Quote Originally Posted by Dlxman View Post
I have posted this under Unhappy CJ7, but would like to re-iterate my help needed. History - 70s 350 with TBI installed in 2014. .195 intake heads, 30 over pistons, mainly stock, but whole assembly balanced with TH400. Ran great, but now lacking power under acceleration. I got the Tunerpro so I can read more than a key turn for the OBDI. I attached a log file. Idled, went down the road with mild accelerations, WOT a couple times to feel/show the stutter. Idled at a turn, geared down and WOT through 1-3. Once home, I put it in park, and idle went through the roof!
if it ran good before and now doesn't it's time to go back to the basics, fuel delivery & spark. spark plugs, cap & rotor look good? what's your fuel pressure? have you verified your base timing? not saying scanning won't help but there are basics you should check especially if you haven't touched anything since you got it running 8 years ago.

on the note of "rebuilding the tbi". i don't like this term as it usually entails replacing a few orings and cleaning the unit. hardly a rebuild. did you check the throttle shaft for play? i haven't seen one in the last 10 years that couldn't use throttle shaft bushings. i recently am a BIG fan of taking the injectors to a professional shop that has an injector cleaner (ultrasonic) & test machine . getting a flow report is an excellent bonus as well. i don't guess at this stuff any more this is my recipe for a "rebuilt" TBI