hey guys just did a self test on the ecu and came up with the following 12=AFM 13=Coolant Temp Sensor ( just replaced it) 14=Speed Sensor 21=ignition signal 23= throttle switch 24= neutral switch 34= knock sensor ( not running one) 31 aircon ( not installed) i did a test on the afm and its showing 1.25v why could the temp sensor not be working. problem with loom ??? any help would be great car is running very rough . all the plugs are black as. and are only maybe a few hours old ---------- Post added 22-01-12 at 15:42 ---------- well just replaced the plugs and its idling perfect. so what is causing the plugs to foul up

You've pretty much answered your own question...... Sounds like there's a problem with the CTS wiring. Since you've replaced the sensor, it must be in the loom or plug. I'd say it's open circuit...the ecu interprets this as really cold so it will be adding a stack more fuel than required.

hey guys did a test with the mutlimeter on the coolant temp sensor and when i put the mutlimeter on the plug to meaure omhs. the idle drops down a bit . when i take the multimeter off. the revs pick up, could this be a break in the wiring

The internal resistance of the Multimeter is causing the ECU to read a temperature. What ECU do you have? all 6 VL ECU have different results. The Sensor, should read 1800ohms at room temperature and around 350ohms warm. The DTC '12' is a problem if it still comes up when the engine is running.

i have the 3tm ecu but i think ive fixed the problem with the cts i gave the contact points a clean and the cts seems to be working. when plugged in the car idles quiet low. when unplugged the idel jumps up a bit. now to fix the other problems

ok, in that case, also test after 4 minutes of warmup, unplugging the CTS should not make any difference to idle speed.

Quote: Originally Posted by bachig24u [View Post] ok, in that case, also test after 4 minutes of warmup, unplugging the CTS should not make any difference to idle speed. You sure about that?? I thought unplugging it makes it run rich as the ecu thinks the engine is cold? That's why it was playing up in the first place.

it depends on which version of ECU is being used.

if the coolant temp sensor isnt working would this cause the car to run so rich it would foul the plugs and i can smell petrol really bad. and one other thing i noticed is when i pull of the fuel line that go's into the rail there is no pressure build up is this normal

Might be abit pissed ATM but, doesn't the air & fuel ratio control your richness or leanness. So I'd be looking at either your fuel or your air intake. ie (blocked injectors or fuel pressure) Just another question. Are you running a RB30E plenum or a RB30ET plenum.

lol all good injectors are reco items.running a rb30et plenum

Quote: Originally Posted by Wkd_Vl [View Post] hey guys just did a self test on the ecu and came up with the following 12=AFM 13=Coolant Temp Sensor ( just replaced it) 14=Speed Sensor 21=ignition signal 23= throttle switch 24= neutral switch 34= knock sensor ( not running one) 31 aircon ( not installed) i did a test on the afm and its showing 1.25v why could the temp sensor not be working. problem with loom ??? any help would be great car is running very rough . all the plugs are black as. and are only maybe a few hours old ---------- Post added 22-01-12 at 15:42 ---------- well just replaced the plugs and its idling perfect. so what is causing the plugs to foul up Also to cancel these code. AFM = it's either faulty or working Coolant temp sensor = either faulty or working try wiggling the connector Speed senor circuit = drive the car greater then 15 kmph & it will cancel the code. throttle switch = depress the throttle pedal twice to cancel the code ignition circuit = Start the ignition once or twice to cancel the code neutral switch = place the car into drive then neutral/park twice knock senor = problem because you don't have one (might be running lean) air con = problem because you don't have one (ignore) ---------- Post added 28-02-12 at 20:30 ---------- Quote: Originally Posted by Wkd_Vl [View Post] lol all good injectors are reco items.running a rb30et plenum Wicked, sorry M8 for the late reply LOL. Some original photos have not been recovered yet.

all good. im going to run the test again as i picked up another afm and the coolant temp sensor is new but i think it could be the plug or loom ill also put a multimeter on the afm and see what ohms im getting

Quote: Originally Posted by Wkd_Vl [View Post] if the coolant temp sensor isnt working would this cause the car to run so rich it would foul the plugs and i can smell petrol really bad. and one other thing i noticed is when i pull of the fuel line that go's into the rail there is no pressure build up is this normal the nice fuel aroma is probably a fuel leak, fairly common when the injector seals are old. ---------- Post added 29-02-12 at 08:22 ---------- Quote: Originally Posted by Wkd_Vl [View Post] if the coolant temp sensor isnt working would this cause the car to run so rich it would foul the plugs and i can smell petrol really bad. and one other thing i noticed is when i pull of the fuel line that go's into the rail there is no pressure build up is this normal it could be low on fuel or the CTS is fubar, it can foul plugs when turbo seals are gone or running really rich if the engine thinks its really cold. sounds like a fuel pressure issue causing initial problem, then all the cranking has caused the fuel smell and fowled the plugs.

yes i think i might have a pressure issue. im going to try pick up a fuel pressure gauge soon. but i guess maybe when the car is drivable it may give the plugs a chance to burn the unused fuel ---------- Post added 29-02-12 at 17:46 ---------- well ive just done another ecu test. first i wiped the ecu clear of any previous codes and re run it and came up with 14= speed sensor 23=throttle switch 24=neutral switch 31=aircon 34=knock sensor also did a test with the afm it was showing 2volts witch from what ive read is rich so i adjusted it to 3volts 3.6 volts is meant to be factory. so ill see how i go anyway of testing the fuel reg

You'll allways have these codes, 14= speed sensor 23=throttle switch 24=neutral switch 31=aircon Unless you cancel them

Quote: Originally Posted by Wkd_Vl [View Post] yes i think i might have a pressure issue. im going to try pick up a fuel pressure gauge soon. but i guess maybe when the car is drivable it may give the plugs a chance to burn the unused fuel ---------- Post added 29-02-12 at 17:46 ---------- well ive just done another ecu test. first i wiped the ecu clear of any previous codes and re run it and came up with 14= speed sensor 23=throttle switch 24=neutral switch 31=aircon 34=knock sensor also did a test with the afm it was showing 2volts witch from what ive read is rich so i adjusted it to 3volts 3.6 volts is meant to be factory. so ill see how i go anyway of testing the fuel reg tip: if you suspect fuel pressure issue due to pump supply or fuel filter blockage etc, clamp the return line and prime the system using the ign reds twice (10 secs apart). Once primed, the fuel pressure should hold in the line at no less than 22psi or the engine will be a bitch to start at the best of times. if it holds pressure then the oneway check valve is working ok, if it doesn't hold pressure, maybe replace/install a check valve or pump. if it can't get pressure up to around 30 whilst pumps are priming then need to investigate, pumps/lines/filters. as for the MAF: Set your Multimeter to ohms, low range, around 2k or similar. unplug MAF and test the resistance between the first and last pins. (1 and 6) The resistance should measure 382ohms, its the bench mark for stoichiometric mixture given your are using 95-98ron pump fuel. the screw adjustment will only affect idle mixture and very light throttle driving. you really don't want to deviate too far from 382ohms as it affects fuel economy a fair bit. up to 500 is probably ok any more and you may as well disconnect the 0xygen sensor (ego) and adjust the mixture by listening for the typical missen nissan popping sound to determine if its too lean or not.

one thing i havnt installed yet is the fuel dampner would this have a affect on the fuel supply and ill try the ohms reading and see what it comes up with cheers again mate

Quote: Originally Posted by Wkd_Vl [View Post] one thing i havnt installed yet is the fuel dampner would this have a affect on the fuel supply and ill try the ohms reading and see what it comes up with cheers again mate there is a fuel dampers in the VL from memory.. at the rear, next to the HPress pump, sits before the filter. this one can be removed/bypassed as its diaphram is probably rotten anyway. if its of adequate size, eg. matching the fuel line for instance. its ok, but I would definitely remove the 20+yr old one under the car. I am in favour of fuel dampers as they have a small but relevant purpose, only problem is that they often become a restriction when pushing 400+horses.

well just did the ohms test and it was sitting on 500 and ive adjusted it to 382