Compression
| WARNING | DO NOT use ignition switch during compression tests on fuel injected vehicles. Use a remote starter to crank engine. Fuel injectors on many models are triggered by ignition switch during cranking mode, which can create a fire hazard or contaminate engine oiling system. |
Note. Before checking engine compression pressure ensure engine oil level is correct. Ensure starter motor and battery are operating properly.
Check engine mechanical condition using a compression gauge, vacuum gauge or engine analyzer. See engine analyzer manual for specific instructions. Start engine and allow it to operate until coolant temperature is 176-205°F (80-96°C). Check engine compression with engine at specified cranking speed, all spark plugs removed and throttle wide open. For engine compression specifications, see COMPRESSION SPECIFICATIONS table.
| Application | (1) Specification | ||
|---|---|---|---|
| Compression Pressure | |||
| Accent | |||
| Standard Value | 218 psi (15.3 kg/cm 2 ) | ||
| Limit Value | 203 psi (14.3 kg/cm 2 ) | ||
| Elantra | |||
| Standard Value | 218 psi (15.3 kg/cm 2 ) | ||
| Limit Value | 203 psi (14.3 kg/cm 2 ) | ||
| Santa Fe | |||
| Standard Value | 170 psi (12.0 kg/cm 2 ) | ||
| Limit Value | 150 psi (11.0 kg/cm 2 ) | ||
| Sonata | |||
| Standard Value | 170 psi (12.0 kg/cm 2 ) | ||
| Limit Value | 150 psi (11.0 kg/cm 2 ) | ||
| Tiburon (2.0L) | |||
| Standard Value | 218 psi (15.3 kg/cm 2 ) | ||
| Limit Value | 203 psi (14.3 kg/cm 2 ) | ||
| Tiburon (2.7L) | |||
| Standard Value | 170 psi (12.0 kg/cm 2 ) | ||
| Limit Value | 150 psi (11.0 kg/cm 2 ) | ||
| XG350 | |||
| Standard Value | 170 psi (12.0 kg/cm 2 ) | ||
| Limit Value | 150 psi (11.0 kg/cm 2 ) | ||
| Maximum Variation Between Cylinders | |||
| All Models | 14 psi (1.0 kg/cm 2 ) | ||
| (1) Checked with engine coolant temperature at 176-205°F (80-96°C) and engine speed at 250-400 RPM. | |||
| (1) | Checked with engine coolant temperature at 176-205°F (80-96°C) and engine speed at 250-400 RPM. |
COMPRESSION SPECIFICATIONS
Exhaust System Backpressure
Exhaust system backpressure can be checked with a vacuum or pressure gauge. If using a pressure gauge, remove front heated oxygen sensor. Connect a 1.0-5.0 psi (.07-.35 kg/cm 2 ) pressure gauge and run engine at 2500 RPM. If exhaust system backpressure is greater than 2.0 psi (.14 kg/cm 2 ), exhaust system or catalytic converter is plugged.
If using a vacuum gauge, connect vacuum gauge hose to intake manifold vacuum port and start engine. Observe vacuum gauge. Open throttle part way and hold steady. If vacuum gauge reading slowly drops after stabilizing, check exhaust system for restrictions.
FUEL SYSTEM
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. See FUEL PRESSURE RELEASE . DO NOT allow fuel to contact engine or electrical components. |
| WARNING | After repairs have been completed, using fuel pump check connector terminal, activate fuel pump and check for leaks. Repair any leaks as necessary. |
| CAUTION | When battery is disconnected, vehicle computer and memory system may lose memory data. Driveability problems may exist until computer system have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION before disconnecting battery. |
Note. If fuel pressure is not as specified, perform fuel filter inspection. For fuel filter location, removal and installation, see FUEL FILTER under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. If fuel filter checks okay, check fuel pump. See FUEL PUMP TEST .
Except Accent & Santa Fe
Locate and remove fuel pump access panel in trunk. Disconnect fuel pump harness connector. Start engine and allow it to idle. After engine stalls, turn ignition off. Disconnect negative battery cable reconnect fuel pump harness connector. When repairs are completed and fuel lines are properly secured reconnect negative battery cable. Locate fuel pump check connector under left side of dash. Apply battery voltage at check connector terminal No. 9 to activate fuel pump. (Scheme 17) Check for leaks, repair as necessary.
Scheme 17
Accent
Locate and remove fuel pump access panel under rear seat. Disconnect fuel pump harness connector. Start engine and allow it to idle. After engine stalls, turn ignition off. Disconnect negative battery cable and reconnect fuel pump harness connector. When repairs are completed and fuel lines are properly secured, reconnect negative battery cable. Locate fuel pump check connector in engine compartment fuse/relay box. (Scheme 18) Apply battery voltage at check connector to activate fuel pump. Check for leaks, repair as necessary.
Scheme 18
Santa Fe
Raise vehicle. Disconnect fuel pump harness connector. Start engine and allow it to idle. After engine stalls, turn ignition off. Lower vehicle. Remove fuel tank filler cap. Disconnect negative battery cable reconnect fuel pump harness connector. When repairs are completed and fuel lines are properly secured reconnect negative battery cable. Locate fuel pump check connector under left side of dash. Apply battery voltage at check connector terminal No. 9 to activate fuel pump. (Scheme 17) Check for leaks, repair as necessary.
Fuel Pressure (Accent)
Note. Fuel pressure regulator is an integral part of fuel pump and is not serviced separately.
Scheme 19
- Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-152016-S27651135502003011300000). Disconnect negative battery terminal, reconnect fuel pump harness connector and go to next step.
- Disconnect high-pressure fuel hose from fuel delivery pipe. Cover hose connection using rags to avoid spraying of fuel, and go to next step.
- Using Fuel Pressure Gauge Adapter (09353-38000) and fuel pressure gauge connector (09353-24000), install fuel pressure gauge (09353-24100) to fuel delivery pipe. (Scheme 19) Tighten fuel gauge adapter bolts to 18-26 ft. lbs. (24.4-35.3 N.m). Connect negative battery cable.
- Locate fuel pump check connector, see «FUEL PUMP CHECK CONNECTOR LOCATOR»(ref-152016-S19806883282003011300000) table. Apply battery voltage at check connector to activate fuel pump. (Scheme 18) Ensure no fuel leakage is present at pressure gauge or connection. If no leaks are present, start engine and allow it to idle, go to next step.
- Measure and record fuel pressure at idle. See «REGULATED FUEL PRESSURE (AT IDLE)»(ref-152016-S09592029012003011300000) table. If fuel pressure is as specified, go to step 8. If fuel pressure is less than specified, go to next step. If fuel pressure is greater than specified, go to step 7. REGULATED FUEL PRESSURE (AT IDLE) Application At Idle W/Vacuum psi (kg/cm 2 ) At Idle W/O Vacuum psi (kg/cm 2 ) Accent 50 (3.52) (1) Elantra 50 (3.52) (1) Santa Fe 38 (2.67) 46-49 (3.23-3.45) Sonata 38 (2.67) 47-50 (3.31-3.52) Tiburon 2.0L 50 (3.52) (1) 2.7L 38 (2.67) 47-50 (3.31-3.52) XG350 37 (2.57) 46-49 (3.26-3.47) (1) Fuel pressure regulator is an integral part of the fuel pump assembly.
- Check for restricted fuel filter. Check for fuel leak on return side, caused by poor seating of fuel pressure regulator. Replace fuel filter or fuel pump assembly as necessary. After repair, go to step 8.
- Check for sticking fuel pressure regulator. Check for restricted or bent fuel return hose or pipe. Repair or replace fuel hose, pipe or fuel pump assembly as necessary. After repair, go to next step.
- Stop engine and check gauge for decrease in fuel pressure. Fuel pressure should hold for approximately 5 minutes. If fuel pressure holds as specified, go to step 10. If fuel pressure does not hold as specified, go to next step.
- If fuel pressure decreases slowly after engine is stopped, check for leaking injector. If fuel pressure decreases immediately after engine is stopped, fuel pump check valve is not working. Replace fuel injector or fuel pump as necessary. After repairs, recheck fuel pressure and go to next step.
- After testing is completed, release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-152016-S27651135502003011300000). Disconnect fuel pressure gauge from adapter. Ensure hose connection is covered by shop towel to prevent fuel spray. Remove adapter bolts and adapter, install NEW "O" ring, reinstall fuel line with original bolts and tighten bolts to 18-26 ft. lbs. (24.4-35.3 N.m). Apply battery voltage to fuel pump check connector terminal. (Scheme 18) Recheck for fuel leaks.
Fuel Pressure (Elantra & Tiburon)
- Release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-152016-S27651135502003011300000). Disconnect negative battery terminal and reconnect fuel pump harness connector.
- Disconnect high-pressure fuel hose from fuel delivery pipe. Cover hose connection using rags to avoid fuel spray.
- Using Fuel Pressure Gauge Adapter (09353-38000) and fuel pressure gauge connector (09353-24000), install fuel pressure gauge (09353-24100) to fuel delivery pipe. (Scheme 19) Tighten fuel gauge adapter bolts to 18-26 ft. lbs. (24.4-35.3 N.m). Connect negative battery cable.
- Locate fuel pump check connector, see «FUEL PUMP CHECK CONNECTOR LOCATOR»(ref-152016-S19806883282003011300000) table. Apply battery voltage at fuel pump check connector terminal No. 9 to activate fuel pump. (Scheme 17) Ensure no fuel leakage is present at pressure gauge or connection. If no leaks are present, start engine and allow it to idle. Go to next step.
- Disconnect vacuum hose from fuel pressure regulator, and plug hose end. Measure and record fuel pressure at idle. Reconnect vacuum hose, and again measure and record fuel pressure. See «REGULATED FUEL PRESSURE (AT IDLE)»(ref-152016-S09592029012003011300000) table. If fuel pressures are as specified, go to step 9. If fuel pressures are less than specified, go to next step. If fuel pressures are greater than specified, go to step 7. If fuel pressure does not change when regulator vacuum hose is connected and disconnected, go to step 8.
- Check for following conditions: Restricted fuel filter. Fuel pressure regulator leaking fuel to fuel return side. Leaking in-tank fuel pick-up hose. Low fuel pump discharge pressure. Repair or replace as necessary, and recheck fuel pressure. After repair, go to step 10.
- Check for sticking fuel pressure regulator, restricted or bent fuel return hose or pipe. Repair or replace fuel hoses or pipe, or replace fuel pressure regulator.
- Check for following conditions: Restricted or damaged vacuum hose. Restricted manifold vacuum port. Sticking or poorly seated fuel pressure regulator valve. Repair or replace as necessary, and recheck fuel pressure. After repair, go to step 10.
- If fuel pressures are as specified, stop engine and check for decrease in fuel pressure gauge. Fuel pressure should hold for approximately 5 minutes. If fuel pressure decreases slowly after engine is stopped, check for leaking injector. Replace as necessary. If fuel pressure decreases immediately after engine is stopped, fuel pump check valve is not working. Replace fuel pump. After repairs are completed, recheck fuel pressure and go to next step.
- After testing is completed, release fuel pressure. See «FUEL PRESSURE RELEASE»(ref-152016-S27651135502003011300000). Disconnect fuel pressure gauge from adapter. Ensure hose connection is covered by shop towel to prevent fuel spray. Remove adapter bolts and adapter. Install NEW "O" ring and reinstall fuel line with original bolts and tighten fuel hose bolts to 18-26 ft. lbs. (24.4-35.3 N.m). Apply battery voltage to fuel pump check connector terminal No. 9. (Scheme 17) Check for fuel leaks.
ENGINE CONTROL RELAY
| CAUTION | When applying direct battery voltage, ensure voltage is applied to correct terminal to prevent damage to relay or circuits. To identify circuits and circuit wire color, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. |
Note. Engine control relay may also be referred to as ECM control relay or MFI control relay.
FUEL PUMP RELAY
| CAUTION | When applying direct battery voltage, ensure voltage is applied to correct terminal to prevent relay or circuits damage. To identify circuits and circuit wire color, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. |
IGNITION CHECKS
Note. When troubleshooting components and component control circuits, see appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
All model are equipped with a Distributorless Ignition System (DIS). DIS is a molded, dual-coil system. Ignition timing is controlled by the electronic control ignition timing system. The ignition timing curves for the engine operating conditions are programmed into the Engine Control Module (ECM) memory.
SPARK (SPARK PLUG & CABLE)
Connect spark plug to a high tension cable. Ensure spark plug gap is 0.039-0.043" (1.0-1.1 mm). Ground outer spark plug electrode (main body of spark plug), and crank engine. Spark should occur in discharge gap between electrodes. Also check spark plug wire resistance on suspect wires. See HIGH-TENSION WIRE RESISTANCE table.
| Wire Application | (1) Ohms | ||
|---|---|---|---|
| Accent | |||
| BOUGI | |||
| No. 1 (22" - 560 mm) | 2.51-3.76 | ||
| No. 2 (17" - 440 mm) | 1.97-2.96 | ||
| No. 3 (14" - 360 mm) | 1.61-2.42 | ||
| No. 4 (12" - 310 mm) | 1.39-2.08 | ||
| R16AIPS | |||
| No. 1 (22" - 560 mm) | 5.60-11.76 | ||
| No. 2 (17" - 440 mm) | 4.40-9.24 | ||
| No. 3 (14" - 360 mm) | 3.60-7.56 | ||
| No. 4 (12" - 310 mm) | 3.10-6.51 | ||
| Elantra | |||
| BOUGI | |||
| No. 1 (24" - 605 mm) | 2.71-4.07 | ||
| No. 2 (21" - 545 mm) | 2.44-3.66 | ||
| No. 3 (18" - 450 mm) | 2.02-3.02 | ||
| No. 4 (15" - 370 mm) | 1.66-2.49 | ||
| R16AIPS | |||
| No. 1 (24" - 605 mm) | 6.05-12.71 | ||
| No. 2 (21" - 545 mm) | 5.45-11.45 | ||
| No. 3 (18" - 450 mm) | 4.50-9.45 | ||
| No. 4 (15" - 370 mm) | 3.70-7.77 | ||
| Santa Fe | |||
| 2.4L | (2) (3) | ||
| 2.7L | |||
| No. 1 | 4.39-6.59 | ||
| No. 2 | 2.28-3.43 | ||
| No. 3 | 3.49-5.24 | ||
| No. 4 | 1.90-2.86 | ||
| No. 5 | 3.25-4.87 | ||
| No. 6 | 1.30-1.95 | ||
| 3.5L | (3) | ||
| Sonata | |||
| 2.4L | (2) (3) | ||
| 2.7L | |||
| No. 1 | 4.39-6.59 | ||
| No. 2 | 2.28-3.43 | ||
| No. 3 | 3.49-5.24 | ||
| No. 4 | 1.90-2.86 | ||
| No. 5 | 3.25-4.87 | ||
| No. 6 | 1.30-1.95 | ||
| Tiburon | |||
| 2.0L | (3) | ||
| 2.7L | |||
| No. 1 | 4.39-6.59 | ||
| No. 2 | 2.28-3.43 | ||
| No. 3 | 3.49-5.24 | ||
| No. 4 | 1.90-2.86 | ||
| No. 5 | 3.25-4.87 | ||
| No. 6 | 1.30-1.95 | ||
| XG350 | (3) | ||
| (1) Resistance should not be more than 10,000 ohms per foot of spark plug cable. (2) 2.4L engine uses 2 ignition coils with an internal power transistor. Ignition coil No. 1 is located on cylinder No. 1 spark plug. Ignition coil No. 2 is located on cylinder No. 2 spark plug. (3) Information is not available from manufacturer. | |||
| (1) | Resistance should not be more than 10,000 ohms per foot of spark plug cable. |
| (2) | 2.4L engine uses 2 ignition coils with an internal power transistor. Ignition coil No. 1 is located on cylinder No. 1 spark plug. Ignition coil No. 2 is located on cylinder No. 2 spark plug. |
| (3) | Information is not available from manufacturer. |
HIGH-TENSION WIRE RESISTANCE
CAMSHAFT POSITION SENSOR
See related DTC in appropriate SELF-DIAGNOSTICS article.
CRANKSHAFT POSITION SENSOR
See related DTC in appropriate SELF-DIAGNOSTICS article.
IDLE SPEED & IGNITION TIMING
Note. Idle speed and ignition timing is controlled by computer and is not adjustable. Specifications are for inspection only.
Base Idle Speed
Note. Before checking engine idle speed, ensure spark plugs, injectors, and Idle Speed Control (ISC) actuator are operating properly. Check engine mechanical condition and ensure compression is within specification. Idle speed is controlled by ISC actuator and is not adjustable.
- Ensure coolant temperature is 176-205°F (80-95°C). Turn lights and all accessories off. DO NOT check base idle speed while cooling fan is operating. Set transaxle in Park or Neutral (A/T) or Neutral (M/T). On vehicles equipped with power steering, ensure front wheels are pointed straight-ahead. Connect a tachometer to the primary coil side or a Hi-Scan Pro tool or equivalent to Data Link Connector (DLC). Located at lower crash pad, below steering column. (Scheme 20)
- Start engine and allow it to idle. Increase engine speed to 2000-3000 RPM for at least 5 seconds and then allow engine to idle. Check and ensure timing is as specified. See «IGNITION TIMING SPECIFICATIONS»(ref-152016-S41992737012003011300000) table.
- Operate engine at idle for at least 2 minutes before checking idle speed. See «BASE IDLE SPEED SPECIFICATIONS»(ref-152016-S34320199132003011300000) table. If idle speed is not within specification, check for Diagnostic Trouble Codes (DTCs). If there are DTCs present, see appropriate DTC testing procedure under DIAGNOSTIC TEST in appropriate SELF-DIAGNOSTICS article. If no codes are present, go to «TROUBLE SHOOTING - NO CODES»(ref-152031) article.
| Application | (1) RPM | |
|---|---|---|
| Accent | 650-850 | |
| Elantra | 600-800 | |
| Santa Fe | ||
| 2.4L | 700-900 | |
| 2.7L | 600-800 | |
| 3.5L | (2) | |
| Sonata | ||
| 2.4L | 600-800 | |
| 2.7L | 750-950 | |
| Tiburon | ||
| 2.0L | 600-800 | |
| 2.7L | 650-750 | |
| XG350 | 600-800 | |
| (1) Check idle speed with engine warmed up, lights and accessories off, transmission in Park or Neutral, and steering wheel straight ahead. (2) For information on Santa Fe with 3.5L, refer to FUEL SYSTEM (3.5L) article. | ||
| (1) | Check idle speed with engine warmed up, lights and accessories off, transmission in Park or Neutral, and steering wheel straight ahead. |
| (2) | For information on Santa Fe with 3.5L, refer to FUEL SYSTEM (3.5L) article. |
BASE IDLE SPEED SPECIFICATIONS
Scheme 20
Idle Mixture
Note. Mixture adjustment is computer-controlled and is not adjustable.
IGNITION TIMING
Ignition timing is computer controlled and is not adjustable. Standard reference timing data for various engine operating conditions is stored in Engine Control Module (ECM) memory. ECM controls ignition timing based on engine operating conditions (speed, load, temperature, etc.) and data stored in ECM memory. ECM controls timing through ignition coil operation. When inspecting ignition timing, ensure it is as specified. See IGNITION TIMING SPECIFICATIONS table.
| Application | (1) Base Timing | |
|---|---|---|
| Accent | 4°-14° @ 650-850 RPM | |
| Elantra | 3°-13° @ 600-800 RPM | |
| Santa Fe | ||
| 2.4L | 2°-12° @ 650-850 RPM | |
| 2.7L | 7°-17° @ 600-800 RPM | |
| 3.5L | (2) | |
| Sonata | ||
| 2.4L | 2°-12° @ 600-800 RPM | |
| 2.7L | 7°-17° @ 750-950 RPM | |
| Tiburon | ||
| 2.0L | 4°-14° @ 600-800 RPM | |
| 2.7L | 7°-17° @ 650-750 RPM | |
| XG350 | 3°-7° @ 600-800 RPM | |
| (1) Ignition timing is controlled by computer and is not adjustable. Specification is for inspection only. (2) For information on Santa Fe with 3.5L, refer to FUEL SYSTEM (3.5L) article. | ||
| (1) | Ignition timing is controlled by computer and is not adjustable. Specification is for inspection only. |
| (2) | For information on Santa Fe with 3.5L, refer to FUEL SYSTEM (3.5L) article. |
IGNITION TIMING SPECIFICATIONS
SUMMARY
If no faults were found while performing BASIC DIAGNOSTIC PROCEDURES, proceed to appropriate SELF-DIAGNOSTICS article. If no hard codes are found in self-diagnostics, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., ROUGH IDLE, NO START, etc.) or intermittent diagnostic procedures.