88 Corsica runs rough and suspect the timing is out Where does one do for Used to doing coarse adjustments from distributor but see it Wires disappear behind engine?

The distributor on a 1988 Corsica is notoriously difficult to access, with the wiring often disappearing into the engine bay's recesses. Coarse timing adjustments on this model are not done by simply turning the distributor. You should never attempt to adjust the ignition timing using just the distributor without proper tools and understanding. Incorrect timing can seriously damage the engine.

Here's what you should do:

1. Safety First: Disconnect the negative battery terminal before starting any work on the ignition system.

2. Identify the problem: Rough running can have many causes besides timing. Check for other potential issues *before* assuming it's the timing:

* Spark Plugs & Wires: Inspect for cracks, corrosion, or damage. Replace as needed. Worn spark plugs can easily mimic timing problems.

* Ignition Coil: A failing ignition coil can cause misfires.

* Fuel System: Check fuel pressure, fuel filter, and air filter. A dirty or clogged fuel system can lead to rough running.

* Sensors: Various sensors (e.g., crankshaft position sensor, oxygen sensor) can affect engine performance. A faulty sensor can trick the computer into incorrect timing.

* Vacuum Leaks: Inspect all vacuum hoses for cracks or leaks.

3. Locate the Timing Mark: Once you've ruled out other issues, find the timing mark on the crankshaft pulley (often a notch or pointer). You'll also need to find the timing mark on the distributor. Accessing them might require removing some components to get a clear view. A shop manual will be very helpful here.

4. Use a Timing Light: You'll need a timing light to accurately set the ignition timing. This tool flashes in sync with the engine's spark, allowing you to see the crankshaft timing mark's position relative to the pointer on the timing cover.

5. Consult a Repair Manual: A Haynes or Chilton repair manual specific to your 1988 Chevrolet Corsica is essential. These manuals provide detailed instructions, diagrams, and specifications for setting the ignition timing correctly. They'll show you how to access the timing marks and the correct procedure.

6. Consider Professional Help: If you're not comfortable working on your car's ignition system, it's best to take it to a qualified mechanic. Incorrect timing adjustments can lead to serious engine damage. The difficulty of access on the Corsica makes this a challenging DIY task.

In short: While you *could* theoretically adjust the distributor, it's extremely unwise without a timing light and the knowledge of where to find the timing marks. Focusing on easier-to-check components first is a more efficient approach. The best way to address the timing is through the use of a timing light and a shop manual.