So I just finished my 2nd LT1 one swap. Its a 95 LT1 in a 92 RS. The problem Im having is that it starts, Runs for two-three seconds then dies. Sometimes if I keep my foot half way down it will stay running but sputter real bad and eventually die. I had VATS tuned out, then even bought the GM bypass module and hooked that up, still same thing.

Fuel pressure is 40+ the whole time, I have unplugged the MAF, IACV, TPS, MAP all seperatly too see if it would run. Same issues.

 

vacuum leak?

 

Double-check everything - how the plugwires are hooked up, plugs themselves, how the injectors are hooked up. Check the rubber elbow between the MAF and throttle body to make sure it has no rips/tears in it. Could be the MAP sensor or map sensor connector if the tabs are broken off the connector. If the map isn't connected good or if it's bad it will sputter. It could be about anything spark, air, or fuel related but really still sounds like VATS.

 

Thanks guys, Good call on the vacuum leak, I found a huge one right by the throttle body. Couldnt see the port becuase it was covered by a coolant hose, thanks alot for the help