Hello fellow Gearheads, I've been visiting this great forum for a couple years now and have always been able to get most of my answers by just reading post........up until now. My project is an 87 Jeep YJ with a Chevy Vortec 350. The project started around two years ago with a TBI350 from a late eighty G2500 van. Then last November the motor lost a cylinder so I decided to go with a rebuilt Vortec 350. I figured from all the hours and hours of reading on this forum that I would be able to make the required changes to the fuel/spark tables etc. and have a good running stock Vortec 350. At first things seemed to go well with the stock injectors 61.2# but I always had a slight miss. So while pondering on the reasons for the miss I convinced myself that the old injectors must need cleaning or be replaced so I threw down the cash for some rebuilt 65's. At first all was going well. I used the TBI calculator to set the new BPW and injector bias then data logged to set the VE table. This is when I started having problems that I haven't been able to solve. The main issue is at idle, it switches between sync and async. This is causing a surging idle that I haven't been able to figure out over the past few months. To make a long story short I decided to set the BPW and Injector bias back to stock 135/0.42 (I know 0.42 isn't stock but close to 0.396) and started over today. Things seemed to be going great with two data logs....idle was good and BLM were getting close to 128 after a few adjustments. Then I decided to take a break and came back two hours later and now the problem with the sync/async switching at idle started again. So now I'm bowing down before the TUNING GODS asking for leniency on my retribution for a failed Tune. Seeking any help or direction to a thread discussing this issue. The vitals are has follows:


Fuel pressure at 15psi (verified by gauge)
TunerPro (purchased)
Moates Hardware
350 vortec stock L31 bored 0.030”
Edlebrock performer dual plane intake
TBI/intake adapter is 1/2” thick aluminum (I've verified no vacuum leaks)
Shorty Headers

1987 jeep around 3300lbs
4:56 gears 33” tires
custom Dana 44 front ARB locker
custom Ford 8.8 rear ARB locker
TH350 custom built mated to Early Bronco Dana 20 Transfer Case
Hydro Boost Brake system disc front/rear
High steering with Performance unlimited steering system


Bin:
Started with ADYR $42
Spark table is modeled off Dave W Vortec table listed on this forum
Some changes have been made to the IAC setting to bring down idle a little quicker
Included are two data logs and Bin File
Data logs included are: Last data log for setting VE table and idle log showing the switching between Sync/Async.


One other thing I noticed on this last log was an Error code on the VSS. For some reason this pops up from time to time. I can sometimes disconnect the battery or change the Chip and it goes away. I do utilizes a 2 pulse VSS sensor from JTR. I think I'll check the connection at the position switch to make sure I'm getting a good grounded connection in park position.


Thanks for any suggestions