Blazin4x4

I got her fired up today... turns out I reversed the #6 and 8 plug wires. Now it runs perty darn good as long as my foot is on the pedal but the second I pull my foot off it dies like I killed the ignition. Blm was 128 for the most part and smelled just about perfect. Needs a little fine tuning though. My setup is on my profile. I've played with the ve tables and no change in idle. Played with the Iac in park position and no change... I'm not sure where to go from here... Seems like it's almost out of fuel when I let off the pedal... either that or too rich to run... I don't know. I'm pretty well stumped.

I haven't taken it out of park because it won't idle yet.

I'm thinking I need to play with the stall saver Iac step decay coeficienct or

DFCO iac. All of my Iac settings are pretty much stock for a 88 350 tbi with a 7747 ecm. The Iac park position is 89... Is that too high? Thanks for any tips

Fast355

iTrader: (2)

Have you adjusted the Minimum Air rate on the TBI. It maybe a case of insufficient air for the engine to stay running. The stock TBI is setup for an engine that pulls 18-22 in/hg of vacuum at idle. When you put one that makes 14-15 in/hg of vacuum or less in there, the throttle blades need to be opened further at idle. I know the Holley is adjustable. I would open them about 3-5 turns of the screw then see how things go. The idle will probably be up around 1,200-1,500 rpm, then start closing down the screw. You will probably find that your engine wants a commanded idle speed of about 750 RPM, about 5-10 IAC counts, and 20* of timing at idle. What does your timing at idle look like, big cams like alot of timing at idle.

Did we ever successfully get you the .BIN that I have from my LT4 cammed 350? I have since found how to attach it in ZIP form.

Fast355

iTrader: (2)

The one I have is the $OD code from the PCM that I was running at the time. It is NOT directly compatible with the 7747s $42, but you can compare what you are doing against what I had done.

https://www.thirdgen.org/forums/atta...lt4-cammed-350

Blazin4x4

No... But that would be real cool. I did get my ve tables right around where they need to be runs good but just won't idle. I did open that screw as far as it will go and nothing... tried it every where else and just won't idle. I think it might be my vacuum hoses hooked up wrong... Also I did hear a whistle tonight... wasn't sure if it was the belts or a leak though.

Iac steps fuel addr is at 40 .... Iac park is at 40 also.

What exactly is the Iac number telling you? Is higher number more air/fuel?

But yeah your bin would be a huge help. I just can't quite figure out what to do to plug it into my 7747 . Wheres my dunce cap? oh yeah, its on my head... Dee dee dee

I clicked on the links and it tries to go the prominator program... How do I read them in tunerpro?

Fast355

iTrader: (2)

IAC count is a number you get when looking at a scan tool or log. The IAC count is the final commanded location of the IAC pintle. It goes from 0-255 counts. 0 = closed, 255 = fully open Most TBI .BINs have a cap at about 150 counts. I generally setup the cap at 255 counts and use alot of throttle follower at speed, this increases the airflow capability of the TBI substantially at speed.

I would revert the IAC settings back to factory for now. You really don't need to mess with them much. If you don't know what to do with the constants to obtain the desired results, the IAC is like "peeing into the wind" when you mess with it. I found this out the hard way after stalling for everytime I stopped for 2 weeks straight as I fought some basic changes I had done.

Just out of curiosity where is your MAP sensor tied in? It almost sounds like you have it on a ported vacuum connection. It should be connected to the vacuum port which sticks out right between the fuel fittings.

I posted the .BIN and the .ECU/.XDF (forget which) above.

To open them in tunerpro right click them, save target as, then open them in Tunerpro. You might need to download TunerProRT as they are setup for RT.

Blazin4x4

I opened the files and I get the prominator program? How can I read them in tunerpro?

Fast355

iTrader: (2)

Open Tunerpro, Open the .ECU, then Open the .BIN. You might have to right click, save target as.

Blazin4x4

Got it... thanks.

I'll probably copy your ve tables and see if that helps...

When you say more throttle follower what do you mean?

I think it may be they got all jumbled up after I had a fire in it.

Do you know Where I could find a vacuum diagram for an 88 tbi 350 blazer?

Blazin4x4

It looks like both are bins because they are both working in tunerpro with my 7747 xdf.

Those ve tables have a lot of peaks in them... I was under the impression the smoother the table is the smoother the motor will run. Do you remember the tables having alot of peaks in them or am I just not putting it into tp right?

Fast355

iTrader: (2)

You HAVE to open it with the $0D selected as the .ECU/.XDF. The addresses for the tables are completely different in the $0D code than the 7747s $42.

Blazin4x4

This is the problem I had with the other bins you gave me. I don't know where to get the codes or how to even use them... I am still VERY green to tuning.