Help needed :( LS1 won't fire for more than a second!
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Help needed :( LS1 won't fire for more than a second! Hi there. i'm sorry to post this as my first thread but i have made lots of searchs and i did not find anything that can help me in my research so far. Well maybe i did find good informations but i still didnt try everything yet and as i am in Europe it is really hard to find parts for the LS engines out there so i prefer to explain the problem over there and may find a good answer 
So i have got a Nissan 240sx with an LS1 engine. The conversion have been done last year with pretty much every new parts and now i have some kind of problem with it that i can not resolve over there
When i try to fire the car, the engine fires but dies after a second or so.
i have got NO Maf on it and i dont know what is the reason that it did not fire up properly. i've checked the fuel pump and it is ok!
ive checked relays, fuse, and it is ok as well.
the only difference i see is when i try to use a start spray the engine is running for 2 or 3 seconds before dying. !
is there someone that have any idea where i should start to look at ?
thank you guys!
So i have got a Nissan 240sx with an LS1 engine. The conversion have been done last year with pretty much every new parts and now i have some kind of problem with it that i can not resolve over there
When i try to fire the car, the engine fires but dies after a second or so.
i have got NO Maf on it and i dont know what is the reason that it did not fire up properly. i've checked the fuel pump and it is ok!
ive checked relays, fuse, and it is ok as well.
the only difference i see is when i try to use a start spray the engine is running for 2 or 3 seconds before dying. !
is there someone that have any idea where i should start to look at ?
thank you guys!
Teching In
Joined: Dec 2010
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I had same problem with my ls1 c5 combo the vats was turned off but not the column lock .inj would open to prime motor and shut down. Had tony from tuners inc help shut off column lock. Hope this helps
Last edited by siknss71; Oct 20, 2012 at 11:01 PM.
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the strange thing is that when i use a starter spray it fires for 3 seconds and if not it is just one second and it dies
i really dont know what to do
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jdm, welcome to LS1tech! Search will be your best friend around here....usually.
You have a unique situation as your engine is in a different car, The car won't have the VATS wiring the engine's PCM needs.
I'll assume the engine transplant included the proper LS1 PCM. The VATS function is still in it. Somehow, all this time, it's been disabled-certainly by the guy/shop that did the work.
It looks as if whatever was disabling it is has become undone.
Has any work been done to this car? Has the battery been disconnected for an extended period of time?
You have a unique situation as your engine is in a different car, The car won't have the VATS wiring the engine's PCM needs.
I'll assume the engine transplant included the proper LS1 PCM. The VATS function is still in it. Somehow, all this time, it's been disabled-certainly by the guy/shop that did the work.
It looks as if whatever was disabling it is has become undone.
Has any work been done to this car? Has the battery been disconnected for an extended period of time?
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Joined: Oct 2012
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Thanks for your answer Paul.
i've tried to search about it but i can not really find something that helps me so far. i really do not know how to proceed and i was not building that car. I just bought it from someone. Yes, the battery has been disconnected for around a month so maybe it should be my problem.
right now i do not know how can i bypass that problem without seeing it come again.
is there some way to bypass it without using the HPTuners stuff?
i've tried to search about it but i can not really find something that helps me so far. i really do not know how to proceed and i was not building that car. I just bought it from someone. Yes, the battery has been disconnected for around a month so maybe it should be my problem.
right now i do not know how can i bypass that problem without seeing it come again.
is there some way to bypass it without using the HPTuners stuff?
jdm, welcome to LS1tech! Search will be your best friend around here....usually.
You have a unique situation as your engine is in a different car, The car won't have the VATS wiring the engine's PCM needs.
I'll assume the engine transplant included the proper LS1 PCM. The VATS function is still in it. Somehow, all this time, it's been disabled-certainly by the guy/shop that did the work.
It looks as if whatever was disabling it is has become undone.
Has any work been done to this car? Has the battery been disconnected for an extended period of time?
You have a unique situation as your engine is in a different car, The car won't have the VATS wiring the engine's PCM needs.
I'll assume the engine transplant included the proper LS1 PCM. The VATS function is still in it. Somehow, all this time, it's been disabled-certainly by the guy/shop that did the work.
It looks as if whatever was disabling it is has become undone.
Has any work been done to this car? Has the battery been disconnected for an extended period of time?
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Maybe you can backtrack to the people that did the swap, they certainly somehow had the VATS bypassed or tuned out.
Worst case, you could send the PCM to a mail order tune shop like pcmforless.com and have it tuned out. Some money and a week or so to get back.
Worst case, you could send the PCM to a mail order tune shop like pcmforless.com and have it tuned out. Some money and a week or so to get back.
What car did the engine originally come out of? If it came out of a Corvette no must get tuned out.
If it came out of a F-body you could make a VATS bypass, but you would need to go through the wiring, which might be a pain in the but.
If it came out of a F-body you could make a VATS bypass, but you would need to go through the wiring, which might be a pain in the but.
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LS1 come from a camaro i believe!
Teching In
Joined: Feb 2012
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did u find ur answer to ur question im lookin for the same answer i was wondering if u got an answer for the question u had asked about a physical way to do it im thinkin theres gotta be a way so let me know if u got an answer
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Joined: Nov 2011
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From: jacksonville,fl
I'm a little late joining in on ths post.I did my F-body ls1 swap 10 years ago with a harness that was modified for me.(Can't remember who) It included a VATS bypass module in the harness. A shop that modifies harnesses should be able to supply one. Also a shop like TPIS.com can modify your ecm through the mail to remove items.