Okay I know have everything to burn some eproms. Although I am not ready to start on my camaro just yet. There is another project I would like to try. I have a 91 Chevy K2500 w/350 TBI. Last fall the original engine started smoking a little and I had a low mileage GM Perf. Parts 300hp/350 sitting on the engine stand. The heads are stock GM TBI heads, and pretty much everything else is stock. I have an adjustable fuel pressure regulator, and I have it set so the truck runs great at wide open throttle, but at idle the truck seems to idle rough and load up with fuel a bit. Since I am gonna be using tuner cat this is perfect because the .ecu file is for the computer I have. I already pulled the prom and copied the .bin onto my hard drive. The question I am asking is how do I start, what should I do first??
* increase the idle speed a bit?
* have the IAC open a few more steps?
* decrease the injector pulse at idle & low rpms?

Like I said this is all new to me and I am looking to learn this stuff real good before next spring so tuning my camaro won't be such a pain. Anything else anyone could suggest??

Thanks
Jason
jnjspdshop@aol.com

 

The first step IMHO is to connect your scan tool and see where the BLM and INT are at idle. Adjust the VE table #1 till it idles at 126-128 BLM and INT. Then move to part throttle testing in 3rd or overdrive.

I like to try and hit every cell in VE#1 that I can running a constant speed (ie 1600rpms X 50Kpa etc). If you are accelerating it will make it tough to get a good reading. You'll need some steep hills for the higher KPA areas.

 

You mean "dyno hills".

 

Or some good brakes

 

Its easy to hit the 2400rpm X 90kpa cell and below in overdrive on a long hill. The telephone poles are zinging past really fast at this point and its hard to get steady state readings for any higher rpm at high kpa with out attracting the local law enforcement. That's also besides the fact that piloting a C/K 2500 at sublight speeds can be quite the white knuckle experience.

I'm not sure where I stand on placing false loads on the engine to hit the high areas of the fuel map. If you have a trailer, which is totally feasible with a truck, then ok.

But using the brakes for load or a dyno I'm not sure of. I'd like to hear why or why not this is a good idea.

 

Must be working on a N/A car <g>