Could someone PLEASE email me the 7747 Edelrock BIN for their 350cid TBI-to-MPFI conversion? I cannot access any FTP sites with my firewall.

Thanks in advance. Going to go back 7747 with the MPFI again. I will PROM burn 'til I get rid of the surging/buicking bronco thing...

 

I know this doesnt help, but did you try JP's solution and just pull the plug to the IAC? Wondering if a wandering IAC isnt your problem too... they are tempermental devices and even more so when you cam an engine.

 

Been there, done that. Absolutely no effect whatsoever.

I believe it's a combination of a few things:

1) perhaps sync/vs async fight (work with these ONLY if below changes do not work)

2) MPFI causing ECU fits as it takes less time for PW changes to effect the O2 sensor (prop gains lower, below?)

3) The Rich, Lean and R/L threshold values are too lean for my engine (raising the Millivolt values)

4) EGR effects

5) Prop gain (and multiplier) is too high (will lower both tables, in half?)

I gathered most of this stuff from Grumpy's work in the past.

Thanks. Grumpy, for taking the time to write those papers. I hope you'll help me if I need even more than the above.

Thanks to Astro for the BIN.

 

Hopefully it isn't anything like a bad o2 sensor. Mine just started going out on me and it spit out a lean o2 code and was taking abnormally long to get up to a resonable voltage. It was hitting the 150 BLM limit and making my life a living hell (earlier that day upper rad hose blew off). I'm convinced that the higher hp motors go through o2 sensors faster just because of the volume of air that they pump in and out. This o2 sensor didn't last but a year! I couldn't imagine it lasting any longer if there was no tuning and more miles.
If you don't get the correct bin file let me know. I have a mpfi bin file for a 90 sierra with a zz4 and the edelbrock intake. I don't know how heavy your jeep is or what size injectors you're using, still shouldn't be too far off, nothing a little tweaking can't fix. Let's just say that with only a few (4 burns) I was able to get the truck down to a solid 125-129 BLM and it passed NJ emissions with flying colors, not to mention increased gas milage noticably (enough that they are using it as a daily driver) and no more hesitations. The only problem that I have to fix is a high idle. The truck's IAC is at 60 to 80 at idle and is a solid 800-900 rpm steady. The min idle has never been touched (still had the cover on the screw) and now from the info RBob's given me, I'll have that idle problem solved.

 

It runs fine other than in the "bucking bronco" zone of about 1500 - 1800rpm under light load. Plenty of cross counts otherwise, etc, so I'll assume the O2 is fine.

It's just a "hot" combo's issues that I'll have to work through. Couldn't work on it this weekend, though, because of a last minute family party. Maybe tonight.