Chevy trucks for the 1988 model year were manufactured with several different engine sizes. They were produced before computer diagnostics; troubleshooting must be conducted without a diagnostic scanner. The trucks do not have high tech sensors and the basic parts of concern are the gaskets, motor, transmission, battery, alternator and starter. Basic troubleshooting is achieved by monitoring the vehicle for new sounds, new feelings and specific function loss during a breakdown. The process of elimination is often the most effective method for pinpointing the mechanical issue.
Drive the truck at variable speeds to test the clutch and transmission. If the truck has an automatic transmission, only test the transmission. Accelerate and decelerate rapidly and listen for grinding when the vehicle shifts. Also pay attention to the timing of the shifting. The transmission must be serviced if it shifts intermittently or does not shift at high engine speeds.
Replace the fuel pump if the vehicle sputters while driving. Eventually the pump will stop feeding gasoline to the fuel injectors and the engine will stop functioning. If the fuel pump is functioning properly, the injectors may require cleaning and replacement.
Jump start the engine with cables and a running vehicle if the truck does not have power. If the battery drains repeatedly, it must be replaced. If a new battery drains repeatedly, the alternator must be replaced.
If the battery and alternator are functioning properly, but the engine will not crank, replace the starter. Slide under the engine and locate the cylinder-shaped starter and hit it with a hammer as a temporary solution.
Turn the truck on sharp corners and listen for squealing. If the vehicle squeals, use a crescent wrench to tighten the belts. If it is difficult to turn the truck on sharp corners, stop the vehicle and shift in and out of four-wheel drive several times. Test again to ensure the transfer case is not locked in four-wheel drive. Difficulty turning also indicates potential power steering failure on both two- and four-wheel drive trucks.
