First, a little info on what I'm working with:

- GM Performance crate motor (330 HP "HO" with Vortec heads)
- Vortec Holley Stealth Ram (With a GM 90-92 style throttle body)
- Kirban AFPR
- Howell Speed Density TPI harness
- 22 lb injectors
- Stock '7730 ECM
- Long tube headers with a heated o2 sensor


I previously had a stock GM TPI setup with a Vortec base running well with this harness and ECM. In the search for more power, I installed a Holley Stealth Ram this spring.

While I was able to drive the car around this summer, I've been bothered the entire time by an issue where it surges about 50-100 RPMs and wants to stall while idling for an extended period of time when warm.

The car will idle fine when warming up, but once it enters closed loop it has this stalling issue. No real issues when driving around once the car is warmed up.

Also, it seems to be down on power, although that might be a subjective thing as I know the car isn't running 100% correctly.

I've already gone through most of the mechanical checks, such as looking for vacuum leaks, swapping out the O2 sensor for a known working spare, setting and swapping the TPS, IAC (For more known good spares), making sure the CTS was working, checking fuel pressure, etc.

I did notice that the idle smoothed out when the o2 sensor is unplugged, leading me to believe that this might be an indication of the ECM not being "happy" once in closed loop?


I've never actually tried editing a PROM, although I do own an AutoPROM and TunerPro as I've always planned on eventually getting into it.


I've attached a zip file with an .xdl and .csv of my car idling while warm. The file ends with the car stalling out (And setting several codes while stalling).

It would be great if someone wouldn't mind helping me go through these and figure out what the problem(s) might be.

My first thought was to burn a new chip with the only difference being that the car would never enter closed loop, as that will at least allow the car to idle while warm.

Thanks in advance for the help guys! I'm looking forward to finally getting into tuning my own car after talking about it for years.

 

probably needs tuned at idle alittle bit. Try abit more timing and more fuel. I think its maybe going abit lean at idle but I cant open the zip file with internet explorer so i cant see the csv.

Did you watch what the blm's do at idle?

Disconnecting o2 sensor would tell me it runs better in open loop and usually open loop is abit richer, but even if lean, there are no fuel corrections being done by the ecm so its more stable.

 

Hmmm, I'm having trouble opening the zip that I uploaded as well now.

I deleted that original attachment and just reuploaded it. Let me know if you still can't open it. There should be a .csv and the original .xdl file created with TunerPro. I included the .xdl in case someone wanted to see a column that I didn't add to the .csv.

Honestly, I know so little about tuning that I didn't know to look at the BLMs at idle. I'll do that this weekend when I go to look at the car again.

 

I still cant open it. I think its an internet explorer thing

 

I think there's a problem here with attaching zips. I just saved and opened the attached zip on here, and it contained a file without an extension. Add ".zip" to the end of that file, and it's my original zip file which contains the .csv and .xdl files.

Weird.

 

Ninja, which version of TunerPro are you using?

from the cvs file, if im following it right, the ECM is pulling fuel.
in open loop im seeing BLM of 114 and Int at 128.
after its in closed loop, BLM starts to come up as does Int.

strange how its kicking those codes, high and low codes for both the CTS and TPS with MAT showing low.

 

Hi Denn,

I was hoping you'd chime in on this!


I'm using version 5 of TunerPro. Specifically build 5.00.4532.00

Those codes are only being thrown at the very end, right as the car stalls at the end of the log.

 

running the log in TunerPro, there is a strange glitch about 3/4 the way thru it. a lot of readings change for just 1 frame. like MPH jumps from 0 to 32 and then back to 0, injector BPW jumps from 2.xx up to 585.xx then back to normal. it may be something with zipping and unzipping the file or something like that. but it does the same thing at the end too, so there may be something else going on
i had something similar show up in my logs that was caused by the bin switcher. it would do it when i switched from 1 bin to another with the motor running.
if it keeps happening with your car, im sure someone here can figure it out.

check the stall saver settings in Tables.
i like to slowly add/remove spark.
0 spark advance/retard at 0 RPM correction up to 5 degrees at 200 RPM.
next, look at the main spark table. even out the cells where the motor idles at. you can look at the pics to see what im talking about.
the pics with red show the changes.
for me, doing this helped a lot with stabilizing the idle.

so you know, im on a new computer and haven't transferred anything to it from my old computer.
the pics are not from a bin i run, they are from S_AUJP_V4 as you get it from
Moates just to show what im talking about.

im glad you can finally drive it
hopefully it gets lined out and you can take it to the track and give Houlie a little smack down

 

and the last pic

 

Thanks for the tips!

Yup, I just checked and saw that exact same frame you're talking about. Weird...

Any suggestions on a good bin to start with? I'm going to do some searching on here for a good baseline, but I'd love to hear any suggestions.

Oh, and I don't know if I'd be able to beat Houlie even with a good tune. That 383/T56 combo he's running right now is pretty stout!

 

no problem

the stock AUJP should be ok to start with.
or you can get S_AUJP_V4 and start with it.
V4 is a little harder for someone just starting with tuning, but it has more options, which is what makes it harder than the stock bin.
if you do go with V4, IIRC V4 has the vette spark tables, so use the stock AUJP spark tables. don't use copy and paste, manually enter everything because V4 has some things moved around so copy & paste doesn't work on those things.

but Houlie can't drive LOL