tillyvick14

Hello, I recently swapped out the L98 in my 91 Formula for an L31 with the TPI intake adapter plate after my original engine developed a crack in the block. The new engine runs great on the highway but has a persistent idle problem at a stop, in park, or anytime there is not throttle input. A poster in another thread let me know that running the original L98 prom with the L31 Vortec head engine is likely the problem. Can anyone here help me learn where to begin with getting a new prom tuned for the L31 that will hopefully correct this problem? Thank you very much for any help that you might be able to provide.