1jz injectors not firing....HELP!!!

[87supraguy]

i did research the forum for related issues... found a couple good threads but they never seem to find a cure and if they do they never report back to the thread stating what the issue was. seems like a very common issue based on the thread search.

anyways... the issue i'm having is i'm getting spark but no fuel!

i checked the return side of the rail and i have a nice powerful flow of fuel going to the rail, i don't hear the injectors firing. i squirt some starting fluid into a vaccumm line that goes straight to the intake manifold and only when i squirt the starting fluid does it actually want to turn on. i am getting only one code and that is code 12 which i believe is no rpm signal....

a little about the motor and the car: 1jz (JZZ30), everything is stock on it, it's in an 87 mk3 hard top, 5spd, non -turbo base model.....

 

[IBoughtASupra]

Check the grounds in the intake mainifold? Are you getting spark?

 

[87supraguy]

Yeah the grounds on the intake mani are on nice and tight. It is getting spark and I know it's just the injectors not shooting fuel into the cylinder. Cause when I shoot. The starting fluid in, it starts and runs till it burns the fluid up.

 

[IBoughtASupra]

Well that means your cam and crank sensors are sending a signal.

Check to see if when your ignition is on, that you have a constant 12V at each injector. If not, have someone crank the engine, check both pins. If you are getting a ground on one pin when cranking then your injectors are not being powered.

When doing this test, you should be getting a pulsating ground on one pin. Your test light should be hooked up to the positive and when you crank the engine the test light should flash as the ground is being sent. If you are using a probe then it should indicate a ground being sent on off on off.

So if you have a pulsating ground at one pin of each injector plug, that means the injectors are not getting power and you should check the relay because each injector should have a constant 12V and are turned on when grounded.

Report back.

 

[Devin LeBlanc]

Noid lights, Check fuel pressure, Check voltage and ground at each injector with a DVOM

 

[IBoughtASupra]

Noid lights won't work here. They need both 12v and ground.

If the ECU is allow spark, it should be allowing fuel by grounding off each injector.

I asked the OP to check to see if that is happening, if each injector is being grounded, which the ECU does, and there is no 12V signal, then it points to that relay powering the injectors when the key is on, since the ECU does not power the injectors, it just sends a ground to complete the circuit, but you want to get technical, electrons do flow from ground to positive, nor positive to ground...

 

[JORAMI17]

i checked the return side of the rail and i have a nice powerful flow of fuel going to the rail

This statemanet sounds like you got pressure going into the return side and not into the feed side of the rail. Are you sure when the swap was done the lines weren inadvertently transposed?

 

[IBoughtASupra]

This statemanet sounds like you got pressure going into the return side and not into the feed side of the rail. Are you sure when the swap was done the lines weren inadvertently transposed?

I believe he is trying to say after the feed since, the fuel flows to the return and there is pressure there meaning the feed side is sending fuel, it flows through the rail and goes to the return side where he probably pulled the line or maybe has a regulator there.

Let's wait and see what he says..

 

[aphxero]

I've had this happen with no igf. But yeah itf they have no power on them that's probably it. But then again this guy is in a forum asking basic questions so ya never know. Hey dude you got a pulse on IGF? If the ecu sees no spark confirmation it'll fire sparks blindly but will shut off the injectors.

Just sayin.

 

[87supraguy]

ok sorry guys for the Lagged and late response.. been busy with work and now school again. so my current finding i checked all injectors and the both have 11.85v going to them... this is probably because my battery is low cause i just hooked the alternator up and was cranking it with out an alternator. either way.... both pins lit up nicely and both read 11.85v all the way across... so next step would be ECU right? cause if the injectors are getting the voltage but the ecu isn't grounding them that might be the issue. the ony thing i'm confused about is i've checked the ecu for any signs or leaking caps and burns ect and even had a buddy in Phoenix test my ecu for me awhile back and it was perfect.

what would be my next step?

 

[IBoughtASupra]

Both pins are getting 12 volts? Ground is only sent when cranking and the 11.xx volts is fine at this point.

Was your car running before? Both pins should not be getting 12 volts, only one wire should be getting 12 volts.

Was the test done while cranking since that is when the ground is sent, if you cranked and checked for ground then check your ECU now with a working one.

Are you running a stock regulator or Aeromotive?

 

[87supraguy]

yes 12v at both pins. no i have not gotten the 1j to start since ever actually... i did have a previous problem before where the car would turn on and after about 3-5 seconds it would shut off... and it kept throwing a code 14 or 13 i think which it has to do with the crank and cam sensors ... i had a bad connector on the rear cam sensor so i bought a spare harness and replaced the connector in and that code went away and now i'm having a new problem and new code, code 12 and no injector impluse i didn't try cranking it because i'm by myself and hard to be under the hood and in the seat. i may have to go buy that tool that you hook up to the starter to jump it. not sure if i can get an ECU cause the guy that tested mine is in another city. but currently the 1jz is bone stock so it is running off the stock fpr

 

[IBoughtASupra]

If you had the ECU tested, then lets assume it is fine right now. You will need to try and get to crank the engine and see if you get a ground at one pin of each injector plug and it should be pulsing.

You can go to Harbor Freight and get a NOID light kit. If it blinks, you are getting pulse, no blink, no pulse. Just position it where you can see it when in the car or if you can stand outside the car and reach to crank it, just set it in a spot where you can see it if you are in or out of the car.

http://www.harborfreight.com/11-piece-noid-light-and-iac-tester-set-97959.html

If you don't want to buy it, just buy it now, do the test, don't break anything and then return it. I like to buy the tools because they make troubleshooting a lot easier and it is always nice to have tool, they make your job easier. I will buy quality stuff, better than harbor freight when I need to like a digital caliper for lash adjustment or a torque wrench, for the NOID lights, it will be fine.


I saw your post on SupraForums saying you tested the crank sensor and it was in SPEC. What about the cam sensors? How are the plugs on those? Check the resistance of them and let us know....

 

[aphxero]

...

 

[87supraguy]

so i went and bought a noid light to test the injector connectors and they are not lighting up. cam sensors are (front sensor) 1.112k ohms (rear sensor) 1.101k ohms... i tried to get the ohms with out the "k" but wasn't able to... any other ideas? btw the connectors are good on them... i just replaced the rear one.

 

[IBoughtASupra]

That is what I was saying. You are not getting any ground to your injectors.

This relates to two different things. Sensors or ECU. You said you had the ECU tested, so we are going to assume it is in working condition.

The sensors that control the spark and fuel see the crank and cam sensors.

You can try and replace the ECU with a known working one to see if the car starts, I don't mean to buy one, but if you have a friend who can lend you one. This would be the easiest since it is easier than changing a bunch of sensors, even though you had it tested....

Here is a link to the specs for each sensor...
http://www.turbosupras.com/pdfs/JZA80%20TSRM/IG%20(2JZ-GTE).pdf

The 1.112k is the same as 1112. According to the specs for the 2JZ, the cam sensors are in spec. What was the reading for the cam sensors?

These sensors can still be in spec but send a wrong signal, similar to the AFM on the 7MGTE. If the crank sensors checks to be good, you will need to try another ECU and if that fails, then replacing the sensors is next. If that fails, then we will need to check the wiring for each sensor to the ECU.

By the way, do you have any codes?

 

[87supraguy]

i'll ask if he can come down and see if i can use his ecu sine he has a jzz30 ecu. i did buy 2 cam sensors just incase a couple days ago and they were pulled off a known running motor so i'll compare the resistance in those and maybe swap them out as well. the only code i'm getting is 12.

 

[IBoughtASupra]

Code 12 is the RPM signal. This thread is worth looking at. It won't take long to pull of the lower cover and check everything is fine with the lower gear.

http://www.supramania.com/forums/showthread.php?81090-1jz-swap-no-spark-cel-code-12

It sounds like the ECU is not getting a signal from the crank sensor, I have seen a 1JZ start and run on one good cam sensor but it didn't run very well but did start. You should check the continuity of the wires from the crank sensor to the ECU.

There is a simple way to do it and if you are interested to do that in the mean time, send me a PM and I will explain and it is fool proof even if you are not good with wiring. Busy right now.

 

[87supraguy]

Code 12 is the RPM signal. This thread is worth looking at. It won't take long to pull of the lower cover and check everything is fine with the lower gear.

http://www.supramania.com/forums/showthread.php?81090-1jz-swap-no-spark-cel-code-12

It sounds like the ECU is not getting a signal from the crank sensor, I have seen a 1JZ start and run on one good cam sensor but it didn't run very well but did start. You should check the continuity of the wires from the crank sensor to the ECU.

There is a simple way to do it and if you are interested to do that in the mean time, send me a PM and I will explain and it is fool proof even if you are not good with wiring. Busy right now.

i did check out this thread before but would that be causing the injectors not to grounded? also sent pm

 

[aphxero]

I'm only gonna say IGF one more time. Check the wire. If the ecu doesnt see the confirmation IGF signal it doesn't turn on the injectors. Seriously check continuity from the igniter to the ecu. If it's good check for a pulse on it. No pulse is probably bad igniter or possibly ecu but I seriously doubt it. I've dealt with this numerous times so I'm speaking from experience here. I'd be surprised if it's anything else.

If crank sensor wasnt functioning you'd get no spark period. period.