For some reason which i haven't figured out yet when i am driving on the interstate and let off the accelerator to coast i noticed that in 5th gear when the car gets down to around 65 mph it starts to get herky jerky and bucks like a bronco and i noticed that if i am not on the accelerator in like 4th gear and let off it bucks when it gets to like 55 mph if i push the clutch in, it always stops jerking. Not sure whats causing it , it also seems to want to idle high (IAC is fine) sometimes around 1400 rpm's(unless i tap my foot on the accelerator, then it'll drop). Any idea's ? I know before i put the tuned port on , when i had the stock 305 TBI intake and Throttle body it didn't use to do that. I am wondering if it is because i am using the original chip which came out of an automatic which was probably programed for a torque converter that's causing this, cause i noticed also when i am cruising in 5th gear the shift light keeps telling me to shift into 6th......problem is i have no 6th gear.... Any suggestions?

 

do a search on TPS voltage, check it.

Program a chip with the TCC turned off, lower the IAC counts a little, and do a search on 'surge', 'rough idle' ect. Lots of info out there for this exact problem, but you will need to reprogram your chip if you want that manual to act right

 

Thanks for the ideas steve...i'll search those out.... TPS is good though...... Reads .57 and 4.8 WOT .

 

most likely same stuff I'm having problems with i would guess.

Kat (another board member) did a swap and she started with a AXXD (vette) .bin then swapped over some of the spark, ect tables over, she said she had a good experience. I unforunatly havnt taken the time to try it yet, but you should do a search on her and read that post, it might even still be on the first page here......

basically from what I gather, the spark, fuel, ect is different now that we are going into a clutch and not a TC, and thats what causes our cars to run funny, plus the extra IAC counts are there to keep the car from stalling with the auto in case the TC doesnt unlock (or something). I lowered my IAC steps down like 1/4 of what they were, with exception of some of the colder start temps for my area and it helped a ton. The reason I didnt make such a drastic reduction in a typical start temp for my vehicle was it would fire, then stall if it didnt have enough IAC time. Good luck, and if you figure stuff out let me know, I'd love to see some working .bins for a stock l98 with a t5 others have created.