My First Prom. Any suggestions on idle?
 

Hi Guys,

I finally got my 383 HSR running! :D I'm trying to tune it myself using a BURN2 with TunerPro.
I know very little about tuning so I've spent most of the day searching through the forums, data-logging, and trying things out on the car.

I thought I would start with the idle. Its decent but wants to wander/surge. Originally I had IAC counts of 0... so I reset the IAC using the procedure here, lowered the base idle to around 950rpm, and lowered (using "smooth") the Spark Advance in columns 48-80 @ 1000rpm. Now I'm getting IAC counts but the idle still surges?

Would someone mind taking a look at the attached data log? I've spent hours working on this and am a bit stumped.

Engine info is in my signature.

Thank you to anyone who can offer any advice/suggestions! I really appreciate it!

-Chris

Re: My First Prom. Any suggestions on idle?
 

Need more info...

How did you take this data? Looks like an AutoXray log??

It shows a MAP value and an Air Flow number (which ordinarily I'd associate with a MAF sensor)... what ECM are you running? What mask are you running?

Re: My First Prom. Any suggestions on idle?
 

Sorry I forgot to mention all that... newbie mistake :)

The data was logged using an AutoXray.

The car uses a MAF sensor and the 165 ECU with 6E.xdf.

Re: My First Prom. Any suggestions on idle?
 

Can you log with Tunerpro RT? It'd be a much more thorough log...

Re: My First Prom. Any suggestions on idle?
 

I used to have a cable for my laptop but it didn't work so well. I will see if i can find it tomorrow and try to log again. Thanks!

Re: My First Prom. Any suggestions on idle?
 

I'm still looking for my cable :( For the life of me I can't find it.

Can anyone offer any advice based on the AutoXray data?

Re: My First Prom. Any suggestions on idle?
 

Was this data taken at 160 or 8192 baud rate? This matters as the INT is oscillating, but also need to know at what speed.

Set the BIN to run in open loop and see how the idle is. It may calm right down.

Another item is the injector compensation values. With the short PW's at idle they are important.

RBob.

Re: My First Prom. Any suggestions on idle?
 

Sorry dumb question... how can I tell the baud rate? The AutoXray was plugged directly into the OBD1 port when the data was logged.

Should the INT be static?

Thanks!

Re: My First Prom. Any suggestions on idle?
 

I did some research and I believe it was at 8192

Re: My First Prom. Any suggestions on idle?
 

It has to be 8192 as there are parameters there that aren't in the 160 baud data stream. Although that doesn't help as much as I initially thought, as the packet rate per second is still unknown.

Placing the engine run time counter in the .csv file helps alleviate this.

As for the INT, no, shouldn't be static, but shouldn't be oscillating. My guess is that the proportional gains are too high.

RBob.

Re: My First Prom. Any suggestions on idle?
 

Hi Guys,

I've been reading a lot on here about tuning. But I have a question about tuning idle...

Is it better to start out tuning idle in closed or open loop? I've read where you can increase the closed loop min temp to force the ecu to stay in closed loop... just wasn't sure if which one is better to start with.

Also, I'm a little confused as to which table will allow me to add fuel in Open Loop?

Sorry if these questions are silly... just trying to learn :)

Thanks!

Re: My First Prom. Any suggestions on idle?
 

I usually do the initial tuning in closed loop. This allows the ECM to use the fuel trims (INT & BLM) to correct for maladjusted tables.

> which table will allow me to add fuel in Open Loop?

RBob.

Re: My First Prom. Any suggestions on idle?
 

Thanks RBob!