LS1 Starts and 3 seconds later kills power to injectors?

[68rsss]

I changed direction on my build 3 weeks ago and went with a totally different car so sorry for not posting the build. It will come shortly.

I have a 98 Transam LS1 and a 68 camaro. The motor starts and runs for 3-5 sec then power to the injectors is disabled from the pcm. Any ideas?

fuelinjectionconnection.com in Colorado did the harness and I did nothing to reprogram the stock 98 pcm.

Please help!! Thanks in advance

[70bird]

Are you using a V.A.T.S module to bypass the ECM's security system?
This could be malfunctioning or possibly wired incorrectly. You do need to use this module or have the VATS deleted from the ECM.

Another thing to check is the power supply to the engine harness.
I'm using a Painless harness, and there are basically 2 power supply wires. One receives power when the ignition is in the "start" position, the other is powered when the ignition switch is in the run position.
Check to see that you have power to these and they are wired correctly. Also check to see that you have good grounds.

Seems to me that either of these potential problems would not let the engine run for 3-5 seconds though.
That's about all that comes to mind right now
Good luck!

[victionone]

I was thinking it might be the VATS also, but it shouldn't run for 3-5 seconds.

[matty b]

Its definitely the VATS, it has to be removed in programming. Did you have the PCM reprogrammed or did you just get it and hook it up? If you havent got it programmed PM me and I can help you out

[68rsss]

Its definitely the VATS, it has to be removed in programming. Did you have the PCM reprogrammed or did you just get it and hook it up? If you havent got it programmed PM me and I can help you out

I was told by fuel injection connection the 98 pcm didnt need to be reprogrammed, so no its stock never been touched.

[matty b]

haha thats totally wrong. All gen3 and up PCMs have VATS programmed into them. You need to have your PCM programmed to remove that. Not to mention your going to have about 15 codes laddered up at all times for all the emissions stuff that isnt there among many other things. I dont know if you also have an automatic in it but with out having the tire and gear size programmed in it wont shift right and if you are using the speedo output from the PCM it will also be wrong. Its not hard to do the basic programming you need however without it youre car isnt going to move. If you need help with it just PM me and Ill let you know what needs to be done

[megaladon6]

one thing to think about (althought the other guys are probably right about the vats) on GM's the PCM energizes the fuel pump for 3-5 seconds when you first turn the key. then then a seperate "loop" in the PCM runs the pump constantly.

[68rsss]

one thing to think about (althought the other guys are probably right about the vats) on GM's the PCM energizes the fuel pump for 3-5 seconds when you first turn the key. then then a seperate "loop" in the PCM runs the pump constantly.

The pump runs when the key is turned on, fuel pressure 55psi, once the car starts and runs for 3-5 sec the car dies and the pump continues to run for 2 sec after the motor stops. From what I can tell by reading posts at hptuners.com its the vats.

Same problem people are are having after installing there converstion and purchacing the software and learning how to use it. 3-5 sec later the injectors stop with VATS enabled.

FYI the C5 PCM have a sensor on the column that was not an option to disable as of 9/07. The HP guys have a fix but apparently you need to ask for it.

I will get the PCM reprogrammed and update everyone but I'm pretty sure this is the problem.

Thanks everyone!!