Formulized94

iTrader: (68)

What should i look for when the 5.3 starts and runs for a second, then dies with or without thottle? I know i should look for vats in the pcm, but i am using a truck pcm, that supposedly does not have vats

jimmyp

iTrader: (1)

i think it still has vats

ls1_chevelle

iTrader: (9)

Its the security doing this... My buddy and I had the same problem last night with his 01 computer on a 03 motor...

The procedure we did to "re learn" was turn the key to on(so the fuel pump primes) leave it for 10 minutes, turn the ignition off and pull the key out for 15 seconds then repeat 3 times.

That got us running last night! Thank god too.

-Matt

Formulized94

iTrader: (68)

did that bypass the security? i have never heard of that. please post details of your swap.

ls1_chevelle

iTrader: (9)

What it did, from my limited knowledge about it is... It learns the Ohm's of the key to the computer, then learns the ECU to everything else...

The vehicle was a 2001 1500HD with a 6.0l. Some drunk fool stole the truck, bagged it, over heated it.... My buddy bought it back from insurence so we put a new motor in(old one was low on compression from overheating). His gauge cluster was flashing security and when we started it, it'd run for a second until security kicked in and shut the truck off. Oh, the ecu had to relearn the crap in the steering column(because we had to put a new one in)

Try the procedure I mentioned above, it should fix your problem.

Long story short, Jim is right... Theres still some kind of security stuck in your ecu.

-Matt

Formulized94

iTrader: (68)

ok, so you put it back into a new truck. I am putting mine in an 81 c10 with a modified truck harness. LIke you said tho, I still think there is some security holding me from running. Dang it if i only had hptuners

ls1_chevelle

iTrader: (9)

Just do the procedure we did to get ours to work... If it doesn't work, its 30.45 minutes of your life.

It could quite possible work

-Matt

ls1canuck

I was told by the guy who programmed my computer that there is virtually nothing for the computer to "learn" in a conversion swap. All of the stuff that the computer will "learn" in a factory application is either turned off, or is part of the BCM that you don't have in a conversion.

70 LS1

iTrader: (1)

The body control module sends the signal to the PCM for VATS. That's why the guy had to reteach the computer (BCM).

I had the same problem when I first started mine and it was indeed VATS. I am not that familiar with the truck newer truck PCM's, but all LSx engines have an anti-theft feature that needs to be satisfied in some way or another.

What year is your PCM, was it reprogrammed and what did you do for a wiring harness?

tooblue

I used a 2002 LQ4 and PCM in my conversion 95 Caprice that had Vats. But the Vats signal provided on a 1995 is not able to provide correct signal to the PCM. The signal is not the same as the one provided by the BCM to the PCM from the 2002 donar vehicle. The only way around the Vats is to have it programmed off. This was the information that was provided to me anyway through several sources. Though I did try the existing Vats signal from my 95 and it did not work.. I just wanted to confirm,,Hope it helps.. Roger

G-Body

iTrader: (4)

All the LSx series motors have VATS. If you did not delete it in the computer that is the problem. The truck motors must have the VATS DELETED, there is no way to bypass it since it is a serial data signal.

ls1_chevelle

iTrader: (9)

The BCM must have been the problem then.... I was searchin around the board here and I've come across a few threads where guys have just soldered the 2 VATS wires together. Mind you.... I'd rather just delete it off the ecu.

-Matt

Formulized94

iTrader: (68)

guys thanks for all the help. It turned out that the problem was vats and the ve tables were waaaaayyyy off. So with the vats off, it was too lean to keep running. Anyhow Scott from Intune Motorsports got it taken care of for me. Even though all the injectors still arent hitting. So that is the next feat.