Only 1 coil firing. No Injector Pulse

[aheroicrevolt]

***issue fixed, bad wiring in fuse box area. Just got lucky wiggling things around****

**New, Fuel Cut issue. Pg 2**
I have a 7mgte that only 1 coil is firing. if looking at the engine, the passenger and center coil are not making spark. I replaced the entire coil pack assembly and mounting plate, still have the same issue. Also replaced the ignitor. no change.

On top of that, i have fuel at the rail with proper pressure. However the injectors are not pulsing/spraying. I assume that means they are not receiving ground. What could this issue be?

 

[Nick M]

If you really have spark on cylinders 1 and 6, but no place else, and you don't have a wiring problem, then your PCM or igniter does not work right. Ignition data is sent by the PCM and it has just two wires, on and off. Data A is off, and Data B is on fires cylinder 1 and 6. That isn't in the repair manual because the last check if nothing else is proven wrong is test with a known good unit. I can't really see it being wiring from the computer, since that would disable the other combinations as well.

I wonder if this is in the TCCS disassembly thread.

 

[aheroicrevolt]

It has a new wiring harness in it from Ron Saunders. So I want to believe it is not wiring. However, wires did pull out of the Ignitor connector when I disconnected the old one. I trusted the shop I brought it to to repin the connector. So I want to assume they did that right as well....
Could it be a ground issue? What connectors should I double check are tight?
What about the injectors not spraying?

I think I will tell the shop to start at the ECU and work down the coil circuits. Do they just test those A and B wires you were talking about? I'm trying to get an understanding for what they SHOULD be doing

 

[aheroicrevolt]

The shop did not want to get into it. My car still sits with no spark and no injector pulse.
I verified wiring at the CPS is correct. I verified the ohms on each coil are correct.
How do I check if the CPS is sending the signals it needs to?

 

[Nick M]

If you have code 12, the PCM is not getting the pickup.

 

[hvyman]

There should be 4 ground wires on the I take manifold. 2 white and 2 brown.

 

[aheroicrevolt]

I reattached grounds, no spark at all. I was incorrect when I said there was spark on 1. No spark at all, and no fuel.
This could be a problem of IGt signal not reaching ECU, because if this signal is not received by ECU, it shuts injectors down.
How do I test if ECu is receiving igt signal from cps?

 

[aheroicrevolt]

If the transmission ground from bellhousing to body is gone, that couldn't cause all this could it?

 

[Dan_Gyoba]

The bellhousing ground shouldn't be vital, provided that the main block ground is in place and good. Basically, if the engine cranks, that means that the block is grounded, since there must be enough current capacity for the starter to operate.

I'd start with diagnosing the IG section of the TSRM. Specifically, check the CPS as per IG-16 if the pickup coils check out okay at the CPS, then you can plug the CPS back in, and check them at the ECU. There's a diagram of the '90+ ECU on page FI-50 There's a diagram that I found (for a MAF-T install) of the '87-'88 ECU Here. You're looking for pins G(-), G1, G2, and Ne. These are the same as the 4 pins on the CPS itself.

if the pickup coils are all within spec, and the wiring to the ECU wiring harness is okay, then you should be getting CPS signal to the ECU. If not, well, then you know where to start fixing stuff.

Next, I would do basically the same thing with the igniter. Page IG-15 shows testing the igniter, then check connection to the ECU for the correct pins.

I'm reasonably sure that you'll get your answer by the time you're done here. Of course there's the possibility that it's a bad ECU, CPS or igniter, but at least you will have done some checks on the CPS and igniter.

 

[Nick M]

This could be a problem of IGt signal not reaching ECU, because if this signal is not received by ECU, it shuts injectors down.

Minor point, but the ECU doesn't receive that signal. It receives spark confirmation, IGF

How do I test if ECu is receiving igt signal from cps?

The fast way is to check for the DTC 12.

 

[aheroicrevolt]

Okay, so I traced it down to a fidgety wire under the fuse box. Not sure which one it is but if I jiggle the fuse box harness around, she fires up. Onto the next things.
Here are my mods:
Cold start delete
EGR delete
3inch downpipe
3 inch exhaust
No Cats
Holset HX40 t4 twin scroll turbo.
EBay exhaust manifold
550 injectors
What I believe is Lexus AFM
AFPR
APexi SAFC2
stock 7mgte manifold converted to a FFIM
Big fricken Throttle body
Manual boost controller
36mm wastegate @8lbs

So the problem is all this was installed at once curing my rebuild. I have the SAFC throttle set at 30 low, and 70 high. Karman, 6 cyl and arrow facing up right.
When I start the car it idles fine at 750 but instantly runs pig rich. 9.6:1 on my Wideband. Should I adjust the fuel map settings on high or low at this point? I can say if I adjust percentages on the high graph I have to get to -20% before the waistband gauge will start gettinge into 12.5:1. So maybe low?
As soon as I open my throttle and it hits 1400rpms, I'm hitting fuel cut and it will die, then catch itself down around 600 rpms.
So at 1400, I'm not even Into boost yet. Is it something with the SAFC settings?