Help Please!!!!!!
#1
04-25-2010, 06:22 PM
Help Please!!!!!!
I swaped my 1992 3vz-fe engine for a 1994 1mz-fe and im having problems with the 28 pin plug for the engine computer. Is there a universal wiring harnest i can buy or is there something else that i can do?
#2
04-26-2010, 11:35 PM
Suggest you do a Google search on "swapping 3VZ-FE for 1MZ-FE"
The resulting posts state this is a difficult swap.
One issue is the computer is very specific to engine type, trans, emissions, year, etc. You should be able to find a computer a 1MZ-FE computer for the 1994 cheap enough. Try Ebay or junk yards.
The 1992 and 94 are of the same generation Camry, the wiring may be the same or pretty close.
You might also ask at the Toyotanation website.
The resulting posts state this is a difficult swap.
One issue is the computer is very specific to engine type, trans, emissions, year, etc. You should be able to find a computer a 1MZ-FE computer for the 1994 cheap enough. Try Ebay or junk yards.
The 1992 and 94 are of the same generation Camry, the wiring may be the same or pretty close.
You might also ask at the Toyotanation website.
#6
04-29-2010, 08:54 PM
This would be harder to find.
The Autozone website has some wiring diagrams in their self help vehicle repair guide section.
See if your local library subscribes to AllData. This is a service that independent mechanics use to access auto data.
The Autozone website has some wiring diagrams in their self help vehicle repair guide section.
See if your local library subscribes to AllData. This is a service that independent mechanics use to access auto data.
#8
05-05-2010, 09:12 AM
Not sure. Never heard of it on Camry.
Keep in mind before the pump will stay on, the fuel pump relay (called Circuit Opening Relay COR)) needs to be receiving a signal that the engine is running.
If the engine has a MAF sensor, the sensor may have a vane switch that closes when air is flowing to keep the relay powered. On older Camry this switch may have been connected directly to the COR.
There is also another circuit that allows the pump to run when the engine is cranking. This circuit depends on the engine type. But typically picks up a signal from the ign system that it is working,
The 1994 1MZ-FE seems to route everything through the computer.
The COR would pick up its signals from the computer. The MAP switch would be connected to the computer, the ign signal would route to the computer. The computer would send a signal to the COR that the engine was cranking or running.
Keep in mind before the pump will stay on, the fuel pump relay (called Circuit Opening Relay COR)) needs to be receiving a signal that the engine is running.
If the engine has a MAF sensor, the sensor may have a vane switch that closes when air is flowing to keep the relay powered. On older Camry this switch may have been connected directly to the COR.
There is also another circuit that allows the pump to run when the engine is cranking. This circuit depends on the engine type. But typically picks up a signal from the ign system that it is working,
The 1994 1MZ-FE seems to route everything through the computer.
The COR would pick up its signals from the computer. The MAP switch would be connected to the computer, the ign signal would route to the computer. The computer would send a signal to the COR that the engine was cranking or running.
#9
05-29-2010, 08:33 PM
Ok feeling better have spark and engine turns on if I jump the fuel pump,but the fuel pump does not turn on with the ignition switch. checked open relay and the efi main relay both work fine.
#10
05-30-2010, 11:33 AM
When the FP and B+ terminals are jumped power is applied directly to the fuel pump. All relays, etc are bypassed.
On the 1MZ-FE system, when the ign key is turned to start a couple of things happen.
One is power from the ign key switch flows through the Park/Neutral switch (assuming the trans is in park/Neutral) or if clutch switch for a manual trans. This power goes to through the Starter Relay solenoid then to ground.
When the Starter Relay switch is closed power flows from the battery to the 40A Main fuse and through the Starter Relay contacts. This power splits off to the Starter Solenoid on the Starter Motor AND through the 10A Start fuse to the Circuit Opening Relay solenoid (COR) and then to ground.
When the COR contact switch closes power flows to the pump and then ground. This is the same power that is at the B+ terminal in the Diagnostic box.
As stated previously the COR has 2 separate solenoids that can power the same relay switch. One was explained above. The second solenoid is powered when the engine is running.
This allows the pump to be powered after the ign key is turned from start to run.
One terminal of the second solenoid coil is connected to the same power wire that runs to the B+ terminal and thus has 12V. There appears to be an internal connection inside the COR box that does this connection.
All that is needed for this second solenoid to activate is the other end of the coil to be grounded but this other end runs to the computer.
The MAF sensor is connected to the ECU. It appears to have a vane switch that closes when there is air flow in the intake (engine running).
It appears once this vane switch is closed the ECU grounds the wire running from the solenoid on the COR to complete the circuit and power the solenoid.
I don't know if the other engines MAF sensor you swapped out has this vane switch.
Sometimes a system is used that picks up signals from the ignition systems igniter that tells the ECU the engine is running.
On the 1MZ-FE system, when the ign key is turned to start a couple of things happen.
One is power from the ign key switch flows through the Park/Neutral switch (assuming the trans is in park/Neutral) or if clutch switch for a manual trans. This power goes to through the Starter Relay solenoid then to ground.
When the Starter Relay switch is closed power flows from the battery to the 40A Main fuse and through the Starter Relay contacts. This power splits off to the Starter Solenoid on the Starter Motor AND through the 10A Start fuse to the Circuit Opening Relay solenoid (COR) and then to ground.
When the COR contact switch closes power flows to the pump and then ground. This is the same power that is at the B+ terminal in the Diagnostic box.
As stated previously the COR has 2 separate solenoids that can power the same relay switch. One was explained above. The second solenoid is powered when the engine is running.
This allows the pump to be powered after the ign key is turned from start to run.
One terminal of the second solenoid coil is connected to the same power wire that runs to the B+ terminal and thus has 12V. There appears to be an internal connection inside the COR box that does this connection.
All that is needed for this second solenoid to activate is the other end of the coil to be grounded but this other end runs to the computer.
The MAF sensor is connected to the ECU. It appears to have a vane switch that closes when there is air flow in the intake (engine running).
It appears once this vane switch is closed the ECU grounds the wire running from the solenoid on the COR to complete the circuit and power the solenoid.
I don't know if the other engines MAF sensor you swapped out has this vane switch.
Sometimes a system is used that picks up signals from the ignition systems igniter that tells the ECU the engine is running.