I'm battling an ongoing Code 4, and can't get it solved. Tried a different used distributor, then a remanufactured distributor to no avail. I changed the ecu, due to a problem with the system not "priming" for a while on first start of the morning, and that didn't solve the CKP sensor issue. I checked continuity from the distributor to the wiring harness connector by the battery, and it was all good. When the issue first presented, the check engine light would not come on for the first 2-10 minutes of driving, then it would come on, the engine would lose power and rev limit to 3,500, and idle at around 1,200. It is now constantly presenting the check engine light with code 4 and giving the previously mentioned symptoms.

Any ideas on the cause?

Are the wire colors to the ecu the same as on the engine side of the firewall, so I can check continuity to the ecu?

 

Left Tower
C101	Tower Harness	4 pin Grey
C102	Tower Harness	10 pin Grey
C103	Tower Harness	14 pin Grey
C129 (VX)	Tower Harness	6 pin Grey
Right Tower
C124	Tower Harness	2 pin Grey	(Power)
C125	Tower Harness	8 pin Grey	Junction
C126	Tower Harness	14 pin Grey
C108	Coolant Temp send unit
C109	ECT	2 pin Grey
C111	O2	4 pin Grey	All but VX
C111	O2	8 pin Grey	VX
C117	EVAP	2 pin Grey
C112	VSS	3 pin Grey
C114	TPS	3 pin Grey
C115	IACV	2 pin Grey
C116	IAT	2 pin White
C106	Distributor	2 pin Grey	Ign Coil
C107	Distributor	8 pin Grey	TDC/CKP/CYP
C104	Starter Solenoid	1 pin Black
C119	Alternator	4 pin Green
C127	Vtec Solenoid	1 pin Grey	VX/EX/Si
C128	Vtec Pressure	2 pin Green	VX/EX/Si
C130	EGR Lift Sensor	3 pin Grey	VX
C113	MAP	3 pin Grey	CX/VX/EX/Si (CDM EX-V)
C201	MAP	3 pin Grey	DX/LX (93 Firewall)
C404	ECM	26 pin Grey
C405	ECM	16 pin Grey
C406	ECM	22 pin Grey
C120	Injector 1 (A1)	2 pin Grey
C121	Injector 2 (A3)	2 pin Grey
C122	Injector 3 (A4)	2 pin Grey
C123	Injector 4 (A2)	2 pin Grey
C118	Oil Pressure Switch	1 pin Black
C110	MT Backup Lght Switch	2 pin Grey
C110	AT Lock up Solenoid	2 pin Grey
Non VX	Label	Wire Colors	Route/Connections
C101-1	ECU Injectors	Red	C404-2 Red ECU A3 to C121-1 Red Injector 2
C101-2	ECU Injectors	Brn	C404-1 Brn ECU A1 to C120-1 Brn Injector 1
C101-3	ECU Injectors	Yel	C404-14 Yel ECU A2 to C123-1 Yel Injector 4
C101-4	ECU Injectors	Lt Blu	C404-3 Lt Blu ECU A5 to C122-1 Lt Blu Injector 3
C102-1	Ground ECU/G101	Brn/Blk	C405-9 Brn/Blk ECU B2 to G101 Brn/Blk
C102-2	O2 Sensor	Wht	C406-18 Wht ECU D14 O2 Input to C111-1 Wht O2 Signal
C102-3	Ground ECU/G101	Blk/Red	C404-26 Blk/Red ECU A26 Ground to G101 Blk/Red
C102-4	ECU CYP/Distributor	Orn	C405-6 Orn ECU CYP B11 to C107-4 Orn Distributor CYP
C102-5	ECU CYP/Distributor	Wht	C405-14 Wht ECU CYP B12 to C107-8 Wht Distributor CYP
C102-6	ECU TDC/Distributor	Orn/Blu	C405-7 Orn/Blu ECU TDC B13 to C107-3 Orn/Blu
C102-7	ECU TDC/Distributor	Wht/Blu	C405-15 Wht/Blu ECU TDC B14 to C107-7 Wht/Blu
C102-8	ECU CKP/Distributor	Blu/Grn	C405-8 Blu/Grn ECU CKP B15 to C107-2 Blu/Grn
C102-9	ECU CKP/Distributor	Blu/Yel	C405-16 Blu/Yel ECU CKP B16 to C107-6 Blu/Yel
C102-10
C103-1
C103-2	O2 ECU ground	Orn/Blk	C111-4 Orn/Blk O2 Heater to C404-16 Orn/Blk ECU A6 Heater control (ground)
C103-3	Vtec Solenoid	Orn/Wht - Grn/Yel	C404-15 Orn/Wht ECU A4 Vtec Solenoid to C127-1 Grn/Yel Vtec Solenoid
C103-4	MAP signal	Grn/Blu - Grn/Wht	C406-11 Grn/Blu ECU D21 MAP input to C113-2 Grn/Wht MAP
C103-5	MAP ground	Pnk/Wht - Wht	C406-9 Pnk/Wht ECU D17 sensor ground to C113-3 Wht MAP
C103-6	MAP ref volt	Yel/Grn - Yel/Red	C406-10 Yel/Grn ECU D19 reference voltage to C113-1 Yel/Red MAP
C103-7	Vtec Pressure Switch	Orn/Blu - Blu/Blk	C406-14 Orn/Blu ECU D6 Vtec pressure switch input to C128-1 Blu/Blk Vtec pressure switch
C103-8	TPS signal	Pnk/Blk - Red/Blu	C406-6 Pnk/Blk ECU D11 TPS input to C114-2 Red/Blu TPS
C103-9	ECU Sensor Ground	Grn/Wht	C406-22 Grn/Wht ECU D22 Sensor Ground to C111-2 (O2 Signal|), C109-2 (ECT), C116-1 (IAT), C114-1 (TPS), C424-2 (Service Connector) (All Grn/Wht)
C103-10	TPS ref volt	Yel/Wht	C406-21 Yel/Wht ECU D20 TPS reference voltage to C114-3 Yel/Wht TPS
C103-11	Ignition Output Signal	Red/Grn - Yel/Grn	C404-11 Red/Grn ECU A21 and C404-24 Red/Green ECU A22 Ignition Output Signal to C107-1 Yel/Grn Distributor
C103-12	IAT	Red/Yel	C406-8 Red/Yel ECU D15 IAT input to C116-2 Red/Yel IAT
C103-13	ECT	Red/Wht	C406-7 Red/Wht ECU D13 ECT input to C109-1 Red/Wht ECT
C103-14
C111-1	O2 Signal	Wht	C102-2 Wht Tower Plug (C102-2 Wht goes to C406-18 ECU D14 O2 Input
C111-2	O2 Signal	Grn - Grn/Wht	O2 Grn to C103-9 Grn/Wht Tower Plug (C103-9 goes to C406-22 ECU D22 sensor Ground)
C111-3	O2 Heater Power	Yel/Blk - Blk	C125-6 Yel/Blk Power Junction to O2 Blk Heater
C111-4	O2 Heater Ground	Grn/Blk	O2 Blk Heater to C103-2 Grn/Blk Tower Plug (C103-2 goes to C404-16 ECU A6 Heater Control)
C124-1
C124-2
C125-1	Junction (Power)	Yel/Blk	C122-2 Yel/Blk (Injector 3)
C125-2	Junction (Power)	Yel/Blk	C121-2 Yel/Blk (Injector 2)
C125-3	Junction (Power)	Yel/Blk	C120-2 Yel/Blk (Injector 1)
C125-4	Junction (Power)	Yel/Blk	C126-12 Yel/Blk
C125-5	Junction (Power)	Yel/Blk	C115-2 Yel/Blk (IACV)
C125-6	Junction (Power)	Yel/Blk	C111-3 Yel/Blk (HO2 Heater)
C125-7	Junction (Power)	Yel/Blk	C117-1 Yel/Blk (EVAP)
C125-8	Junction (Power)	Yel/Blk	C123-2 Yel/Blk (Injector 4)
C126-1
C126-2
C126-3	EVAP	Red - Red/Blk (Coupe-Red)	C117-2 Red EVAP Valve to C302-5 Red/Blk (Coupe-Red) Cabin Harness to ECU
C126-4	IACV	Blu/Yel - Grn/White	C115-1 Blu/Yel IACV to C302-2 Grn/Wht Cabin Harness to ECU
C126-5	VSS	Blk/Yel - Yel/Blu	C302-3 Blk/Yel Cabin Harness (From Fuse Box) to C112-2 Yel/Blu VSS
C126-6	VSS	Yel/Blu - Yel/Wht	C302-8 Yel/Blu Cabin Harness (From ECU B10) to C112-3 Yel/Wht VSS
C126-7
C126-8
C126-9
C126-10
C126-11
C126-12		Yel/Blk	C302-13(Main Relay) - C125-4 Yel/Blk
C126-13
C126-14
VX	Label	Wire Colors	Route/Connections
C101-1	ECU Injectors	Red	C404-2 Red ECU A3 to C121-1 Red Injector 2
C101-2	ECU Injectors	Brn	C404-1 Brn ECU A1 to C120-1 Brn Injector 1
C101-3	ECU Injectors	Yel	C404-14 Yel ECU A2 to C123-1 Yel Injector 4
C101-4	ECU Injectors	Lt Blu	C404-3 Lt Blu ECU A5 to C122-1 Lt Blu Injector 3
C102-1	Ground ECU/G101	Brn/Blk	C405-9 Brn/Blk ECU B2 to G101 Brn/Blk
C102-2
C102-3	Ground ECU/G101	Blk/Red	C404-26 Blk/Red ECU A26 Ground to G101 Blk/Red
C102-4	ECU CYP/Distributor	Orn	C405-6 Orn ECU CYP B11 to C107-4 Orn Distributor CYP
C102-5	ECU CYP/Distributor	Wht	C405-14 Wht ECU CYP B12 to C107-8 Wht Distributor CYP
C102-6	ECU TDC/Distributor	Orn/Blu	C405-7 Orn/Blu ECU TDC B13 to C107-3 Orn/Blu
C102-7	ECU TDC/Distributor	Wht/Blu	C405-15 Wht/Blu ECU TDC B14 to C107-7 Wht/Blu
C102-8	ECU CKP/Distributor	Blu/Grn	C405-8 Blu/Grn ECU CKP B15 to C107-2 Blu/Grn
C102-9	ECU CKP/Distributor	Blu/Yel	C405-16 Blu/Yel ECU CKP B16 to C107-6 Blu/Yel
C102-10
C103-1
C103-2	O2 ECU power	Orn/Blk-Yel/Blk	C404-16 Orn/Blk ECU A6 Heater Control (power) to C111-1 Yel/Blk O2 Heater
C103-3	VTEC	Orn/Wht - Grn/Yel	C404-15 Grn/Wht ECU A4 Vtec Solenoid Control to C127-1 Grn/Yel Vtec Solenoid
C103-4	ECU MAP	Grn/Blu - Grn/Wht	C404-11 Grn/Blu ECU D21 to C113-2 Grn/Wht MAP
C103-5	ECU MAP	Pnk/Wht - Wht	C404-9 Pnk/Wht ECU D17 to C113-3 Wht MAP
C103-6	ECU MAP	Yel/Grn - Yel/Red	C404-10 Yel/Grn ECU D19 to C113-1 Yel/Red MAP
C103-7	VTEC	Orn/Blu - Blu/Blk	C404-14 Orn/Blu ECU D6 Vtec Pressure Switch Input to C128-1 Blu/Blk Vtec Pressure Switch
C103-8	ECU TPS input	Pnk/Blk - Red/Blu	C405-6 Pnk/Blk ECU to C114-2 Red/Blu TPS
C103-9	ECU Sensors ground	Grn/Wht	C111-3(O2 Heater2),C130-1(EGR Lift Sensor),C114-1(TPS),C116-1(AIT),C109-2(ECT),C424-2(Service Check Connector) (All Grn/Wht)
C103-10	ECU Refence Voltage	Yel/Wht	C406-21 Yel/Wht ECU to C114-3 Yel/Wht TPS
C103-11	ECU Igntion Output Signal	Red/Grn - Yel/Grn	C404-24 Red/Grn ECU A22 and C404-11 Red/Grn ECU A21 to C107-1 Yel/Grn Distributor ICM
C103-12	ECU IAT Input	Red/Yel	C406-8 Red/Yel ECU to C116-2 Red/Yel IAT
C103-13	ECU ECT Input	Red/Wht	C406-7 Red/Wht ECU to C109-1 Red/Wht ECT
C103-14
C129-1	LT EGR	Yel/Wht	C406-21 Yel/Wht Ecu Reference Voltage EGR/TPS D20 to C130-3 Yel/Wht EGR lift sensor
C129-2	LT O2	Wht/Blu	C406-15 Wht/Blu Ecu O2 Sensor Input D8 to C111-6 Wht/Blu - Red
C129-3	LT O2	Blu/Yel - Wht	C406-2 Blu/Yel Ecu O2 Heater D3 to C111-4 Wht
C129-4	LT EGR	Wht/Blk	C406-17 Wht/Blk Ecu EGR lift sensor input D12 to C130-2 Wht/Blk Egr lift sensor
C129-5	LT O2	Blu/Grn - Orn	C406-19 Blu/Grn Ecu O2 Signal Ground D16 to C111-8 Orn - Blk
C129-6	LT O2	Orn/Blu	C406-18 Orn/Blu Ecu O2 Sensor Input D14 to C111-7 Orn/Blu - Wht
C111-1	O2 Power	yel/Blk - Orn	C103-2 Orn/Blk - Yel/Blk to O2 Heater 1 - C404-16 ECU A6 to O2
C111-2	O2 Ground	Yel - Blk	G101 - O2 Heater to G101
C111-3	O2 Ground	Blk - Grn/Wht	C103-9 Grn/Wht O2 Heater - C406-22 ECU (Sensor Ground)
C111-4	O2 Power	Wht	C129-3 Blu/Yel - Wht to O2 Heater 2 - C406-2 ECU to O2
C111-5	O2
C111-6	O2 Signal	Wht/Blu - Red	C129-2 Wht/Blu to O2 Signal - C406-15 ECU to O2
C111-7	O2 Signal	Orn/Blu - Wht	C129-6 Orn/Blu to O2 Signal - C406-18 ECU to O2
C111-8	O2 Signal	Orn - Blk	C129-5 Blu/Grn - Orn to O2 Signal - C406-19 ECU to O2
C124-1
C124-2
C125-1	Junction (Power)	Yel/Blk	C122-2 Yel/Blk (Injector 3)
C125-2	Junction (Power)	Yel/Blk	C121-2 Yel/Blk (Injector 2)
C125-3	Junction (Power)	Yel/Blk	C120-2 Yel/Blk (Injector 1)
C125-4	Junction (Power)	Yel/Blk	C126-12 Yel/Blk
C125-5	Junction (Power)	Yel/Blk	C115-2 Yel/Blk (IACV)
C125-6
C125-7	Junction (Power)	Yel/Blk	C117-1 Yel/Blk (EVAP)
C125-8	Junction (Power)	Yel/Blk	C123-2 Yel/Blk (Injector 4)
C126-1
C126-2
C126-3	EVAP	Red - Red/Blk (Coupe-Red)	C117-2 Red EVAP Valve to C302-5 Red/Blk (Coupe-Red) Cabin Harness to ECU
C126-4	IACV	Blu/Yel - Grn/White	C115-1 Blu/Yel IACV to C302-2 Grn/Wht Cabin Harness to ECU
C126-5	VSS	Blk/Yel - Yel/Blu	C112-2 Yel/Blu VSS to C302-3 Blk/Yel Cabin Harness to Power (Fusebox)
C126-6	VSS	Yel/Wht - Yel/Blu	C112-3 Yel/Wht VSS to C302-8 Yel/Blu Cabin Harness to ECU/CCU/Gauges
C126-7
C126-8
C126-9
C126-10
C126-11
C126-12		Yel/Blk	C302-13(Main Relay) - C125-4 Yel/Blk
C126-13
C126-14

C107 is the distributor plug with the CYP, CKP and TDC sensor. Which goes to the C102 tower plug.

 

Of note, you've changed the distributor and it has not corrected the issue. There could also be an issue with the shielding on the CYP wires between C107 and C102. The shielding is grounded to G101 on the thermostat. If that connection is broken the shielding of the CYP wires is ineffective and could be causing you your grief.