1JZ error code 31 and no power to fuel pump?? (edit: now coil problems)

[Jabtronic]

Hi all,
I've done a 1JZ engine conversion into an MX83 Cressida, and am having problems getting the car running.

There are two things that are happening.
1. Error code 31
2. ECU not supplying power to the fuel pump (FP pinout)

What do I need to do to diagnose error 31? And could it be what is causing the ECU to not provide power the pump? When I bridge +B and FP the pump runs and the car starts and idles.

As far as I know, the ECU is fine as I bought another one and it made no difference.

What else should I check?

Any help would be appreciated, thanks.

[Jabtronic]

Added a bit more information.

[FASTFOO]

What car was the 1JZ from and is it of the type that uses a seperat fuel pump computer (controller) ?
Code 31 is map/boost sensor so check that pim makes it all the way to the computer. (fuel pump should go when cranking anyway)
MATT.

[Jabtronic]

Was from a JZA70, no idea if it used a fuel pump controller because the 1JZ was already converted into another MX83 before mine. As far as I know it ran fine without it.

Might just post up a cross link to the same thread I've posted on supraforums.com.au for any reference.
http://www.supraforums.com.au/forum/...ad.php?t=34051

Which pin am I checking? (pim as in PIM?.. or just a typo?) And where does it have to go to?


Sorry about my newbness to this wiring stuff, I understand the general stuff but not the more compicated stuff. I sent the car to an autoelectrician just in case and he checked it all but I don't think he really knew what he was doing.

The fuel pump doesn't go when cranking or when the key is initially turned to on, only when I hard wire it by bridging +B and FP in the diagnostics plug.

[EldarO]

7M (GTE im sure of, dunno about GE, 90% sure) use the same fuel pump relay, so what you need is there already.

you need to hook up the fuel pump relay via the big square plug (has 3 fairly hefty wires in the centre) that plug into the panel behind the glove box.

what have you hooked up there? and what wires do you have hanging loose?

draw up a little MS paint diagrams of what yu have on the 1JZ engine loom, and what you have on the standard MX83 plug, that you should've cut off the 7MGE loom, and mated onto the 1JZ engine loom.

Elmo.

[Jabtronic]

And here's how the body plug is wired up. I noticed pins 9 and 10 shouldn't have anything in them? Will have to check what those 2 wires do on the MX83 plug.



Note the car is a manual, manual ecu, and no aircon or cruise control. Hopefully this pics come in handy to solving this.

[Mos]

The fuel pump wire is the FC pin (X14 on your diagram) - this controls the circuit opening relay.

The FPR pin (FP on your diagram X16) controls the fuel pump relay, which shorts out the fuel pump resistor which you should remove and short out - on the MX83 the fuel pump resistor is on the RH strut tower - you should remove this resistor and short out the two wires that go to it. If you have unplugged this resistor and not shorted the wires, the fuel pump will not run and not prime.

The FP pin (diagnostic connector) is the output of the fuel pump relay and circuit opening relay - it's not a signal wire.

Mos.

[Jabtronic]

Ah ok thanks, will have a look for the resistor tomorrow, I'm sure the wires havn't been short together, so hopefully that fixes the fuel pump problem.

From memory, is the resistor the small black cylinder on the RH strut?

Also would would anybody be able to tell me what the silver rectangular heatsink looking thing is on the MX83?

[madmont]

When i did my conversion to 2JZ i pulled the circuit opening relay and connected the output of my fuel pump ecu to the fuel pump wire which went to the check connector . From memory the pump resistor is in an alloy housing. Yours does not appear to have the fuel pump ecu and the wiring would be very similar to the MX83 using the fuel pump relay and circuit opening relay. The MX83 circuit opening relay has an input from the air flow meter . Have you looked at that ? Also has signal from starter. The circuit opening relay needs either an earth (green wire from the airflow meter) or 12v from start circuit to close and supply 12v to the fuel pump relay.If you short out the green wire to earth you will have power to the fuel pump relay. The ECU signal to the fuel pump relay slows the fuel pump. If the ECU is not connected to the fuel pump relay the pump will run at full speed constantly.

[Mos]

Ah ok thanks, will have a look for the resistor tomorrow, I'm sure the wires havn't been short together, so hopefully that fixes the fuel pump problem.

From memory, is the resistor the small black cylinder on the RH strut?

Huh? What small black cylinder?

Also would would anybody be able to tell me what the silver rectangular heatsink looking thing is on the MX83?

Bingo - that should be the resistor - should be 0.73 ohms, on the driver's side strut tower.

If the resistor is still there, chances are you haven't hooked up the FC pin correctly.

Mos.

[cambelt]

With the mx83 fuel pump relay , just leave it in and dont connect anything to the FPR wire, you can just pull the pump resister out . The normally closed position of the FP relay runs the pump at full voltage .
Dave

[Jabtronic]

Ok, thanks for all the info. Got the fuel pump working, I couldn't get it to work any other way than grounding the circuit opening relay. I tried grounding the resistor wires, shorting them together.. disconnected the FPR pin etc none of that worked?

So anyway the fuel pump works, car still wont start.

I cleared the code 31 by removing the Blitz FCD that was wired into the PIM line. (For now.. I'll work out what was wrong with that once the engine is running.

BUT now I'm getting error 14, which is the Ignition Signal Circuit... I found this http://mkiv.supras.org.nz/articles/engine_2_14.htm

I'll try diagnosing tomorrow. The car is now cranking, firing but then stalling. Seems to be ignition related anyhow.

[Jabtronic]

Ok, found the problem, there's no spark from the 5th coil. But it's not the spark plug or the coilpack. It's something to do with the plug, wiring or the ignitor.

The 5th coilpack plug has a yellow/green wire and black earth wire.
Using a multimeter, the yellow/green wire goes back to the yellow/green to the ignitor, the black wire is grounded the same as the other plugs.

All the IGT1-6 wires go from the ECU to the ignitor plug properly, and they all receive a tiny amount of voltage (0 - 1v) while cranking. So what else could it be??

Before I find and test another ignitor, is there anything else I can check? Can I hook the multimeter up to the 5th coilpack plug and get a reading from it?

[Mos]

The 5th coilpack plug has a yellow/green wire and black earth wire.
Using a multimeter, the yellow/green wire goes back to the yellow/green to the ignitor, the black wire is grounded the same as the other plugs.

This black wire is likely to be black-red or black-yellow but not plain black (iirc), and it should have 12V on it and not ground. The igniter grounds the yellow/green.

Mos.

[Jabtronic]

Just went and checked it then, the black wire is getting 12volts with the ignition ON. I couldn't test if the ignitor was switching the ground because it's too late to crank the car so I'll try that in the morning. Thanks.