QuestionI have a 1988 GMC 1500 High Sierra running very rough, idles rough, service engine light comes on and it will almost die unless I punch on the gas pedal. what can i check?
Answer1 Inspect Air Filter Restricted or clogged air filter.
2 Inspect Fuel Filter Clogged or dirty fuel filter
3 Inspect Wireset Damaged, worn, or deteriorating spark plug or coil wire(s).
4 Inspect Spark Plug Fouled, damaged or broken spark plug(s).
5 Inspect PCV Valve Plugged or damaged pcv valve.
6 Inspect Distributor Cap Loose or cracked distributor cap
7 Inspect Carburetor Float Improperly adjusted/saturated or damaged carburetor float.
8 Inspect Choke Pulloff Worn, defective, or faulty choke pulloff(s).
9 Inspect Choke Thermostat Stuck or improperly functioning choke thermostat.
10 Inspect Hood Brace Leaking, worn, or damaged intake manifold gasket
11 Inspect Air Charge Sensor Damaged or faulty air charge sensor or air charge sensor circuit.
12 Inspect Air Cleaner Temperature Sensor Damaged or faulty air cleaner temperature sensor or air cleaner temperature sensor circuit.
13 Inspect Barometric Pressure Sensor Damaged or faulty barometric pressure sensor or barometric pressure sensor circuit.
14 Inspect Fuel Injector Cold Start Valve Faulty cold start valve or circuit.
15 Inspect Fuel Injector Pressure Regulator Faulty fuel injector pressure regulator or circuit.
16 Inspect Carburetor/Fuel Injection Gsk Deteriorated, or faulty carburetor/throttle valve mounting gasket.
19 Inspect Idle Air Control Valve Damaged, loose, or faulty idle air control valve.
20 Inspect Idle Speed Control Actuator Damaged, loose, or faulty idle speed actuator.
21 Inspect MAP Sensor Improperly connected or faulty m.a.p. sensor.
22 Inspect Mass Air Flow Sensor Improperly connected or faulty mass air flow sensor.
23 Inspect Throttle Position Sensor Faulty throttle position sensor or throttle position sensor circuit.
24 Inspect Timing Set Slipped timing chain or worn timing gear(s).
25 Inspect Spark Plug Wire Loom - Performance Improperly adjusted or worn/malfunctioning carburetor.
26 Inspect Fuel Pump Improperly functioning fuel pump or circuits.
27 Inspect Fuel Tank Contaminated fuel from rusted or deteriorated fuel tank.
28 Inspect Fuel Injector Plugged, dirty or poorly connected fuel injector.
29 Inspect EGR Valve Clogged, dirty or improperly functioning or defective egr valve.
30 Inspect Distributor Worn, loose or incorrectly adjusted distributor.
31 Inspect Camshaft Worn or scored camshaft lobes may affect proper fuel intake, compression, combustion and exhaust.
Good Luck
Bruce
