What is needed for injector pulse? Need help!

dunnbeetle

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#1
Hi, been working on my supra for a long time now. Seems like the longer it sits the more issues come along.

This is a 2jz swap but running on 7mgte electronics.

Basically I've traced my issue to the injectors not pulsing.

-there is 12v to the injectors with ignition on.
-fuel pump runs while cranking
- afm wires have continuity to the ecu.
-all cylinders have spark.
-as far as I can tell, all grounds are good.
-cps wires have continuity to the ecu.
-had a 2jzge rotorless dizzy hooked up for a while thinking the cps might be bad but still no injector pulse. Cps is installed now for the moment.
-injector resistor is installed. Also tried a different one.
- have tried 2 ecus, same on both.

I suck at troubleshooting wiring but if someone can point me in the right direction it'd help a ton.

Thanks
 

figgie

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#2
well, the trick is to see if the TCCS is grounding the pairs correctly. You should be able to feel the injectors opening and closing as the signal is sent from the TCCS to the injectors.

A sound stethoscope or your finger on injector works well.
 

dunnbeetle

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#3
Sorry, should have mentioned I have tried noid lights and I know the injectors are not pulsing. They have power when ignition is on, just not getting a grounding signal from the ecu. I need to know exactly where that signal comes from if that makes sense.

Thanks
 

figgie

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#5
Well, it comes from the TCCS.

Are you running stock OEM injectors or high impendence injectors?
Is the fuel injector resistor pack installed?

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=D&P=33

Thhe injector circuit is one of the easiest since it is connected to 12v+ DC and the TCCS grounds them.

If they are not being grounded correctly,

bad connection on the TCCS
Broken connection from injector to TCCS (but highly doubtful as it sounds that NONE of your injectors are opening).

Follow 3p's suggestions but do it quickly. Do not linger with the injector connected to Gnd for a long period of time. You are just wanting to hear if they open and close when grounding. Who knows, you might have fried all 6 injectors.
 

dunnbeetle

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#6
Injectors are rc 550cc low impedance. I've also tried Bosch 1000cc low impedance and had the same results.

Injector resistor is installed. Car is a 88 NA, also tried the injector resistor from a 89+ turbo Car.
 

dunnbeetle

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#7
I've checked wiring from afm and cps and they are 100% making connection to the ecu. Not sure if my afm is bad, but as long as it's hooked up I should still get the injectors to fire I'd think.

I'm getting zero CELS. Cps maybe bad? But I tried the rotorless 2jz distributor and had the same results...unless that is bad too. My multimeter is shot so I need to go get a new one.
 

figgie

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#8
ok hold up,
if the car is a na, that means you are running the NA TCCS which means no resistor pack

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=D&P=4

which also means the car REQUIRES High-Z injectors not low-z.

(sorry I made an assumption you were turbo running a turbo ECU)

hopefully you did not fry the TCCS injector driver channels!
 

dunnbeetle

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#9
Sorry again. My initial thread should have had way more info lol. I've posted specs in the 2jz section but there is nobody really looking in there and this is a 7mgte related issue.

Car has a turbo ecu, yellow harness...and I have 2 other ones laying around also.

I do have a map-ecu spliced in by the ecu...but the connections are all good and the wires from the sensors are getting to the ecu.

The map-ecu has been disconnected to basically put everything back to stock in order to get this thing running.
 

dunnbeetle

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#10
I did have this running on e-85 and 1000cc injectors, with the map-ecu hooked up. The car sat for a while and this is where I am...so something went bad or a rodent chewed a wire...something lol
 

3p141592654

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#11
so you grounded the injector wires and the injectors clicked?

As has been stated before, you have ignition so your CPS is fine. If you have ignition, the ECU will also be firing the injectors. The only possible reason it might not be that I can think of is if the AFM KS signal is not being received.
 

dunnbeetle

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#12
The injectors do click. The KS wire does make it to the ecu via continuity test.

I mean the afm could be bad, but even so...ive seen cars start with the afm unplugged...so this wouldn't cause injectors to not fire would it?
 

dunnbeetle

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#13
Went over the wiring by the ecu again and looked up the mapecu install manual. Realized I had the blue wire for the mapecu just tapped into the KS signal wire...so basically the ecu was getting a signal from the afm and the mapecu...

I fixed it but haven't went any further with it. For some reason I'm doubting that was the issue since I had the mapecu harness unplugged and had the afm plugged in and was still having the issue. My fear now is that maybe it somehow messed up both the ecus when I was trying the use the mapecu to start it.

I tried a afm, igniter, injector resistor, and ecu all from a different car today. All had the same effect, no injector pulse.
 

hvyman

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#16
Sounds like wiring. Like previously stated. If you have spark. Your fuel pump runs. Your injectors will be working.
Fuel pump turns on with air flow through afm as does injectors.

Go over what you did with the ecu wiring.
 

dunnbeetle

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#17
Pretty certain the rest of the wires are hooked up correctly.

All the wires for the mapecu just get tapped into the harness...EXCEPT the afm signal and the o2 signal since I have a lc1 wideband installed.

I've gone through these wires at least 3 times. They are all connected securely and should be fine.

BUT since I'm only human, I should probably check it out one more time...
 

dunnbeetle

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#20
Little quick update...tried a 3rd known good ecu after fixing the KS wire and still no pulse.

Still need to get a multimeter to do some actual tests. Went to the store and they didn't have new leads for my good ideal meter and didn't feel like spending $100 on a new one so I might just pick up a cheaper one in the next few days.

Pretty sure the ecus are fine...just missing a signal from something causing no ground output for the injectors.
 

3p141592654

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#23
I went and looked the ECU code. The injector duration is from a lookup table based only on coolant temperature during cranking (rpm < 300).

At this point, my recommendation would be to post a video of the instrument cluster while you crank the engine. I would like to see what the instruments show, especially the tach.
 

figgie

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#24
I agree with 3p and I will further add.

Are the white-black ground wires from the ECU grounded properly (they are usually attached at the lower intake manifold)

Same with the brown wires (2nd set of ground wiring)

these two sets are the grounding for the EMS which gives flaky issues if they are not connected to a clean ground.
 

dunnbeetle

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#25
Just ordered aem ems v2 so if after installing it and still having issues I'll go through the harness.

Got it used for what I think is a decent price...and eventually would have wanted it anyway. Crossing fingers that unhooking the mapecu wires and plugging in the standalone fixes all my problems(yeah right!).
 

figgie

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#26
Just ordered aem ems v2 so if after installing it and still having issues I'll go through the harness.

Got it used for what I think is a decent price...and eventually would have wanted it anyway. Crossing fingers that unhooking the mapecu wires and plugging in the standalone fixes all my problems(yeah right!).

..but you yourself said that you tried other TCCS and it was the same issue so I am not following your logic. The chances that all the TCCS have he exact same issue with injectors being the TCCS is minimal at best.

Now, Per the TSRM you have three output from the TCCS going to the injectors.
This is not that difficult.

If the injectors see +12vdc then that leaves the TCCS side. There is nothing else on that circuit unless the ground to the TCCS is not grounded correctly (2 x white-black cables and 1 x Brown cable).
 

dunnbeetle

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#27
Oh I know...but for $750 I just couldn't pass it up.

Gunna recheck all the wiring down there when I go to hook it up.

Thanks