5.0 vortec to 5.7 vortec engine swap

[Carder09]

Hey guys im new on this forum My name is Eziekel by the way. I just recently purchased a 1996 silverado truck with a 5.0 305 vortec and it had a bad motor so i replaced it with a 5.7 350 vortec motor and i left the 5.0 computer and after that i fired it up and im getting a misfire code and my truck is shaking bad in low rpms but after i drive it passed 2k rpms it seems to runs decent.. can somebody help me? thanks

 

 

Wow, this topic must have been in the bottom of the barrel, maybe someone will see it or you may need to start your own post, but sounds like it might be the comp. In it, im unsure since you would think that these engines shouldn't be interchangeable computer wise, could be different ratios on how things are ran?

[Kunfusion209]

anybody else?

[Kunfusion209]

i swapped out my computer from the 5.0 to the 5.7 and its still multiple misfire random misfire.. somebody help me =/

[Chase Jewell]

I am having the same code after my swap. p0300. Kunfusion 209 did you ever figure out what the cause was? I have changed out pretty well everyhing.

[Badass69]

Wow talk about a dead oldie here lol. Konfusion209 last was on the forum in June of 2011 when he made these 3 posts so I don't think he is coming back lol.

 

If all was well I would say your distributor is the issue most likely. Did you have it timed with a scan tool known as setting cam retard offset? It is to be no more than +/- 2 degrees and is only viewable via a scanner. If you haven't done that then there is the source of your misfire.