CALLING ALL THE EXPERTS!!!

[rbspitfire]

ok this is a continuation of a previous thread about my injectors not firing, well they still arent. both wires are getting power, but they arent getting grounded, the ecu is grounded and the injector grounds 107 108 and 116 are grounding what could it be every once in a while it will fire once, my guess is its just a slight leak in an injector. one thing i notied is the injector resistor doesnt have power to it, one white wire and one black wire, i assume one of them should??? IT HAS TO BE A GROUNDING ISSUE, BUT WHERE?? the injectors get their ground from the ecu, where does the ecu get its ground from, sensors, being mounted..???the car is solid mounted so there wont be any issues with ground straps. any help will get you points with the man upstairs!!

[Darius]

What motor is this for?

[l0nestar]

RB20

[rbspitfire]

yes its an rb20 sorry about that

[Sil240]

I have the same exact problem.I have switched ECU's, I changed the injectors this past weekend. I have NO clue why the hell it doesn't work.I've got power on both sides of the injector clips/leads but its not being grounded out.Who wired your harness for you??

[rbspitfire]

i did all my wiring, ran fine for months, washed the engine took it around the block made a u-turn and pushed it home.

[Darius]

This is a stupid question, but have you checked your fuses?

[Sil240]

Here's my symptoms- From my post on SDU

RB20DET into a S13 (KA24E) USDMRB20DET - Problem Fuel Injectors do not fire!!!!!!!Cranks and cranks and that is all.It does not burp, fart or spit.Has sparkCAS works at least with sparkFuel Pressure is presentFuel lines are correctExhaust cam key has broken off inside of the CAS.Tried to get it out and glue it, but it is stuck inside.Lined up the CAS according to the broken area on the cam.But car doesn't even give me a fart, flame or a burp.

Green Relays click when I turn the key and thats it.Fuel pump turns on with or without Green relays installed.Does anyone else's car work the same way??

I have power at the injector leads all the time. (Batt voltage)But have no grounding from the ECU.Have tried jumping the harness, (taking wires from right out of the ECU straight to the injectors.

If you have any information please let me know

Brian [email protected]

I haven't been able to go work on my car, but i did look up a couple things.I found that the ECU has several grounds through the harness.http://www.plxdevices.com/ECUD...nd%22Would the injectors not work if the ECU wasn't bolted down??

The car hasn't been running for a long long time.I believe all the fuses are good, but hey I'll check again.

[rbspitfire]

it wouldnt be a fuse or relay would it if the injectors are getting power??

[Carl H]

the way that nissan wires the car is that sensors get power and the ecu gives ground.i would try a diffrent ecu if possible to see if the ecu isnt fried.

[S14-NEO]

you need to make sure your start signal fuse is not popped...thats the main fuse that can kill fuel..you need to get a noid light and check to se if your injectors are firing...

[rbspitfire]

where is the start signal fuse? i have torn apart the harness and didnt see any fuseable links or anything i did see a relay looking thing in the center of this pic

[rbspitfire]

ok, the ignition start signal #43 out of the ecu doesnt have any power, should it??

[S14-NEO]

there should be power going to the start signal yes...not sure what pin number it is but there should def be power there

[S14-NEO]

this isnt ina 240 chassis correct?

[FAST-DATSUN]

Go to Pep Boys or other large Auto Parts store and get a NOD light install it into each injector clip. if it does not flash and you have 12v to the power side of the clip then the injector driver is probly bad if you have good grounds. the computer through the driver grounds the injector making it work, its gets its siginal from the CAS same signal for the spark.....

[Sil240]

I'm gonna go buy a Noid light set tonight.I found on a Advance Auto for $18.00Probably this weekend I'm gonna try it on my car. I figure my CAS is definetly working because I have Spark. So I hope its just a ground and not 2 blown ECU's

http://www.plxdevices.com/ECUD...8.pdfSo I should make sure that Pin #'s:10, 20, 50, 60, 107, 108, & 116 Are grounded.Right??If they are grounded properly and the Noid light still doesn't blink then the Injector driver in my ECU's are fried.

Could the Injector Resistor cause the injectors not to fire also?? I believe I took a multimeter to it and it was in spec, but it' been a long time.

[rbspitfire]

ok this is getting weird, or a REALLY big coincidence, i got power to the start signal, it took a while cranking but finally got started and was smoking, blue,white,grey,black,you name it i pulled off the radiator cap when it was cold and POOOF antifreeze shower, the headgasket must have been hurt or something. where can i get a good deal on a headgasket and studs, or headbolts?????

[the_momo]

oh crap i hope it isnt a headgasket. youll be best off taking it apart and decking the head and block, then doing metal hg and arp studs. failsafe. but do a comp test to determine if its a hg or rings or something

oh and btw thanks for the injectors, i got them today!

good luck hope its nothing major.

[Sil240]

If the motor was cold and you open the rad and antifreeze exploded like that, then you definetly are losing compression into the water jacket.

That is a weird coincidence.Because I have the same exact symptoms that you have, but my motor is Brand spanking new never been ran before.

Ebay has ARP stud kits and HG's.I've heard Takakira was a good place to get stuff. (never bought from them though)

Maybe the coolant sensor is bad, would that cut the fuel??? Maybe the ECU thinks that the motor is overheating and wont fire the injectors so it doesnt kill the motor.

I'll test that this weekend too.Does anyone know what Coolant sensor the RB20 uses?? Z32?

[Carl H]

a bad coolant temp sensor wont always throw a code but can run super rich and be hard to start.

[lyon23]

He never did say if he checked to see if he was getting a signal on the noid lights. If your not getting one and your wiring is right I would open the ecu and see the resistors for the injectors. I got a computer that had burned up resistors.

[Sil240]

What coolant temp sensor does the RB20 run?

Tomorrow I'm gonna try and test the injector leads to see if there's a signal.I know there isn't but I want to be sure.I know the Injectors are good for sure, I took them all out and tested them with the batt, they all fired.

Lyon-What do the resistors look like??I'm gonna test all the grounds as well.I don't think its that. Hopefully it will be, but I don't think so. Do you think I could take out and re-solder new resistors in?? If they are bad??

Also if there was no IC piping, the car would still start right??I have the MAF coupled to the TB.It should start, if not fully start try to start and run shytty.

[rbspitfire]

CARL H is there a way to test the coolant temp sensor, i ve been searching and seen that you have mentioned that many times, but havent seen if theres a way to test it? i would think resistance, but dont know what values

[Sil240]

Ok,Tested the ECU grounds and they are good.I opened up the ecu and i see one of the little (diode,resistor,capacitor) or whatever it is looks kind of burnt under it.SUCKS!!!!

Is there anyone in the South Florida area with a RB20 in a S chassis?? I want to check my ecu's before I buy one, and I'm not sure what I'm gonna do because I dont know if my harness is miswired and fried the ecu's (2).

Is there anyway that I can test my harness to make sure that its not shorting out my ECU??I'm guessing break out the multimeter and check every circut huh????

Because if I have to buy a new ecu, I might as well just buy a RB25 PFC.

To test the Engine Coolant sensor.On the coolant wire clip, there are 2 wires.If you are looking at the clip, the wire on the left is #1 and the one to the right is #2.You need to test the resistance between them.Approx 2.5K Ohms when cold.Approx .3K Ohms after warming up.

[Sil240]

Lyon23-What do the resistors look like??Do you think I could take out and re-solder new resistors in?? If they are bad??

I opened up my 2 ecu's and there is a Red/Black tiny little pill looking component in there. The component itself doesn't look burnt but the board under it looks a little bit burnt ON BOTH. None of the other parts that I could see look like that.

Also if there was no IC piping, the car would still start right??It should start, if not fully start try to start and run shytty.I have the MAF coupled to the TB.

[Carl H]

2 dead ecus?something is wrong with the wiring then...it should start if you connect the maf to the j pipe.

[Sil240]

Jon Powell wired my harness for me.He said there could of been 2 ways he could of done it.1- Direct to the battery (+ connection all the time)2- To the ignition switch (+ connection whenever the key is on)

I did put the battery on backwards once.Which could of done it.But I think it got it blown from VENUS AUTO.Because my car was doing the same exact thing like 1.5 years ago. The other chipped ecu came from a guy in Germany. I never tested it, but now and before(1.5 yr ago) it still doesnt work.

I had to put the MAF on the TB, because I have the Top Hat plenum. Good thing I got it as well, because of the number of times i've messed with those damn injectors.

I'm gonna get another ECU hopefully this weekend and try it. But I'm gonna check the harness for any shorts first before I blow another computer.

[rbspitfire]

send me one of youre ecu's and ill test it , obviously ill pay for shipping before you spend more money on another ecu, youll be helping both of us.

[Sil240]

I think they are both blown.I can see a little bit of a burnt mark on both of them.

Ok, so i couldn't get the new ecu this weekend apparantly there open on Sat by appt.

But i yanked the harness out of the car and started to probe. It sucks it sucks it sucks.I hate wiring!!!!!!!

But i started testing and looking through the R32 manual. I found that it keeps on refering to the resistor pack as having 6 wires.If what I have is the resistor pack it only has 2 wires.

Can anyone confirm this for me??It looks like a silver rectangle with two tabs on it to bolt it to the firewall or somewhere.It has two wires on it looks like they are wrapped in kinda nylon or some kinda shoe lace looking thing.

So I decide to test the resistance of this "resistor pack" and It says I'm supposed to get 5 ohms (on the 6 wire pack), but I get nothing.It doesn't even register.

If the resistor pack is blown or unplugged (in a working cars case) would the injectors then not fire??

If someone could check for me if they could just pull the wire harness to their resistor pack and then try to start the car.

So i guess I have one more part to pick up.Or maybe its just that.