Engine misfire?

Hi chrisletua,

Did the Malfunction Indicator Light show? Did you test the fuel pressure? This guide can help us fix it

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please run down this guide and report back.

Hi chrisletua,

Pull a plug wire out and attach a spark plug. Crank and watch the color of the spark, should be builsh.

Hi chrisletua,

Should be NGK BKR6E-11. I need to know the engine variant to be sure.

Hi chrisletua,

We would always have our arms opened to welcome you anytime.

NGK BKR6E would have a gap of 0.8 mm whereas the 11 = 1.1 mm. You can use the plug but they have to be regapped.

A smaller gap would cause higher fuel consumption.

Where the gas consumption is concerned, it would be hard to advise or suggest anything.

Possible causes.
1. Engine ignition timing.
2. Idle speed adjustment.
3. Driving method.
4. Brakes.
5, Clutches, might be worn and slipping causing power losses too.

Hi Christopher,

When a plug keeps shorting out, you need to check if the compression is good.

Another problem could be oil leaking into the cylinders causing the plugs to foul up. Might be due to worn valve stem seals, which is quite likely based on the year of your vehicle. Is the engine oil consumption high after the long distance drive?

3rd thing to check would be the spark plug cables which I seem to have missed out the last time. Get an ohmmeter to test the ohms, should have continuity but below 25 k ohms. Do you have hesitation while accelerating?

MERRY CHRISTMAS

Hi Christopher,

If you do not have excessive engine oil consumption or overheating problem the engine is still going strong. Not necessary to replace it.

Unless the compression is low, then you might need to rebuild or replace it.

Btw you should check if the catalytic converter is clogged. It would affect performance and would cause plugs to short, but mostly the plugs would wear of the electrodes.

If you have sooty sparks, either the spark is weak, which can be due to a bad plug wire, or faulty injector, causing flooding, ie excessive fuel getting to the cylinder.

Hi Christopher,

Some teting would need to be done to find out what is wrong and I need tounderstand the situation better.

If the ECU is equipped with 4 LED then this should be a 86 model and not 89 as stated.

It uses the binary system for counting the codes, with 8, 4, 2, 1 respectively. I do not understand what you meant by D1 to D4 so hope my explanaion of the LED would enable you to read the codes better. 1 starts from right and is read leftwards.

Maybe you should test the coolant temperature sensor and or it circuit. Your problem seems likely to be caused by it.

The D1 to D4 are the circuit board schematic diodes.

I have the testing diagnostic for the various circuits but it is not the correct position as the ECU connectors unless you have the Diagnostic Harness Checker. Refer to lower diagram for wire colors. You can back probe the connectors by removing the ECU from its mounting points.
A = biggest connector ( white) you need to backprobe the C connector.

Note the wire colors at ECT, you have the correct pix of it.

SELF-DIAGNOSTIC LIGHTS NO. 1 & 4 ON OR LIGHT BLINKS 5 TIMES
NOTE: Check control box vacuum hose routing before proceeding with trouble shooting.

1. Ensure MAP sensor vacuum hoses are properly connected. Disconnect vacuum hose from MAP sensor and plug open end of hose. Disconnect vacuum hose No. 21 from throttle body (vacuum hose between MAP sensor and throttle body on CRX Si). Connect vacuum pump to hose and apply vacuum.

2. If vacuum does not hold, replace hose. If vacuum remains constant, plug system checker harness between control unit and connector. Connect positive voltmeter probe to terminal C15 (Red/White wire) and negative probe to terminal C14 (Blue/White wire). Turn ignition on and check voltage.
3. Voltage should be 4.75-5.25 volts. If voltage is not within specification, replace ECU and retest. If voltage is within specification, connect voltmeter positive probe to terminal C11 (White/Blue wire) and negative probe to terminal C14 (Blue/White wire).
4. Voltage should be 2.76-2.96 volts. If voltage is not within specification, check and repair open/short circuit in Blue/White or White/Blue wires (White/Red or Brown/White wires on CRX Si) between MAP sensor and ECU. Check for faulty MAP sensor.
5. If voltage is within specification, connect vacuum pump to MAP sensor. Ensure voltage varies as vacuum is applied. If voltage does not vary, replace MAP sensor. If voltage varies, replace ECU and retest.

SELF-DIAGNOSTIC LIGHTS NO. 2 & 8 ON OR LIGHT BLINKS 10 TIMES
1. Plug system checker harness between ECU and connector. Connect voltmeter positive probe to terminal C5 (White/Red wire) and negative probe to terminal C12 (Green/White wire). Turn ignition on. Ensure voltage reading is correct for intake air temperature.
2. If voltage is correct, replace ECU and retest. If voltage is not correct, turn ignition off. Check for open/short circuit in White/Red and Green/White wires (Red/Yellow and Brown/Black wires on CRX Si) between intake air temperature sensor and ECU. Repair wiring if necessary. If wiring checks okay, check intake air temperature sensor. Replace sensor if defective. If sensor tests okay, replace ECU and retest.

Hi omilee3233,

When CEL is showing, you need retrieve the Diagnosti Trouble Code to find out what is wrong first.

Depending on the type of ECM, some might have the LED on the ECM. Just tuen ignition switch on anc cout the numner of flashes to determine the DTC. Get the code and post here for further diagnosis.