Rb20 s14 starts then dies STUMPED
 

Info on the car: 96 s14 originally manual non abs got as a roller with tubbed and painted engine bay. Because of this i had to relocate the underhood fuse box (put it in the arm reast) and battery (trunk). The only wires i messed with for the fuse box were extending the headlight wires around the driver side fender to the housings. All others were left alone and re plugged in.

Info on the swap: stock everything exept ls coils and act clutch. Main maintenance done on it oil water pump and all that. Wiring specialties pro harness with ls coil pack adapter oem ecu. O2 sensor unplugged because the previous connector melted together so i had to cut the wires to get the old harness off. Vss not hooked up and boost solenoid not hooked up either all of which i feel are unrelated.

Condition:car starts fine first crank but immediately dies after, wont even idle. Note im mostly working by myself so i couldnt open the trottle while starting or spray starter fluid in the intake due to the throttle cable needing to be swapped out.

At first the car wouldnt start at all. Did test found out it wasnt getting 12v to the starter signal wire so i jumped that relay and brought it to this situation. I dont know much about the under hood fuse box but the starter relay has two wires on the controll side one thats green and white that recieves 12v when in start and a small black and yellow on that doesnt seem to do anything. Tested the relay itself and its fine. I have no idea what this black and yellow wire goes to and why its not grounding to activate the starter relay. Which is what i think the cause of this situation is.

I jumped this relays controll side to get power to the starter signal when key is on start position but i think what ever section of the under hood fuse box isnt getting ground or power is also keeping it from idling when the key is in the on position. BUT!!! I checked all 3 grounds that this fuse box had and they are all connected and good. I also made sure the two large white wires on the back of the box were getting full 12v from the battery and they are. Am i leaving something un powered? I followed this black and yellow wire through the harnes to another relay under the dash where it had 2 black and yellow wires coming out the output. That relay tested fine too but after that i have no idea what comes before that

For shits and giggles i tested spark which it has and fuel which i believe it has. Pump primes and holds 40psi, unhooked the lines and it sprayed fuel into a bucket. I doubt its compression. Checked with maf unplugged and with it plugged in no change has a new k&n filter on it. Made sure i had no vaccume leaks or anything. Brand new battery like a week old ect.

Unless my fuel lines are hooked up wrong which i doubt but am open to it being a possibility i believe something isnt getting power or ground in the underhood fuse box. But i have nothing to compare it to again im doing all this by myself. If someone could tell me what gets a full 12v from the battery in this fuse box i feel like that might fix my problem.

side note the fuse box isnt in the casing anymore so i have easy access to the side terminals where there are 2 white and red wires on one terminal that i put to 12v. There is a black terminal that was cut before i got the car, tried to ground it and burnt the wire so i believe thats power but its not connected to anything at all. There is a terminal with a bolt that after i put 12v to it caused the windows and interior lights to work. And there is one white and red wire that goes under the fusebox seprate from the other 2. These are the only main connections i can see.

I feel like im rambling on but im truly stumped right now and im trying to get this thing running for a show in 10 days.

Small update, unplugged tps sensor to see if that was it. No change. Tested to see if injectors were getting 12v which they are. Found a handful of blown fuses, replaced them no change.

That second relay mentioned above has a black and white wire and a black and pink wire on the controll side the white gets 12v going to try and follow the pink one to see where it grounds.

Pictures of the engine bay would help

As for your fuel lines: does it go from the filter, into the rail, then through the FPR, then into the return? RB fuel rail outputs are really close together so easily mixed up

So, make sure it doesn't go from fuel filter to FPR

If ur lines were reveresed, it would start at all.....

Once it starts will it rev up at all? Or just crank..start...sputter.. die?

Fresh fuel filter when doing the swap?

Might pay to pop the return line from the rail into a bucket to see if fuel is making it through. Cycle the key a couple of times to prime it

Try unplugging the coolant temp sensor for the ecu and see how it runs.

I tried to add pictures it wont let me but ill try again. Currently its set up as feed line through filter into fpr then into the motor and return is just a line going back.

As soon as it turns over it dies immediately cant even test if it will rev up went to try starter fluid today but now it wint even crank i think the starter just went on it

Yes and ill have to try that when i get it cranking again, i assumed yes because whenever i swapped lines it would be fule in the return line too

Something to consider

Update: checked flash codes on ecu and im getting the code that i think means all clear (5 slow flashes and 5 fast flashes)

Car no longer cranks i think the starter is done i can hear it click but thats it. Checked baytery terminals and voltage, tapped on it the whole 9 but its kind of wierd because it was cranking very healthy before it just stopped

could the IAC cause this found the part where the connector is cracked to the point where it tries to hang off if you bend it a certain way, also have replacement starter coming tomorrow

Hang on, feed line is going through filter then into FPR?????

That's wrong way round dude. Swap them over

Fuel pump outlet-filter-fuel rail feed

Fuel rail outlet-fpr-gas tank return


Thats correct way

imma swap them tonight and pray it works in the morning when i put the new starter in. these lines were out of wack when i first got the car as a roller so ive been trying all combinations, previous owner set it up
feed - fpr - inlet
outlet - filter - return

Yea, the way u have it listed is backwards

Swapped lines and nothing still holds 40psi.
My rb20 has 2 lines coming off the front and no rear fpr
The top lone has a fpr the other doesnt.

The line that had the oem fpr is what i have return hooked up to and the bottom one is the one i have feed hooked to. New starter is in and im back to square 1 where it only just cranks

Okay....

Do you have spark? (Pull coil pack out insert spark plug and have the plug touching metal(aka ground) visiably see spark arking on the plug


Do you have injector pulse? On injector connector theres 2 wires..one wire will have a key on power. Make sure it does. The other wire will have a pulsing ground while cranking/running.

Check this and report back

Question: how do you know it holds 40psi if it has a stock FPR? Do you have a gauge on the feed line?

tested power wire to injectors in on position had 12v, didnt check ground tho
tested coils earlier by pulling the coil with the plug and checking spark. shocked myself cuz im a numbskull . but that confirmed spark

when i get out of my classes at 5 ill check the ground side of the injectors hopefully i can find someone to crank the car while i test stuff out :naw:
show is in 7 days and im starting to really get stressed out

Yes please check that pulsing ground on the injectors...lmk

Its not a stock fpr there anymore, i was just trying to describe my setup. I have one with a guage on it.

Ok, so it's:

Feed line - filter - fuel rail inlet (old outlet, where old FPR was) - fuel rail outlet (was old fuel rail inlet) - aftermarket FPR w/ gauge - return

They weren't wrong when they said a picture says a 1,000 words lol

Try taking the CAS plug off. Check the pins aren't bent and give them a good spray with contact cleaner

yea thats the current setup fuel line wise. ill check the cas as well when i get back really wish it would let me send the pictures i have im relatively new so idk if im doing it right or not but im trying to put them in as attachments. to the reply. ill keep trying tho

You'll need to use an image hosting site dude. Google "post image" and once you've uploaded it, copy the Direct Link URL and use that

Did a test on the ground wire of the injectors my multimeter showed 10v cranking im assuming its averaging it out. 12v on the power side at on the injecters in on position.

Sprayed fluid in the intake and it ran off that untill i stopped spraying (nice to hear how it sounds) so i know its fuel now i have 4 theories
-clogged injectors? But all 6 :naw: rubs me the wrong way
-clogged rail? But wouldnt any clogs increase my fuel pressure?
-bad gas? A friend of mine mentioned that the gas thats been sitting in the tank probably doesnt have enough octane in it to feed the car, i know nothing of this.
-need to upgrade fuel pump? I also feel like if this was the case it would run but just stall out or run really laggy

Okay u can use a test light( or noid light) u need to test ground circuit on the injectors, while cranking they should pulse the test light on and off....thats the injector driver opening and closing circuit.

Thanks hope this works
https://postimg.cc/qg2XytYT

The top line is the return im assuming which is going to fpr and back to the return on the s14
Bottem line that goes to the left is what i have hooked up to the feed comming through the filter

Your fuel lines are correct... were close to solving this...issue is injectors not firing...

Also if u remove the cam angle sensor, leave it plugged in, turn ley to ignition on, u can spin the cas by hand and u should hear the fuel injects clicking as u spin it....

So close!!!

Agree about removing the CAS and spinning it to see if the injectors click, but before that just try cleaning the contacts on the CAS plug first. Remember, the CAS plug needs to push on reasonable hard and clicks when fully seated (if the plug isn't broken)

If the plug contacts are cleaned & the injectors click when the CAS is spun, it may be worth pulling injectors to see if they're wet or dry.

If they're wet, and seeing as though it's not a stock harness, are you 100% the injector plugs are plugged into the right injectors?

Oh and when you want to post another photo, click the Image icon and enter the Direct Link url when prompted and it will embed

Like this:

https://i.postimg.cc/pV6GNzJp/20191008-101721.jpg

Ok so when i go back after work ill do the test light and check with the cas then update. I also forgot to mention that unplugging the cas had no change at all. So if i take that piece out and spin the shaft on it i can hear clicking where injection is supposed to occur via clicking or when someone is cranking the motor?

Unbolt the cas from the engine, leave it plugged into the harness.... turn key to ignition on(not cranking) and turn the cas. U should here injector clicking as u spin the cas.


But to 100% verify, use the test light or noid light. Hook test light to 12volt postive and test the negative pin on the injector. While turn the cas by hand....u should see the test light flash. (Can do the same test with cas plugged in and bolted down on engine, just crank the engine over)

Were testing to see if the injector is getting its ground from the computer.


Cas send signal to ecu on engine postion while turning...computer takes that signal...knows when to fire each injector and then grounds out that circuit and the fuel injector fires.

So u have fuel pressure, so were now focused on fuel spraying into the cylinder.

Looking at a -

faulty cas(not likely cause u have spark)

Ecu (again not likely very random to have 6 bad injector drivers bad)

Wiring issue


But lets do the tests stated abouve first.

Oh ok cool will definitely update
Would it be a wiring issue through the wiring specialties harness? It is brand new freshly made.

I was also told i could have the lines swapped on the chassis end so ill probably pull em to see which one sprays fuel when i prime the pump just to confirm completely.

No need to check that u got 40psi...ur good on the fuel lines

Okay, and it couldnt be the fuel quality either?

Well lets make sure the injectors are acually putting the gas in the cylinder.



It could be gas quality.

Fingers crossed then, im pretty sure there in the right ones since they are numbered on the harness i cant remember while im away but thats a easy check. Cyl 1 is furthest to the front right

Cylinder #1 is the injector towards the front of the engine

Like this

Firewall
6
5
4
3
2
1
Radiator

So i got out of work extremely late and still went to test the injectors with a test light but i didnt do that second test ill have to wait till wednsday night or Thursday due to me being out of town. However

Hooked the test light up to 12v from the battery (keep in mind this is a incandescent bulb test light not a led). Touching the light to the ground side caused the test light to light up in the on position same for the power wire. Touching the ground while cranking caused the test light not to shine at all and that was for both sides (power and ground)

Also the injectors are in the right order

Injector should have.... 1 wire(+constant) key on/cranking/running(this is power feed wire, from a relay)
1 wire(-pulsing) cranking/running(this is grounding wire from ecu)

Test the injector connector for these with it unplugged from the injector

Yea the white wire on them seems to be the 12v constant ill have to check the black one again when i return and update.

You can tell ive never done something this involved on a car lol. But is it possible to pull the injector leave it connected and see if it clicks or something? Similar to visually confirming spark. I kno i can do that if i pull the whole rail but with the stock plenem and everything kinda wanna avoid it.

Yea, no need to pull the rail these test will confirm all we need to know. Were heading in the eight direction with this. U have fuel pressure, so we know fuel is flowing theu the rail. Now were working on getn the injectors to open so fuel can spray out.

Check those wires and will go from there

Probably worth mentioning all you're doing is unplugging the harness's injector plug on cylinder 1 and measuring the voltage from those pins

Leave the injectors themselves in the rail and on the car

Also, incandescent bulbs aren't the best as test lights - i used one to measure VCT and thought it wouldn't light up. Grab a proper test light from an auto parts store, they cost peanuts

Hes using an incandescent bulb test light...not just a bulb with wires

What hes using will work fine for these tests

Just tested key on
White wire 12v
Black wire 12v
Both at the unplugged connector
Is something powered that should be grounded?

White white should have 12v key on

Black should have pulsing ground while cranking/running


Is this the same reault for all 6 injector connectors?

Its the same for 1 and 2

This is a brand new harness?

Weird.... either the computers bad or u have all injector wires shorted to power.

Power flow goes

Power(+) relay---injector---computer(-)

Thats it

Printed ecu pinout gonna test injector grounds. It a brand new harnes from them so if thats it imma be pissed i waited forever for this thing

Yea i def check the grounds.....id find it very odd that all 6 injectors ground wires are shorted though

Checked all ecu pins and they have ground so im completely confused ground at the ecu power at the injectors all thats in between is wiring from the harness nothing left to test. I emailed wiring specialties imma see what they say. Garenteed to not be in the show now

Check continuity between the injector ground pin and its corresponding pin at the ecu.

-12v on all im thinking they are all opened somewhere ground side so power just skips the injectors and goes to the open

There suppose to me open circuit till the ecu grounds it.

With engine crankn, are u getting ground pulse at the ecu for injector #1

Pin 107 108 116 shows grounds for injectors

Check for with ley on and whike cranking

https://www.google.com/search?q=rb20...wqHeD4b7tugtvM

Yea when i checked for ground they had it at key on didnt check while cranking tho

i may have tested continuity wrong imma go back and retest. also my friend waited till after i disconnected the ecu to tell me i had to disconnect the battery first. that being said im not sure but i think i may have put it in limp mode off that no way to be sure tho since car doesnt run.

conversation with wiring specialties ended like this so far:


"So power stays - at 10 ish volts is low...
I dont know how you are testing injector signal wires to see ground on it. You are either in the wrong pin or something is still plugged in.
You need to unplug the ecu and the injector to do the continuity test...
Send me a pic of the ecu connector from wire side and i can confirm if the injector wires are in the correct position.

Aside form that you should try another ecu."

i dont have another ecu btw

Yea, no offense but from convo on here i "think" u might be a little confused.
Ill send u a pm will go from there

Update for anyone reading
Known problem: injectiors not firing. All 6
-Test light testing showed power to both wires at all injectors key on
-connecting the test light across both wires and cranking did not cause it to flicker on and off with pulses from the ecu
-eccs relay os fine and sends power to the injectors common wire

The ground side of the injector circuit goes from the injector to the ecu, thats it so there is either something wrong with the harness, the ecu or your ground setup

I have a brand new wiring specialties harness so that is pretty unlikely. So i swapped the ecu. Same problem power to both sides of the injector and no firing. Now im going to recheck grounds at the ecu with a test light.

Are you able to de-pin the plugs and see if it’s the same?

The pins might be arcing inside the plug

On all 6? I doubt it. Injector 2 was easy to do and check real quick but nothing different

Update:
Checked for grounds with ecu connected and not connected, everything appears fine. When the ecu isnt connected i dont have power to both sides of the injector only the black wires on them which i assume is the common. This is for both ecus.

However testing the common power feed to injectors with a test light hooked to battery 12v (Pin 109) it lights up :picardfp:
So naturally i go to the eccs relay since the system goes
B+ > eccs relay > ecu > injectors > grounded by pulsed ecu

Try to test the relay for clicking i dont think it was so i just pulled it out and swapped it with a known good one, no click.
Test the terminals 2 have power (white and red wire as well as a green wire) only one wire has ground being the white and black wire while the solid black wire has neither.

Pull out the relay and test the same pin (still has ground)
Bridge the load side of the relay (still has ground)
At this point im pulling grounds to find where its coming from.
Fuse box was relocated to arm rest so those were the first 2 grounds i pulled. Tested (still has ground)
Pulled the two body grounds in both footwells under the dash (still has ground)
Pulled the rb20 motor grounds by the ect (still has ground)
Pulled the motor ground cable all togethers (still has ground)

Side not my motor has a negative battery cable connected to a mount it doesnt ground to the chassis. Tested this ground and it works

Pulled the battery negative cable to chassis ground (still has ground)
Disconnected the negative terminal all together (no longer has ground. Probably would of sold the car if it did.

so I will be using today to try and find whatever relay or switch is giving ground to the common 12 volt Plus wire feeding power to the injectors

solved
 

Final update problem solved blown 25 amp yellow fuse in engine bay fuse box im not sure what this fuse is connected to wiring diagrams dont really show it or im just blind. car started right up. runs like poop (bad maf - dirty IAC) but it run. gonna make a dedicated youtube video on this problem since every form i went to was a dead end.

Good on you for posting up the resolution

Any chance of taking a photo of the offending fuses location in the fusebox?

ill take one later today!

It is the yellowish fuse that is in the center row of the engine bay fuse box. between the relays and the large fuses. you should have like 2 or three green ones and then the yellow one would be the last one in that line before it goes to the smaller non Nissan specific fuses

Here for any others that have this problem i have made a video compiling all research i did

https://youtu.be/Z7H9NsfP8sA

Hows the car running? Everything good now?

Cars running decent now under 5k rpm
fixed all vacc leaks
fixed the maf

idles strong revs strong sounds cool lol

it wont go past 5k rpm but i think that its because i need to upgrade the fuel pump, still rocking the OEM KA24 pump and it just feels like it simply cant keep up at that demand level. its not like its a regulated cut out you can tell it wants to rev past that point its just limited. but i planned on getting a 255 anyway

im actually gonna attempt first drive today i have to tighten the clutch slave lines with teflon tape (they spray all the fluid out under pressure) and i have to tighten one AN fitting on the chase bays power steering kit i installed the other day, it also sprays fluid on the high pressure line when turning. fingers crossed that thats it then i can start cleaning up the exterior.

Good shit..congrats, def throw a pump in there dont wanna lean it out.

Glad u got everything resolved

only sad thing about it is winter is knocking on our door and im just now able to drive it :naw: