Well, I've been struggling to find out why my SBC 350 TBI has been running rough at startup and then running very, very rich. It only took me about 11 months to finally figure out that the PROM in my ECM was the wrong one! I bought the ECM off of Ebay which was listed as for a 5.7l sbc 350 with a 7747 which was exactly what I need. Since day 1 of cranking her over, it never ran right. I put new injectors, all new sensors, plugs, took it to mechanics (one mechanic said I needed a new cam, even though my motor had about 500 miles on it after a complete rebuild 
). So after all this I called Howell Fuel Injection and spoke to Troy. Even though I didn't buy any of my TBI stuff from them he walked through my scanner numbers with me. Ended up having a PROM for a 3.4l motor. So I ordered a new PROM, plugged it in tonight, and she fired up and went straight into a smooth idle! I was super stoked. First time it has run smooth and non super rich. Thanks Howell!
Nick
). So after all this I called Howell Fuel Injection and spoke to Troy. Even though I didn't buy any of my TBI stuff from them he walked through my scanner numbers with me. Ended up having a PROM for a 3.4l motor. So I ordered a new PROM, plugged it in tonight, and she fired up and went straight into a smooth idle! I was super stoked. First time it has run smooth and non super rich. Thanks Howell!Nick
Congrats!
