The more I read the more confused I get! I've done some reading and searching on various threads, and forums. I'm more confused than when I started haha.

D16Z6 dizzy's are specific to their motors, because of the way the bolts are spaced to the Z6 head. Thus, you cannot use any other dizzy, nor can you use a Z6 dizzy on any other motor.

Mini me swaps that use a Z6 head need to use a Z6 dizzy for the same reasons. The most common swap (I think?) is D15Bx (x standing for whatever number) block and a Z6 head.

Now, the tricky stuff. OBD2 dizzy's are also specific because of their plugs. You cannot use an OBD2 dizzy on a OBD1 chassis without modifying the plugs/ wires. OBD1 motors/ dizzy's to OBD2 chassis are easier due to being able to easily find a jumper harness you can use. Same applies to OBD0 to OBD1 I suppose (I have a CRX with a Z6 someone swapped using a harness).

BUT, using an OBD2 dizzy on a OBD1 chassis? I haven't had any luck finding such a jumper harness. I've thought about making one myself, or just... swap the housings? Which is where I'm getting confused!

The specific application;

I have a jdm D15B 3-stage VTEC motor, that had an OBD2 dizzy, going into an OBD1 chassis (and ECU). I tried using a Z6 dizzy but the bolts didn't line up (unless I failed miserably?). RIght now, I'm using a D15B7 dizzy, which SEEMS to work just fine, bolts right up perfectly. However, using a stock P28 ECU, I can't rev it higher than 6500 rpm. I used to be able to rev my D16Z6 up to 7200 rpm like normal, before I swapped it.

My questions;

1. Does the dizzy have some sort of rev limit set in place?
2. IF SO, can I swap Z6 internals into the B7 (or even the original jdm D15B) housing to fix this?
3. IF NOT, what else could be causing this 6500 rpm rev limit, given the ECU is stock?

 

If I recall, you can swap the internals of the Z6 into a B7. But it might be something as simple as a wire in the wrong position in one of the plugs. I will take a closer look tomorrow. I have both the TD-41U and the TD-42U as well as an ETM to get the downlow on the obd1 distributors. The D15Z1 (Vtec-e) motor uses the same dizzy as teh D16Z6. Guess the 3 stage JDM D15B comes with the non vtec head bolt pattern?

If I may ask, how are you getting all 3 stages working with a P28 ECU?

Another tidbit that may cause challenges. OBD1 motors are 16* BTDC ignition timing. OBD2 motors are 12* BTDC ignition timing motors. I know cam shafts have a slightly different slot orientation likely due to the 12 degree/16 degree design. The distributors may also have slightly different magnet lobe orientation to correlate to this. I've never compared the distributor shafts between OBD1 and OBD2 to see if there is any change beyond the shaft index.

 

Well... I'm not, not yet anyway haha. I have the normal VTEC plugged in, normally. I depinned the 2 wire plug, and made it a 1 pin like a USDM single VTEC plug normally is, and plugged it into the harness. The first stage isn't wired to anything at all at the moment. I plan on using a VTEC controller to activate it at approximately 2500 - 3000 rpms, but I'll run into fueling issues. It'll still be sending the same amount of fuel regardless of how many valves are open, right? I'd imagine something like a VAFC Apexi or whatever might've been more useful, but for the money, I'd rather chip and reflash my ecu. I've seen a couple of people mention using the IAB function of the P72 (P75? Whatever the GSR one is) to control the first stage VTEC.

I've also read some people just using Hondata and it's NOS function to control it that way as well...? I really have no idea. VTEC controller for now, but ultimately I might just end up swapping the head.

This is some good info to know, I'll dig around and research some more. This might be what is giving me trouble.

I've also noticed, I'm getting awful mpg's. I got to about 220 miles on a little over 8 gallons (full tank). I used to get between 300 - 350 miles!

 

Sorry I didn't look this up last weekend like I mentioned I was going to. I did look a bit tonight though as I had to look up what pin I had to move back to the proper plug in my VX to put the D15Z1 engine back in. To do that I had to find my post where I mapped out the tower plugs found in this post here.

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 Engine 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

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

Now from the table, the distributor has an 8 pin and a 2 pin plug, doesn't matter if it's the TD41U for the CX/DX or the TD42U for the VX/Si.

Non VX:
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
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

There is only 7 pins in the 8 pin connector on both Distributors.

VX (same distributor as the Si) no difference in distributor, just in shock tower by 1 pin:
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
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

And the two pin had the exact same colors between the two, it's the power and ground for the coil.

So that means you can just swap between the TD41U and the TD42U as needed. Now to swap internals with an OBD2 distributor, you will need the same basic information provided above to see if it relates and to repin etc.