Fuel injection and EGR problems

PRO2COM

MEMBER
1987 HONDA ACCORD
165,000 MILES

This car has error code of 12 = egr system problem. The valve moves freely and when testing switch it goes from.75 - 1.6 ohms. Is that normal? The car will warm up normal and then will loose power it acts like a miss and you can not run above 1500 rpm with out stalling. I tried starter fluid and it runs normal as long as I kept spraying. The fuel pump hold 33 - 35 with the regulator and 38 - 40 with out the regulator in use.

1 Reply

KHLOW2008

MECHANIC
41,814 POSTS

The fuel pressure readings are within specifications.

I would suggest checking the EGR system first.

CODE 12, EGR SYSTEM

1. Check harness and connections between EGR valve and ECU. Warm engine to normal operating temperature (cooling fan on). Disconnect vacuum hose from EGR valve. Using a hand-held vacuum pump, apply vacuum to EGR valve. If vacuum does not hold, and engine does not stall, replace faulty EGR valve or clean blocked EGR passages.

2. If vacuum held and engine stalled in step 1), restart engine. Open control box. Verify vacuum from intake manifold to CVC valve. Repair as necessary. Reconnect manifold vacuum hose. Disconnect vacuum hose between CVC valve and air chamber. Connect vacuum gauge and check for about 8 in. Hg.

3. If reading is not about 8 in. Hg, replace CVC valve. If vacuum is correct, reconnect vacuum hose. Install vacuum gauge at EGR valve hose. Disconnect electrical connector from control box. Jumper voltage to Black/Yellow wire terminal of box and ground to Red wire terminal of box. Reading at EGR valve hose should now be
about 8 in. Hg.

4. If vacuum reading is not correct, replace EGR control solenoid. If reading is correct, measure voltage from ground to Black/Yellow wire of control box harness connector. If battery voltage is not present, repair open in Black/Yellow wire between No. 1 fuse and control box harness connector.

5. If battery voltage is present, turn ignition off. Connect test harness between EGR lift sensor and sensor harness connector. Turn ignition on. Measure voltage between Red (pos.) And Green (neg.) Terminals. If voltage is about 5 volts, go to step 7). If voltage is not about 5 volts, measure voltage between ground and Red terminal. If voltage is now about 5 volts, repair open in Green/White wire between ECU terminal C12 and sensor.

6. If voltage is not about 5 volts, turn ignition off. Connect system checker harness between ECU and ECU connector. Measure voltage between terminals C13 (pos.) And C12 (neg.). If voltage is now about 5 volts, repair open in Yellow/White wire between ECU terminal C13 and sensor. If voltage is not about 5 volts, substitute a known good ECU. If condition is rectified, replace original ECU.

7. Measure voltage between White (pos.) And Green (neg.) Terminals. If voltage reading is not about one volt, replace EGR valve or repair short in Red wire between ECU terminal A10 and EGR control solenoid. If about one volt is measured, turn ignition off. Connect system checker harness between ECU and ECU connector.

8. Turn ignition on. Measure voltage between terminals C8 (pos.) And C12 (eng.). If voltage is not about one volt, repair open in Yellow wire between ECU terminal C8 and sensor. If voltage is about one volt, disconnect "A" connector from ECU only, not from main harness.

9. Measure voltage between terminals A10 (pos.) And A18 (neg.). If battery voltage is not present, repair open or short in Red wire between ECU terminal A10 and EGR control solenoid. If battery voltage is present, substitute a known good ECU. If condition is rectified, replace original ECU.