j30 just died


zaskar_ofn
12-11-2004, 12:40 AM
my J30 has 196000 and it was running perfectly up to a couple of days ago. I started the vehicle and it cranked fine, the engine ran for about 3 seconds and then it died. the day before I made a long trip, 1000 miles round trip with no problems what so ever. I had the engine rebuild 3000 miles ago. and so I don't think any of the work done could have caused this problem. I guess my question is, where is the ECU and how do I get the car to give me error codes? engine cranks but it does not start. there are no blown fuses. any ideas ? there is fuel pressure pass the fuel filter, that was my first check. and like I said the car/engine was running fine up to 2 days ago. could it had been the computer?

Nahkapohjola
12-11-2004, 03:54 AM
my J30 has 196000 and it was running perfectly up to a couple of days ago. I started the vehicle and it cranked fine, the engine ran for about 3 seconds and then it died. the day before I made a long trip, 1000 miles round trip with no problems what so ever. I had the engine rebuild 3000 miles ago. and so I don't think any of the work done could have caused this problem. I guess my question is, where is the ECU and how do I get the car to give me error codes? engine cranks but it does not start. there are no blown fuses. any ideas ? there is fuel pressure pass the fuel filter, that was my first check. and like I said the car/engine was running fine up to 2 days ago. could it had been the computer?

engine rebuild ... I don't think any of the work done could have caused this problem.
- I dont think so. Most propably it has...

ECU (beside gas pedal) controls just about everything. Buy chilton manual for the ECU.

Propabilities
- Ingnition totally dead. Is there 12V at coil? Spark? (take wire out, insert any spark plug, ground it, watch for sprk while cranking) ECU drives thsi process...
- No injector pulse from ECU to injectors =no gas to burn...
- Some crucial signal (not sensor) to ECU is down. Ign key sends one. Is the sw worn out?
- etc.


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ECU instructions can be best found on Chilton/Haynes manual (20$?), also some places in the net. ECU is located just beside the gas pedal. Try finding info here:

http://www.newshampark.org.uk/bignissansold/j30/

http://www.maxima.org/

http://www.parttrackers.com/library/1/93/104/
This has a long story on troubleshooting:
Here Parts from it:

But if all that is okay, and/or the Check Engine light is on (Nissans didn't get this warning device until '88 for California and '89 federally), the next logical step is to engage the self-diagnostics. Unlike most other carmakers, Nissan has you go right to the ECU for this. Remove it from the passenger's side kick panel, then find the mode selector screw and the port in the housing through which a red and a green LED are visible.

Switch on the ignition, turn the selector screw clockwise all the way, and watch the LEDs. They'll flash once, then pause, twice then pause, and on up to five times to indicate the five diagnostic modes. When you see the number of the mode you want, turn the screw counter-clockwise.

*Modes & codes

Mode 1 is called the "Exhaust Gas Sensor Monitor" because it informs you about oxygen sensor activity. With the engine running and fully warmed up, the green LED should blink, going on when the sensor sends a lean signal and off when it sends a rich signal. You should see 5-10 flashes every 10 seconds. If the LED is on more than it's off, there's a lean condition, and vice versa. Sluggish blinking should make you suspect a fouled sensor.

Mode 2, the Mixture Ratio Feedback Control Monitor, lets you know whether or not the air/fuel mixture is being controlled within the proper range. If the red and green LED's flash pretty much simultaneously with the engine running, mix control is okay. If the red LED is off more often than the green one, richness is indicated. If the red is on more than its mate, think lean.

Mode 3 has the name "Self-Diagnostic," and it's more what you're used to on other vehicles because it yields fault codes, both hard and intermittent, which are communicated to you by means of the flashing of both LED's. The red one gives the first digit, and the green one the second digit. For instance, if the red flashes twice, then the green flashes once, you've got a Code 21.

Get the engine up to normal temp, preferably by driving the car for 10 minutes, then pull the codes. In the case of a no-start, crank the engine for at least two seconds. If you see 55, all is well (in older models, 44 meant the same thing). Be sure to write down any other codes because they'll be erased when you go on to Mode 4, which means you will have lost any help on intermittents. Normally, codes are retained in memory for fifty starts.

Mode 4, called the "Switches On/Off Diagnostic Mode," checks the function of the switches that serve as inputs to the ECU, specifically those for ignition key start position, idle, and vehicle speed. For the first two, the red LED will go on or off when switch status is changed. In other words, with the ignition on, the red light should illuminate both when you step on the gas pedal and when you turn the key to start. If not, check the appropriate circuit. The vehicle speed sensor lights the green LED when you exceed 12 mph (get the drive wheels off the floor to do this in the shop, or have a helper drive while you keep your eyes on the ECU).

Mode 5 ("Real-Time") gives instantaneous trouble codes to let you know what's going on right now in four monitored circuits. Codes are flashed out just once when a malfunction is detected, then they're immediately forgotten. And the way you read them is different -- you observe the flashing of one LED or the other, the red one reporting on the crank angle sensor and the fuel pump circuits, and the green on the air flow meter and ignition signal circuits.

If the red LED pulses out a series of long flashes separated by equally long pauses, a malfunction in the crank angle sensor or its circuit's indicated. Groups of three short flashes of the red LED point to the fuel pump or its circuit. With the green LED, two medium flashes followed by a pause, then two again, and so on, should cause you to suspect the air flow meter and its related wiring. Groups of four flashes mean there's a problem with the ignition signal.

This is an extremely sensitive and very useful mode. You can wiggle wires and connectors, rap on components, and have somebody else drive the car while you watch for those fleeting indications of trouble. You'll know everything's okay if you see no flashing in five minutes of revving and idling.



ECU Codes:
11 Crank Angle Sensor/Camshaft Position Sensor.
12 Air Flow Meter/Mass Air Flow Sensor.
13 Engine Coolant Temperature Sensor.
14 Vehicle Speed Sensor.
21 Ignition Signal.
22 Fuel Pump.
23 Idle Switch.
24 Throttle Valve Switch.
25 Idle Speed Control Valve.
28 Cooling Fan Circuit.
31 ECM.
32 EGR Function.
33 Heated Oxygen Sensor.
34 Knock Sensor.
35 Exhaust Gas Temperature Sensor.
36 EGR Control-Back Pressure Transducer.
37 Knock Sensor.
38 Right hand bank Closed Loop (B2).
41 Intake Air Temperature Sensor.
42 Fuel Temperature Sensor.
43 Throttle Position Sensor.
45 Injector Leak.
47 Crankshaft Position Sensor.
51 Injector Circuit.
53 Oxygen Sensor.
54 A/T Control.
55 No Malfunction.
63 No. 6 Cylinder Misfire.
64 No. 5 Cylinder Misfire.
65 No. 4 Cylinder Misfire.
66 No. 3 Cylinder Misfire.
67 No. 2 Cylinder Misfire.
68 No. 1 Cylinder Misfire.
71 Random Misfire.
72 TWC Function right hand bank.
73 TWC Function right hand bank.
76 Fuel Injection System Function right hand bank.
77 Rear Heated Oxygen Sensor Circuit.
82 Crankshaft Position Sensor.
84 A/T Diagnosis Communication Line.
85 VTC Solenoid Valve Circuit.
86 Fuel Injection System Function right hand bank.
87 Canister Control Solenoid Valve Circuit.
91 Front Heated Oxygen Sensor Heater Circuit right hand bank.
94 TCC Solenoid Valve.
95 Crankshaft Position Sensor.
98 Engine Coolant Temperature Sensor.
101 Front Heated Oxygen Sensor Heater Circuit right hand bank.
103 Park/Neutral Position Switch Circuit.
105 EGR and EGR Canister Control Solenoid Valve Circuit.
108 Canister Purge Control Valve Circuit.

zaskar_ofn
12-11-2004, 05:59 AM
holly cow, that's some great info.
I tested the spark and we got fire ( trick with a spare HT wire and a strobe lgiht) so we are not getting fuel into the cylinders.
about the rebuild there were things done to the engine that it would have shown problems right from the begining. the intake was ported, all seals and gaskets were replaced, EGR valve and piping where cleaned/replaced. new plugs, tranny flushed, with new filter and new fluid. timing belt/idle pulleys,... all of this past the new break in period...
I'll start with the computer and its error codes, hopefully it'll give me clues.
thanks again.

zaskar_ofn
12-12-2004, 11:05 PM
I finally had time to troubleshoot the car. I went straight for the computer, dismounted the unit from the bracket to expose the turn knob, set the computer for test diagnostics and waited for error codes... There were none. set computer for diagnostics II and again no errors. So I decided to crank the engine and it ran fine...
now what??? it works. has anybody had anything like this happening?

Nahkapohjola
12-13-2004, 03:15 AM
Now most propably you have some bad connections or broken wires that moved as u worked with the ECU. If its -in- the ECU, sorry, get new...

However, 90% of faults are on connectors, outside.

Do like this: open the connetcors (seek info how). Take white paper (better cardboard) and clean all connector pins on cable and on ECU. Most propably they'll come out with dark oxidation...
Close all and hope...


If you decide to get new, looking inside (and possibly ruining rest) will not take away anything. There might be something loose inside or you detect cold soldering point on some connector or conpoment on the pcb (use magnifier).

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