Ok so now is it actually a fuel problem. Can you smell fuel in the exhaust when trying to start?
Are you getting spark?
Are you getting spark?
No power to fuel pump
Hi, I have a 1991 MR2 turbo with a 4th gen 3sgte. Engine is fully rebuilt and engine harness from Doug (wiregap). Prior to getting the engine harness I was getting no power to the fuel. I was hoping the new harness might fix it so I can rule that out. The only problem I do have with this harness is that the obd scanner won’t turn on with it. My previous harness I was able to get codes. I replaced the efi relay and the COR still no power to the fuel pump. I only get 1v instead of the 12. I tested the starter relay and the ign relay all passed the testing procedure. I also checked all the fuses up front and replaced the 120a one. The starter is also new as well as the alternator. When I connected the fuel pump straight to the battery it would start right up without shutting off. So my car only starts with starter fluid or if I wire the fuel pump straight to battery. The only thing I changed prior to it not starting was the pipe that goes from the turbo to the side Intercooler. The connector that’s behind the driver seat is also plugged in, battery is also new. All the grounds are connected too, I sanded down the paint just Incase too. Anything else I should look for that could prevent power going to the fuel pump?
Thanks
Thanks
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Yeah I smell fuel, it starts for a bit when I spray starter fluid then shuts off. When I connected the F/P straight to the battery it started right up too.Ok so now is it actually a fuel problem. Can you smell fuel in the exhaust when trying to start?
Are you getting spark?
Ok right. It is fuel.
Can you test the circuit from Pin 1 on the Circuit Opening Relay to the fuel pump resistor relay pin 5. By default the GEN2 3SGTE runs power to the resistor so you need to have the FPR pin on the ECU ground to make it switch to bypass the resistor for a full 12V.
Page 61 has the rest of the diagram. I don't recall if you have the relay and resistor noted as Fuel Pump Relay F2 and Fuel Pump Resistor F1.
![Rectangle Schematic Slope Font Parallel]()
![Rectangle Slope Font Schematic Parallel]()
Can you test the circuit from Pin 1 on the Circuit Opening Relay to the fuel pump resistor relay pin 5. By default the GEN2 3SGTE runs power to the resistor so you need to have the FPR pin on the ECU ground to make it switch to bypass the resistor for a full 12V.
Page 61 has the rest of the diagram. I don't recall if you have the relay and resistor noted as Fuel Pump Relay F2 and Fuel Pump Resistor F1.
According to his early reply, he doesn’t have the F/P relay and resistor pack.Ok right. It is fuel.
Can you test the circuit from Pin 1 on the Circuit Opening Relay to the fuel pump resistor relay pin 5. By default the GEN2 3SGTE runs power to the resistor so you need to have the FPR pin on the ECU ground to make it switch to bypass the resistor for a full 12V.
Page 61 has the rest of the diagram. I don't recall if you have the relay and resistor noted as Fuel Pump Relay F2 and Fuel Pump Resistor F1.
View attachment 87082 View attachment 87083
Do what I did, I’m sure others have done it.
Run an aftermarket relay from an IGN source straight to the F/P connector. Use a thick gauge wire while you are at it.
Those two grey plugs on the bottom, correct that.. make sure that BOTH plugs are in the same orientation.I tried it and it wouldn’t start.
I got the car with the swap in already but it ran and it drove. I installed the swap back in after getting the engine rebuilt. It started and drove after as well.
I was having a high idling problem though
View attachment 87073
View attachment 87074
I don’t have the fuel pump relay and resistor pack. If that’s what you’re referring to about the fuel pump resistor relay pin 5Ok right. It is fuel.
Can you test the circuit from Pin 1 on the Circuit Opening Relay to the fuel pump resistor relay pin 5. By default the GEN2 3SGTE runs power to the resistor so you need to have the FPR pin on the ECU ground to make it switch to bypass the resistor for a full 12V.
Page 61 has the rest of the diagram. I don't recall if you have the relay and resistor noted as Fuel Pump Relay F2 and Fuel Pump Resistor F1.
View attachment 87082 View attachment 87083
Those plugs connect to each other, I found it strange when I was connecting the harness up but that’s how it’s suppose to be lolThose two grey plugs on the bottom, correct that.. make sure that BOTH plugs are in the same orientation.
Yes I understand that’s how it’s suppose to be. However I really meant it when I said put both plugs in the SAME orientation. Refer to my picture of the grey / white plug at the bottom.Those plugs connect to each other, I found it strange when I was connecting the harness up but that’s how it’s suppose to be lol
Ohhhh ok I understand now, I’ll do thatYes I understand that’s how it’s suppose to be. However I really meant it when I said put both plugs in the SAME orientation. Refer to my picture of the grey / white plug at the bottom.
View attachment 87090
P0002- Fuel volume regulator control circuit range performance
Can that be the reason why it’s not getting power?
Can that be the reason why it’s not getting power?
GEN4 ECUs seem to be OK for capacitors right now. Not old enough or a different good batch of parts used.
Ok. Reading back I see you note that.I don’t have the fuel pump relay and resistor pack. If that’s what you’re referring to about the fuel pump resistor relay pin 5
Ok so we need to determine why the fuel pump isn't getting power with the key in the start position. Are you able to check continuity from the fuse box to the fuel pump. Pin 1 on the C/OPN relay should go direct to the pump. Blue with black wire.
There is a plug behind the left seat that joins the left side body harness to the centre body harness for the pump.
Sorry I've been taking a while. Had trouble logging in.
Ok so I checked for continuity and I was getting OL on the connector that plugs in with the F/P and I checked the plug behind the driver seat. That was getting OL as wellOk. Reading back I see you note that.
Ok so we need to determine why the fuel pump isn't getting power with the key in the start position. Are you able to check continuity from the fuse box to the fuel pump. Pin 1 on the C/OPN relay should go direct to the pump. Blue with black wire.
There is a plug behind the left seat that joins the left side body harness to the centre body harness for the pump.
Sorry I've been taking a while. Had trouble logging in.
OL means no connection.Ok so I checked for continuity and I was getting OL on the connector that plugs in with the F/P and I checked the plug behind the driver seat. That was getting OL as well
So do you believe the disconnect is between the seat plug and fuse box?
I honestly don’t know where the disconnect could be coming from. Prior to it not starting I didn’t mess with the wiring at all, I didn’t even know that plug was behind the driver seat until I started looking into this problem.OL means no connection.
So do you believe the disconnect is between the seat plug and fuse box?
P0002- Fuel volume regulator control circuit range performance
I don’t know if that could be the problem as well
That's just the pump resistor relay you don't have as it is removed from the GEN4 harness. A normal code to have for a GEN4 swap.I honestly don’t know where the disconnect could be coming from. Prior to it not starting I didn’t mess with the wiring at all, I didn’t even know that plug was behind the driver seat until I started looking into this problem.
P0002- Fuel volume regulator control circuit range performance
I don’t know if that could be the problem as well
You need to trace the blue with black wire from the Circuit Opening Relay to the pump and find the break in it.
EFI Main Relay is defective.
I replaced that already and still the same problem.EFI Main Relay is defective.
Yeah I’m gonna have to trace it, it’s pin 4? I can test the continuity by putting the lead on pin 4 and the power on the F/P connector? Also can the ignition main relay be the problem? That’s the only relay I haven’t replaced.That's just the pump resistor relay you don't have as it is removed from the GEN4 harness. A normal code to have for a GEN4 swap.
You need to trace the blue with black wire from the Circuit Opening Relay to the pump and find the break in it.
21 - 40 of 52 Posts
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