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-   -   Rb20 s14 starts then dies STUMPED (#/f/showthread.php?t=670936)

BenRice 10-08-2019 05:38 PM

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?

BenRice 10-08-2019 05:41 PM

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

NoBrakes! 10-08-2019 05:48 PM

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?

S14rebuild 10-08-2019 05:53 PM

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.

S14rebuild 10-08-2019 05:54 PM

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.

NoBrakes! 10-08-2019 06:06 PM

Quote:

Originally Posted by S14rebuild (Post 6359843)
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.

S14rebuild 10-08-2019 06:07 PM

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

NoBrakes! 10-08-2019 06:15 PM

Okay, and it couldnt be the fuel quality either?

S14rebuild 10-08-2019 06:17 PM

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



It could be gas quality.

NoBrakes! 10-08-2019 06:20 PM

Quote:

Originally Posted by BenRice (Post 6359837)
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?

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

S14rebuild 10-08-2019 06:23 PM

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

Like this

Firewall
6
5
4
3
2
1
Radiator

NoBrakes! 10-09-2019 12:42 AM

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)

NoBrakes! 10-09-2019 12:43 AM

Quote:

Originally Posted by S14rebuild (Post 6359851)
Cylinder #1 is the injector towards the front of the engine

Like this

Firewall
6
5
4
3
2
1
Radiator

Also the injectors are in the right order

S14rebuild 10-09-2019 05:06 AM

Quote:

Originally Posted by NoBrakes! (Post 6359870)
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)


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

NoBrakes! 10-09-2019 07:49 AM

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.

S14rebuild 10-09-2019 08:04 AM

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

BenRice 10-09-2019 03:26 PM

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

S14rebuild 10-09-2019 03:55 PM

Quote:

Originally Posted by BenRice (Post 6359931)
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

NoBrakes! 10-10-2019 07:47 AM

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

S14rebuild 10-10-2019 07:50 AM

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?

NoBrakes! 10-10-2019 07:52 AM

Quote:

Originally Posted by S14rebuild (Post 6360002)
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

S14rebuild 10-10-2019 08:04 AM

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

NoBrakes! 10-10-2019 08:08 AM

Quote:

Originally Posted by S14rebuild (Post 6360004)
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

S14rebuild 10-10-2019 08:49 AM

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

NoBrakes! 10-10-2019 09:26 AM

Quote:

Originally Posted by S14rebuild (Post 6360009)
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

S14rebuild 10-10-2019 10:03 AM

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

NoBrakes! 10-10-2019 10:32 AM

Quote:

Originally Posted by S14rebuild (Post 6360022)
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

S14rebuild 10-10-2019 10:36 AM

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

S14rebuild 10-10-2019 10:37 AM

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

S14rebuild 10-10-2019 10:41 AM

Pin 107 108 116 shows grounds for injectors

Check for with ley on and whike cranking

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


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