moderate Z28

Ever since I installed my hotcam in my 93 T/A, it has a mild surge under load. Like when you first take off and when you are coming to a stop. It only surges/bucks under about 1,000 or 1200 RPM's. It has a mail order tune from Madz28 so I dont know if thats the cause.
The IAC is kinda messed up on the car. Sometimes it works, sometimes it doesnt. I have thought it to be one of these
1- It needs a higher stall
2 - It needs a dyno tune
3 - Replace IAC
I have searched and it seems like every thread came to a different conclusion but it seemed most blamed the stock stall.

Regarding the IAC, when you first start the car it will idle at a different RPM every time I start the car unless its warmed up already. Sometimes it will hold an idle when cold, sometimes I have to warm the car up before it will hold an idle, like a carburated engine.

myltwon

iTrader: (1)

sounds like the IAC is the first problem you need to sort out, there is a guide on resetting the IAC you should try out first IMO. then look into cleaning all the passages, next would be replacing it if the problem persists.

stock stall is definately not going to help low rpm driveability but it seems to be a problem beyond that.

moderate Z28

Ive been driving the car for about 2 years like this. Im pretty sure Ive tried resetting the IAC before with no luck.
When I first bought this car about 8 years ago, the IAC was presenting the exact same idling symptoms. I replaced it and it fixed it for about 5 years. Now its not working right again.
What kind of symptoms are usually present? I mean even the hotcam kit calls for atleast a 2500 stall.

pro94lt

Have you hooked it up to a scanner or scanning software?

moderate Z28

NO SES light but if your talking about tuning software, thats above my head.

Badazz 97 TA

iTrader: (18)

yeah i got some surge when comming to a stop or sitting in traffic. Or if i switched from like park to drive while holding the brakes. The 2800 stall fixed that problem. Drives perfect now.

i would definitaly figure out the IAC problem first. You obviously know its a problem so get that sorted out first before you start looking at other parts.

AChotrod

iTrader: (17)

I had to drive my M6 different when I had a hot cam. Once I got used to it it felt normal. So I would say the stall could be the issue.

moderate Z28

So the stall did fix the problem? This is an intersting topic because it seems there are ALOT of mixed opinion on why a cam surges like this.
And BTW, If I power brake the car above the RPM that it surges it will take off perfect. Thats something to think about it.

AChotrod

iTrader: (17)

I had to rev up my car a few RPMs higher to get it to drive good. They dont tell you to get a bigger stall for no reason.

Badazz 97 TA

iTrader: (18)

it helped for me, but i didnt have IAC or electronic issues that you might be having. Having the stall makes it drive so nice. almost like stock but better.

Stocker94z

Get a stall, that will help plus it'll make the car a lot more fun.