DOHC ZC in hatch and runs like poo

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Biggz

New Member
I just got a car from a buddy of mine you tried to swap in a DOHC ZC. The car is a 1991 ef hatchback Si. Here is some of the issue with the car that have me concerned. The fuel rail and injectors are off of a d16z6, with the resistor box removed. The throttle body has a TPS but it also has the MAP sensor on the firewall too, he has the plug plugged into the TPS. The motor has no cam angle sensor, he said it was built into the dizzy. I tend to beleive that the dizzy is a OBD1 dizzy. When i start the car up, it runs like poo. I can hold the pedal to the floor and in spits and spudders and if it can muster the strength it will rev to like 3k RPM and then sound like it is banging off the rev limiter. Sometimes I can rev it but even if i hold the pedal wide open, it will not gain RPMs at all just hovers around 1800 rpm. The harness is hacked up but I dont mind soldering to fix the harness. The dizzy has the plug cut off along with the dizzy plug on the harness and spliced in. The main question I have can I use the OBD1 dizzy and the ODB0 harness, and if so what colors do I splice together. Also do i need the cam angle sensor. And can i use the injectors without the resistor box. I appreciate all the help I can get, cause this thing is needs to be my daily driver.
 
the engine is probably the 92-95 JDM OBD1 DOHC ZC which has OBD1 injectors and a fuel rail just like a D16Z6, does not have a CYL sensor on the end of the exhaust camshaft, has a TD43U distributor (number stamped on the side of one of the attaching arms), has the MAP sensor on top of the throttle body, uses a 4-rib alternator belt, has the cooling fan switch on the thermostat housing and has a slightly different timing belt cover from the OBD0 ZC - you should have the connector for the MAP (which was originally on the firewall) plugged into the MAP on top of the throttle body

you can tell the year of the engine by looking at the numbers cast into the head between the #2 and #3 exhaust ports:

OBD1ZCheadyear.jpg


what ECU is in it? if it has the OBD1 TD43U distributor, it has to have an OBD1 ECU (factory OBD1 DOHC ZC ECU is P29) in order to run correctly, which would mean that it also has to have an OBD0 to OBD1 ECU jumper harness

the spark plug wires should be in this order:

zcfiringorder2-3.jpg
 
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i have a 89 integra ecu on its way. Is there a way to run a obd0 dizzy on it. and if so what do i need the dizzy from
 
i have a 89 integra ecu on its way. Is there a way to run a obd0 dizzy on it. and if so what do i need the dizzy from
if you want to run it OBD0, you need the distributor and the CYlinder sensor (which goes on the end of the exhaust camshaft) from 88-89 Integra - the distributor is a TD03U - you would need the distributor connector for the engine harness from 88-89 Integra or 88-91 CRX/Civic DX/LX/STD - the distributor connector has 5-wires in it - just match the wire colors on both sides of the connector - you need to be careful with this as there are 2 white wires - the white wire for the igniter should be connected to the yellow/green on the OBD1 distributor that is in it now - the connector has the wires like this:

DXCONN-5.jpg


when you get that connector installed on the harness, you will have 2 wires left over on the harness - should be blue with green stripe and blue with yellow stripe - extend these wires to the 2-pin green plug on the CYL sensor on the exhaust cam, again matching color for color
 
another thing you might want to check is to see that the cooling fan switch is connected - on the OBD0 engine, it is on the back of the block next to the oil filter and on the OBD1 engine, it is on the thermostat housing - it has 2 wires, a black and a yellow with green stripe and they would have needed to put a 2-wire connector on the harness in order to plug it in at the thermostat housing switch
 
so i plugged in the 1988 teg ecu and now it wont even start. I have come to the conclusion that i need a good si engine harness and a good obd0 dohc zc dizzy. so if you have any cheap pm me, cause I really, really want to drive this god forsaken thing.
 
read what he told you, do what he says... it will save you from just buying parts like your planning...
 
so i plugged in the 1988 teg ecu and now it wont even start. I have come to the conclusion that i need a good si engine harness and a good obd0 dohc zc dizzy. so if you have any cheap pm me, cause I really, really want to drive this god forsaken thing.
what ECU was in it before? are you sure that the PG7 you put in was from 88-89 and not 86-87?
 
It had a pm4 in it before. I ordered the ecu off ebay and it was listed for a 1989. is there a way to tell besides trusting some nob off fo ebay?
 
correction pm9. i found a bundle of blue wires on the passenger side of the car that are cut. Are they important to the function of the car?
 
double checked the block is stamped 92. And there is a plug in on the thermostat housing. I will get a list of the random cut or unplugged wires here in a few. Is there anyone who has a wire schematic for a 1991 si?, so I can track down part of these wires
 
It had a pm4 in it before. I ordered the ecu off ebay and it was listed for a 1989. is there a way to tell besides trusting some nob off fo ebay?
this is 88-89 PG7 ECU - has smooth top cover

number for manual transmission should be 37820-PG7-A0## or 37820-PG7-L0##

number for automatic transmission should be 37820-PG7-A1## or 37820-PG7-L1##

88pg7-1.jpg


this is 86-87 PG7 ECU - has stamped 'X' across cover

number for manual transmission should be 37820-PG7-66## or 37820-PG7-68##

number for automatic transmission should be 37820-PG7-67## or 37820-PG7-69##

87PG7-3.jpg
 
it is a 37820-PG7-L0##. But it has since come to attention that the dizzy is a obd1 dizzy, so I assume that is why it does not work when I plug it in. Since this is the case, I have an extra engine harness for a d15 obd1 coupe. Can i get this to work since the motor and the dizzy is obd1. I am thinking it should plug right in where my old hacked harness is. And just to clarify, I love HS.
 
it is a 37820-PG7-L0##. But it has since come to attention that the dizzy is a obd1 dizzy, so I assume that is why it does not work when I plug it in. Since this is the case, I have an extra engine harness for a d15 obd1 coupe. Can i get this to work since the motor and the dizzy is obd1. I am thinking it should plug right in where my old hacked harness is. And just to clarify, I love HS.
the OBD1 engine harness will not work on your car - you either need to convert the engine to OBD0 or convert the car to OBD1 - see my posts #2 and #4 in this thread
 
Okay so I am a dumbass, I can admit it now. I want to go OBD1 so when i boost it later on I can use Hondata or something along those lines, to adjust everything. I have got a whole 1993 dx d15 obd1 harness that is good. I have a obd1 dizzy, and a obd1 motor. So I can use the stock obd0 engine harness and buy the dizzy plug adapter and the ecu adapter and its a plug and play deal. I am i right or am I totally wrong again, and I actually need the obd1 engine harness?????
 
hey i have obdo distributor and ecu and second cam sensor. if you have obdo car this will be pefrect. i just put zc motor in my obd1 car which is a del sol so i got to go obd1 with my stuff so all the obdo stuff i have just sitting here. if you need it hit me up
 
hey i have obdo distributor and ecu and second cam sensor. if you have obdo car this will be pefrect. i just put zc motor in my obd1 car which is a del sol so i got to go obd1 with my stuff so all the obdo stuff i have just sitting here. if you need it hit me up

I might be interested in the distributor and cam sensor if it hasn't been sold...
 
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