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Hello!
I’m in a pickle here, i need this car done and fully broken in, in time for GAT this year. I needed this thing running last week. I’ve been having alot of troubles getting this car running. I first tried to run the motor on the stand unsuccessfully because my ECM type was never set to (Manual) so it wasn’t trusting the P/N safety and wouldn’t pulse the injectors. Then after I dropped the motor into my Nissan my tuner came over to flash the new tune after realizing he forgot to switch the ECM type to manual. And sure thing first attempt to start it, it fires up, and then immediately dies. I assumed it was because my tuner hadn’t yet corrected the injector data for my ls2 injectors, but me and him looked at the data, and even though it’s not correct it’s very similar, only about 2-3lbs off. So it should still run, just not well, so I got back to it to try and get it running, but then it all the sudden wouldn’t start at all. I could still smell the gas, but the thing wouldn’t start. So I replaced the battery because I had been doing lots of wiring and I figured I had just killed it. And then after I pop the new battery in, it starts, and then dies after. So I was like “great now I can play with it and maybe try to keep it alive with some throttle input” but no, I come back to it the next day and it’s the same thing, it won’t start at all. So now I’m here hoping someone with a fresh mind can tell me I made some silly little mistake that is inexpensive and quick to fix (hopefully). Any ideas please let me know. ( tomorrow I’m going to get my big snap on scanner on it to verify the vats has been properly deleted and is not activating, and to also hopefully spot the issue. ) thank you
So I verified that’s the CMP is good and reading well, and that the VATS is no active, and I’ve also confirmed the car stays alive with spray, also looked at my live data and it’s commanding an a/f ratio of 0.3:1 WAY TOO RICH, pulled #1 plug, sure enough it’s soaked. So it’s running way too rich to run. Why is it commanding a rich fuel ratio. Also keep in mind I’m running ls2 injectors which aren’t compatible with my computer but only have a slight difference from the factory injectors of 2lbs, so do you guys think even though the injectors are close, that maybe the ECM just can’t control them the same way? Or should it still run? Just not well.
Flow rate is only part of the injector data. There is also minimum pulse width, voltage offset and dead time (cant remember exactly how stock ecm labels them)
are the injectors legit and known ls2?
What does your temp sensors read? If one is failed/open the ecm will read them as -40 and dump fuel
Flow rate is only part of the injector data. There is also minimum pulse width, voltage offset and dead time (cant remember exactly how stock ecm labels them)
are the injectors legit and known ls2?
What does your temp sensors read? If one is failed/open the ecm will read them as -40 and dump fuel
that’s a good point I should check the injectors to see if if they are genuine, they just came with the intake I bought from some one. Also what temp sensor are you talking about?
I’ll double check them tomorrow after work but I know for a fact the coolant temp is working, and I’m pretty sure I saw the AIT at 80 something, but just to be safe I’ll double check it.
if they are ebay injectors junk them, but if they are genuine they shouldnt make it run that rich, ive test started many setups with defferent injectors on old tunes and they will usually at least fire and idle/run
if they are ebay injectors junk them, but if they are genuine they shouldnt make it run that rich, ive test started many setups with defferent injectors on old tunes and they will usually at least fire and idle/run
they are genuin ls2 injectors, I just swapped them out with truck injectors and now it’s not firing at all, I don’t even think their pulsing.
Post a tune file and data log if you can. Log your MAP sensor and verify it's reading correctly, key on./engine off.
This is the older tune file, I’m not the tuner here, I got a friend tuning for me. He said he couldn’t find out how to swap over the ls2 injector data because the ls2 has a completely different ECM. So now I swapped it with truck injectors that match my ECM and now they aren’t pulsing and I’m not getting anything when I crank it. I think he made some minor changes since that tune. I know he switched the ECM type to Manual and he did something else I can’t remember what. I was having some issues like this when I tried to fire it up on the stand. I couldn’t get the injectors to pulse, but I knew the ECM could pulse them because when I did a cylinder balance test I was able to manually pulse the injectors. But for some reason it wouldn’t pulse them. I figured I needed a manual OS and not just have all the trans stuff turned off and the ECM type to manual. But I’m pretty sure it should still work how it is. I have no idea what the problem is here and I’m getting frustrated because my tuner doesn’t think my injectors are the problem but I think they are. And I’m just getting no where trying to figure this thing out and I needed this car done last week so I could have time to break it in before gat this year. I wish I could just tune this thing my self.
Wish I could help. I've seen problems happen in tunes that were A4 transmission equipped cars, like mine. As soon as you moved the shifter-BEFORE IT EVEN REACHED REVERSE OR DRIVE (and the subsequent increased load on the engine), it stalled. I'm taking my car in to my tuner now, because temps are starting to fall into the upper 30s to lower 40s at night. It isn't stalling all the time, but it has a surge issue that sometimes causes it to stall.....
Last edited by grinder11; Sep 6, 2025 at 05:22 PM.
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Ls starts and dies within 3 seconds, intermediate 
