okay guys i need help. got the 383 together and running but it surges like crazy when its at idle. especially after its warmed up. its been tunned to a 750rpm but when ever it tries to get there it has to rev back up before it dies. eventually it kills over. Also it has a really bad buckin problem driving around at low rpms. almost like your hitting a wall every time it bucks. and its a cc305 cam in this stroker so i should have no surge at all.
heres what we have checked
Checked wires
Checked for vacuum leaks with a fuel spray
cleaned maf
checked spark pattern
new plugs
checked injector patteren and %duty cycle
checked header primaries for heat, all seem close, 150-200 after being shut off after idle.
readjusted valve lash
if i pull a couple vacuum hoses off the intake it speeds the idle up and it idles fine but the low rpm bucking is still there. what do you think? we are wondering about the tune having problems it was madz28.com
thanks in advance

 

Also when we had the motis scanner on it when driving it we didnt pick up any codes, and injector readings look normal. but one fishy thing is that we picked up some crazy codes about an automatic transmission. here they are we cleared them several times and they came back three times. right now they are off.
codes are
Transmission overheat
solenoid A
solenoid B
and something about torque converter,
i have a manual transmission! is the program causing all my issues?

 

Idle it up with the throttle blade screw.

 

If there was a mistake and you got a A4 tune the IAC tables can be wrong and cause drivability issues like what you are getting. If an aftermarket TB have you drilled an IAC bypass? I know some guys like to instead open up the blades a little but drilling or enlarging the IAC bypass hole will result in a smoother idle.

 

so i can adjust the idle even though, madz28 said my car should idle fine with it being a 383 and a very mild cam at 750rpm. but what about the bucking? since when a couple small vacuum hoses were pulled off the car idled fine i thought id see if that removed the bucking when i drove it but it made it probably about twice as bad. i assume thats because of the unmetered air coming in is compounding the problem. at a low rpm with those 2 little vacuum hoses off at low rpm it was buckin so bad it felt like i was driving over railroad tracks 2 feet high! anymore ideas?

 

im kinda hoping maybe pcmforless will comment on if these IAC tables might be my problem. madZ seems like a nice guy and wants to help me get it fixed right, but im a little irritated because this is my only car and really cant afford to have the computer pulled out again to send in.

 

anymore ideas? im wondering about putting a LT1 pcm in mine but its from a 93 auto. would this allow me to find out if its my pcm doing this?

 

What about the TB? rebored or aftermarket? If aftermarket does it have a IAC bypass drilled? You can try cracking the blades a little and if that helps it will point you in the right direction. My experiance is just that opening up the IAC bypass results in a better idle than opening the blades a hair.

 

o sry forgot to specify its just the stock TB. i will adjust the idle and im pretty sure that will fix the idle surge. but the low rpm 1000-2300 horrible bucking i know is something else and i think thats what is not alowing me to idle down lower. Also the power isnt what it should be. like i said i dont think i should have to adjust my idle to prevent surging since my cam is so small. somethings not adding up here and im trying to pinpoint it rather than get around it. thanks for the help though keep em coming.

 

I was thinking that the ECU thinks its a A4 as well.... hmmm

 

If it was an automatic tune then I think it should lock you out of reverse.

Is the car in Lawrence? If you need a hand with it Im in Manhattan and could offer up some advice... just let me know.

Something else to check if you want quick answers is vacuum. See what its pulling at idle.. once you get it idling. A MAP reading is all thats needed but if get the actual vacuum that would be best.

 

yeah its in lawrence right now. if i cant figure this crap out i might take you up on that offer. so ill hook it up on the scanner and see if i can figure out something on that vacuum part. im kinda wondering about maybe intake not seating right on the heads? deck and heads both surfaced, but the intake seemed to seat fine when we set it on. i sprayed carb cleaner/starter fluid all over the intake tract and vacuum lines tryin to see if would speed up the idle but nothing.

 

Wait to see if its using oil and that will let you know if the intake didnt seat right.

 

ill pull a plug tomorrow and see if it looks like its been burning oil, and im also going to check a block off plate tomorrow that i made for the air delete on the back of the intake. somehow maybe that didnt seal right. i know a vaccum leak would cause the idle problems but would it also do the bucking really bad effect. im thinking so.

 

Its hard to say but something is up if you are getting cam surge with your setup.