GVR-4 No Start Issues

[ob1murry]

I have a automatic JDM VR-4 that I just can seem to get to start.

The car was all stock ran fine but sat for about 8 months while I was doing some work on it and getting married and having a kid. Now, I can not seem to get it to start and I am not sure why.

While the car was sitting the following changes were made to the engine:

1990 JDM ECU swapped for a USDM ECU with ECMLink V3
Swapped the 13g for a Evo 3 16g
FP Exhaust Manifold
AFPR
PTE 880 injectors
Boost gauge
Removed the BCS
Rebuilt the throttle body with a FIAV bypass.
New plugs and wires.
New O2 housing and CMP 3 inch turbo back.
New LC-2 installed and wired to the factory narrowband location.

For the ECU, I simply took a look over here and made sure all of my wiring for the 90 JDM wiring for the ECU matched up with the 91+ USDM wiring for the ECU and did not require the pin swap.

I have verified that car has spark and fuel. I did a cold dry compression test and the results were 140 across the board, so it seems unlikely to have jumped timing.

I thought perhaps the fuel delivery was weak so I pulled the rail and replaced the 880s with some 680s I had sitting around just to verify the injectors were not bad, even though they did seem to be spraying correctly. I even pulled a known good PTU and Injector resistor pack off another VR4 for testing, same issues. Replaced the battery since I was seeing a bit low voltage after the car sat for a while, same issues.

I don't see any blown fuses and the MPI seems to be working correctly. I did notice though that when I turn the pump on via link to set the fuel pressure, it will reach and hold steady at 43.5 psi, but during cranking it will not exceed ~36 psi which seems odd to me.

I have ordered a new CTS to install but have not done so yet.

The car will crank and from time to time it stutters like it is on the verge of starting but never does.

I did read and follow the how to diagnose a no start thread, but nothing has been useful in solving my issues yet.

I've attached a quick cranking log that might be helpful, but any help at all would be appreciated because I'm stuck at this point.

 

[Vegas Smith]

1) simulate idle switch from tps
2) Set tps to 0.63 volts
3) unclick disable airflow smoothing with SD
4) Your battery voltage is dropping to like 7v on cranking. Something wrong there
5) You have a fuel pump error code. Something wrong there.

 

[ob1murry]

1) simulate idle switch from tps
2) Set tps to 0.63 volts
3) unclick disable airflow smoothing with SD
4) Your battery voltage is dropping to like 7v on cranking. Something wrong there
5) You have a fuel pump error code. Something wrong there.

1. Done
2. Done
3. Done
4+5. I'm not sure what is causing this. The battery is slightly low due to repeatedly trying to start the car over the last few weeks to try and diagnose the issue so it is sitting on the charger now. However this issue was present even when the battery was brand new off the shelf and reading over 13 volts with the car off. I looked up the fuel pump DTC previously and it indicated that the cause was low voltage at the pump, which is in keeping with the cranking issue. I'm not sure if it is a problem or just a symptom of the low voltage. Regardless, I'm really not sure where to go about checking for this issue. I see no obvious wiring issues and did some testing with the multimeter and found no obvious problems with any of the wiring at the battery. Could it possibly be a bad starter that cranks but is pulling way too much power?

I had also taken the ECU out to inspect and it looks pristine, no sign of any burned traces or leaking caps or anything like that.

I'll wait until the battery is fully charged and get another log to upload.

 

[ob1murry]

Here is a crank log from today. The battery sat on a charger overnight and was showing 100% charge. I even tried starting it a few times with my jump box attached just in case. Still shows insane voltage drop during cranking. I already replaced one battery after the car sat because the problems seemed symptomatic of a bad battery and the same issues continue. I've checked a bunch of the wiring and everything seems ok, any guidance on where to look for wiring issues that would only be occurring during cranking or any other help on how to get this thing started would be greatly appreciated because at this point it is basically just trail and error for me and I feel like I'm spinning in circles.