The 1987 Oldsmobile Delta 88 presents a unique challenge when it comes to diagnosing engine problems. This model year falls into a transitional period between OBD1 and OBD2 systems. While technically still using an OBD1 system, the 1987 Delta 88’s ECM (Engine Control Module) exhibits some OBD2 characteristics, including the occasional use of OBD2 codes. This can lead to confusion when trying to locate the diagnostic port.
Understanding the Hybrid System
The 1987 Delta 88 utilizes a hybrid system, essentially an OBD1 system with some OBD2 features. This means it can sometimes communicate using OBD2 codes, making it compatible with certain OBD1 readers equipped with an OBD2 cable. Inexpensive code readers, like the AutoXray, can often successfully read these codes. However, the diagnostic port location remains consistent with the OBD1 standard.
Locating the OBD1 Diagnostic Port
Unlike later OBD2 systems with a standardized port location, OBD1 ports can vary depending on the manufacturer and model. For the 1987 Oldsmobile Delta 88, the diagnostic port is typically located under the hood, often near the firewall on the driver’s side. It might be a single connector or a series of connectors depending on the specific configuration of the vehicle. Consulting the vehicle’s service manual is recommended for precise location.
Common Issues with the 1987 Delta 88 ECM
The ECMs in these vehicles, particularly those used in full-size GM cars from 1994-1995, were known for their reliability issues. Problems ranged from intermittent no-starts to erroneous coolant over-temperature codes. One peculiar issue involved the ECM requiring a short “warm-up” period after turning the key to the “on” position before starting the engine. This warm-up allowed the chip inside the ECM to function correctly, avoiding certain error codes. These ECM failures often presented in various ways, making diagnosis challenging.
Dealing with ECM Problems
While a failing ECM might be the culprit for various issues, it’s crucial to rule out other potential causes before replacing it. However, due to the known problems with these specific ECMs, keeping a spare might be a wise precaution for owners of 1987 Delta 88s and similar GM vehicles of that era. Replacing the ECM is often a straightforward process, but accurate diagnosis is essential to avoid unnecessary repairs.
