Nissan Z32 fires up- stalls, wont hold idle

[Danielz32]

Hello all, I do not know if I am posting this to the proper place, sorry about that

Prior to my issue right now, I used to own a JDM 1993 Z32 Twin turbo 300zx that I installed a Link G4+ into with no issues and had it running like a champ. I have some basic knowledge on operating the link tuning software, but still frequently have to look things up to be 100% sure.

The current issue I am facing now is I have installed a Link G4x into a JDM 1996 Z32 twin turbo car, The motor turns over longer than it should then fires up, if I do not give it gas it will immediately die as it drops below 1000rpm. I can keep the motor running by continuously feathering the throttle, while its running it sounds as though it has a very bad misfire, although as I rev it into higher rpm (past 5000rpm) It clears up and revs cleanly, then again to only immediately die as I let it return to idle.

I am using the provided base map for the Z32. I have also installed Nismo yellow top 615cc Injectors and have set the Injector MS to 9MS (my 1993 z32 I had prior had the same injectors and was also set to 9MS with no issues) There are no error codes at all, I have calibrated the TPS, Disabled the MAF and switched to the internal 7Bar MAP then calibrated that as well. I have so far resorted to changing the factory FPR to another spare factory FPR I had, I have bypassed the fuel pump control computer so the fuel pump has a constant 12v so no chance of a faulty old computer having issues, and also installed a new Tome fuel pump. I had hoped it was one of these things causing low fuel pressure but the Issue I am having has not changed at all.

The car was running flawlessly on the stock ECU and complete stock setup, so I know that the timing was set properly. I will try to log a run tomorrow when I have free time again. I have included the current base map here for now,  I am at a loss for the moment and need to reach out here in hopes of solving the issue. 

Thanks all 

-Daniel  

Z32 Oct 5 2022.pclx

[Adamw]

It doesnt look like you have set the base timing so that would be the first thing to do.  Then adjust the master fuel until it runs the best, I would expect it to be more like 15ms for those injectors, but the value is not really important, just adjust it up or down until it runs best.    

[Danielz32]

Adam, Thanks for your reply

For the MS on the injectors, if the Link provided base map came set up for 370cc factory z32 injectors at 15MS, what would you recommend 615cc injectors be set at?

615cc seems to be about a 60 percent increase from 370cc, so I took 60 percent of 15MS and gave me about 9MS

hope I went about that the right way, as mentioned my Z prior had 615cc injectors and was set to 9ms and had perfect AFR with the provided base map

[Danielz32]

As for the timing, I have a timing light gun ordered and on the way. 

I did notice a potential issue just now on the Timing Trigger offset, it is currently set to 0.0 for the G4x base map. 

But on my old G4+ base map, the Trigger offset is set to -86... both files have not been edited in these fields, its how they are when downloaded and opened.

Could that potentially be a issue?

[Adamw]

As per section 1.6.7 of the manual the base timing is one of the things you need to calibrate before starting the engine.  Because the nissan CAS is connected to the camshaft and mounted with slotted holes, the offset is highly variable from engine to engine.  Most commonly it is around -80 to -90 but I have seen large exceptions to that.  

 

9 hours ago, Danielz32 said:

For the MS on the injectors, if the Link provided base map came set up for 370cc factory z32 injectors at 15MS, what would you recommend 615cc injectors be set at?

That would be assuming that the car our base map came from was dead stock.  That was 10 years before my time so I couldnt confirm, but as I say 15-20ms would be the ballpark I would expect for a 500cc cyl with 615cc injector.  

[Danielz32]

Thanks for the response Adam,

sorry about the late response time, I have actually found a forum from April time frame where another z32 Link g4x user had the same issue. 

Turned out that his base tune file was also set to 0.0 for the trigger offset.  This was corrected by setting it to the -80 to -90 range.

I know that checking the timing is a absolute must for proper installation, but a person trying to start their z32 for the first time is a bit in the dark when it comes to the exact trigger offset needed- that is if they can even realize that 0.0 is incorrect, then it would be a guessing game until it ran properly. Unfortunately it seems that the provided base map for the G4X for all z32 300zx guys is missing the trigger offset timing.

The trigger offset was properly set on the link g4 plus model, the older gen link ECU, at -86 trigger offset. This would definitely be a help for new upcoming z32 guys if this was addressed and updated on the provided base tune files. 

Link ECU are a great product, thank you guys for providing one for the Z32!  The car runs better than it ever has.

[Adamw]

The problem is I have seen the Z32 offset anywhere between -90 and +60.  

[Danielz32]

Could factory Nissan CAS units have that much of a timing discrepancy? I know they switched CAS plug designs on newer z32, my 1996 CAS has the new plug design, but still needs the -86 trigger offset my 1993 had with the old plug design.

Ill reach out to other Z32 guys running link and see what they have as well, Once again thank you Adam