near future which should yeild better accelleration.

The early 1.9 Ford Escorts and some VWs have an interesting camshaft mounted distributor that shows promise for use on other vehicles...

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