is this a VATS issue??
is this a VATS issue?? Hey guys, getting closer to finishing up my ls1 swap.. I bought a t56 equipped ecm from a member who told me vats was deleted.. after I ran the fuel system, finished up my wiring it starts for a second or two but dies, I checked the fuel psi and it is within spec, tested for power to coils AFTER running and it has power, it starts and dies and I could do it all day but it won't run consistently.. Hooked up the obd 2 and found one code for maf sensor circuit voltage high..
do you think it vats related??
do you think it vats related??
Teching In
Joined: Nov 2012
Posts: 48
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would you be able to use any tuning software to see if vats are turned off or do you have to have the same program the computer was tuned with? I got one of these computers that were supposedly already programed so I put it in my truck that already has the swap done and did the same as you describe yours doing so I hooked up ecm I was running before fired right up I realized I got took! good luck.
Yeah i tried my original donor pcm and it does the same only it doesn't throw any codes other then the security code. It came off a auto equipped car , i was told it would be easier to tune if i had a manual Trans pcm found this one in hopes of getting it running but still tuning it after i get the exhaust done.. What baffles me is the maf sensor code turns on as the car starts then dies after resetting the pcm. I do get all sensors reading on my Solus scanner.. I checked the wiring and everything looks good.
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Verdad Gallardo Thanks! glad to assume it's a VATS issue, I had to second guess my stock harness/ fuse box relay center install a few times thinking I messed up 
I want to get it trailered to J&S performance and get the vats tuned out along with a few other things, hoping to get it done and FINALLY drive it!! Kinda sucks one how I bought a pcm assuming it would work for me and still ended up having to trailer it to the shop.. OH well!! Hopefully the MAF sensor code goes away..
I want to get it trailered to J&S performance and get the vats tuned out along with a few other things, hoping to get it done and FINALLY drive it!! Kinda sucks one how I bought a pcm assuming it would work for me and still ended up having to trailer it to the shop.. OH well!! Hopefully the MAF sensor code goes away.. As Old Geezer said, you might want to make sure your ignition switch is hot in "crank" and "run". If you loose power while cranking, it will want to try to start as soon as you let off the key, but generally won't stay running. Might want to run a temporary power wire straight off the battery to eliminate this before trailering the car somewhere only to find out VATS isn't your problem. Just a suggestion that can't hurt to try.
LS1nova71 and Old Geezer may be right, before I even tried to start mine I swapped in a AAW kit which came with the right ignition switch. But again, your symptons sound exactly like mine even with the right switch. But try the hotwire trick first.
As Old Geezer said, you might want to make sure your ignition switch is hot in "crank" and "run". If you loose power while cranking, it will want to try to start as soon as you let off the key, but generally won't stay running. Might want to run a temporary power wire straight off the battery to eliminate this before trailering the car somewhere only to find out VATS isn't your problem. Just a suggestion that can't hurt to try.
it starts when in run position like a normal car, but dies immediately... Well, if that's the case, then it definitely sounds like a VATS problem. And to answer the other post about the fuel pump, yes, it will come on even with VATS.enabled.
Took it to the shop and found the VATS was turned off... The pcm was tuned for speed density, 44lb injectors, head, cam, and intake.. way off then what my stock ls1 required. Shane from J&S performance was great to work with and totally helpful! After trying a different pcm i got it off the trailer and he tuned my pcm to stock 99 specs. We replaced the old plugs, which i should've done beforehand.. once he got it running i drove for a bit and then it died and wouldn't restart.. diagnosed and found the crank position sensor bad.. replaced and man it runs great!!
Glad my wiring was done right!!
The pcm was tuned for speed density, 44lb injectors, head, cam, and intake.. way off then what my stock ls1 required. Shane from J&S performance was great to work with and totally helpful! After trying a different pcm i got it off the trailer and he tuned my pcm to stock 99 specs. We replaced the old plugs, which i should've done beforehand.. once he got it running i drove for a bit and then it died and wouldn't restart.. diagnosed and found the crank position sensor bad.. replaced and man it runs great!! Glad my wiring was done right!! 