R33 weird issue

[Dano.Mano]

For some reason my car will only run on the front 3 cyl.

have changed out coils, today connected it to picoscope.

did injectors test, and coil tests. Each corresponding injector / coil functions properly in the test. 
It started after I reshethed the loom.

with ecu on bench and nothing plugged in, aux 2 and 3 show error state.

when I’m car they show error but still work. When cranking and barely running aux 5 also shows error state. 
 

I’m out of ideas.

[Adamw]

So is it the injectors or spark that is not present on the cylinders that arent working?  Attach a log and your tune.

[danamaniac]

Its very strange, runs like crap. have checked mechanical timing and ignition timing, both perfect.

Injector 1-6 tests show each injector pulsing.

coil 1-6 test show spark.

have tried a different link ecu

One time the engine cont fuse blew when tried to start.

prior to me sheathing the loom with dr25 was running fine.

Even when ecu is on bench shows error on aux out 2 and 3.

when cranking and running more auxes get an error but still function fine. 

have checked all their wiring and there should be no reason for them going to an error state.

car seems like its only running on 3-4 cyl.

Getting close to lighting the damn thing on fire.

 

Any ideas would be greatly appreciated.

TriggerScopeLog.llgx PC Datalog - 2023-09-8 3;42;33 pm.llgx r33ts.pclx

[Adamw]

Your battery voltage starts off at about 11V at idle but gets lower and lower as you rev it, dropping down to about 10.3V at 2000RPM.  That along with the auxes reporting faults would suggest possibly the main power supply is missing or compromised.  

The MAP is high and very erratic, is it a GTR/ITB's?  Is it really a 4bar MAP sensor? - most G4X's had a 7bar. 

Your lambda is also pegged full rich/0.68 lambda, but the cal table is not set up in your map so Im not sure if that is relevant or not.  

[Dano.Mano]

Ok, I just changed the belts and didn’t tighten alternator belt in that log. With alternator working, it’s no different.

it’s a g4x top board on a g4+ lower board. Issue is not the g4x here as it did the same thing with the g4+ attached.

 

Yes wrong cal table was selected, didn’t have the linear cal table selected. 
 

I’m completely stumped, trigger scope looks good. Individual tests of injectors and coils is all ok. We have compression, spark and fuel. What am I missing. 

[Adamw]

Give us a new log with the bat voltage fixed.  

23 hours ago, Adamw said:

is it a GTR/ITB's? 

 

[danamaniac]

Hi mate throttle is a Bosch motorsport 74mm attached to a genuine greddy intake manifold.

I installed my old g4+ back in the car today as i think its best to use this since it was running nice and i have not yet setup the g4x.

It still its far from how it should be but putting the g4+ back has improved things a bit. The rpm fluctuates and runs like crap but when the idle picks up and slowly drops down for a few seconds it sounds normal.

The intake manifold vacuum i think is too low and fluctuates aswell. its an rb2530 with 8:1 comp pistons.

It has been perfect for 3 years all i did was install some splash plates over the camshafts and sheath the loom. and replace my freddy for a greddy.

 

Have checked timing, even pulled balancer off and checked crank pulley. Timing is exactly as it was prior to this.

Ray Hall and some other smart minds in my area are also puzzled at this issue.

If you can come up with any ideas from this log then please please share them with me.

Also never mind the 7 bar map sensor, im using an external 7 bar so what it says is correct.

This is a bit frustrating. I built the engine myself, aswell as everything else that is involved with modifying a car, it has been great for few years.

THEN i install a few bolt ons and now its broken, spent weeks thinking about this and now its hurting my brain. some outside perspective or ideas to follow would help alot.

 

ll.llg

[Confused]

So, you've had the whole wiring loom disconnected and handled, and now you have poor running issues?

 

I'd be going back over every single connector, and do a continuity test on every single wire in the loom - I bet you'll find a pin or two in a plug somewhere that haven't reseated correctly during reinstallation.

[Dano.Mano]

No haven’t had the loom out, just resheathed from the front of it to where it attaches to firewall. Only took injector and coil connectors off. Have checked so many times. Don’t seem to be any issues with terminals properly seated.

[remski2]

As mentioned .. your AFR is way too rich..   An injector stuck open ?

Tho.. looking at your Cal1 table for Lambda 1 .. it doesnt appear to be configured.

Also check for bent pins on the ECU.

Trig 2 has no signal.. so not sure about that, but it is configured.

 

[danamaniac]

This is wrecking my brain. 

Cyl 5 and 6 not working. Unplug injectors 1 2 and 3, cyl 456 work. Plug 123 back in 5 and 6 stop working.

Injectors have been flow bench twice and working perfect.

Injector tests 1-6 work when doing the tests in ecu. any ideas?

.pclr ll.llg Trigger Scope Log 2023-09-14 3;19;07 pm.llg

[remski2]

Have you checked the harness for shorts ? also how have you checked the ground ?

I am assuming you listening to the injectors fire.. or just listening to the engine ??

I'd get 6 lights/Led's and hook them up to the injector plugs... and test from there to be 100% sure.

This feels like the ECU doesnt have enough power to drive them all.. Have you looked a the board itself to see if there are any burn/overheat marks ?

Also measure the amp draw on each injector while testing them.

[Adamw]

The manifold vacuum still looks very suspicious to me.  The noise frequency appears to match the engine cycle time so that would suggest one cylinder is either not inhaling as much air out of the manifold as the other cylinders, or one cylinder is blowing air back into the manifold.  

Possibly a stuck lifter, lack of valve lash, leaking valve seat, broken valve spring or something along those lines?  I guess a spark at the wrong time could cause a similar effect but I think you would hear a backfire or something if there was combustion while the intake valve was partially open.