Did you receive the email I sent with some phone numbers? Crankshaft or camshaft sensor picks up a signal from a point on either and sends a signal to the ECM. This controls the firing of the injectors, and spark. It tells the ECM a lot about what the engine's doing, like speed, and mixes this info with other sensor info to determine spark advance, etc. I've looked through the manual and the only reference I can find for crankshaft position sensing is in the Electronic Spark Timing section. It says the ECM receives a reference pulse from the DISTRIBUTOR which indicates both engine rpm and crankshaft position. Of course, the 88 4-cylinder didn't have a distributor. I can't even find reference in the index. I'll search further.
As a check to see if it has a crankshaft or camshaft sensor, call Main Auto Parts on West Pike Street in Lawrenceville. Ask for Bill or Keith, and see if they have one listed. If not, then it doesn't have one.