Did The GM IAC Problems Ever Get Truly Solved?

69 1/2 Six Pack Bee · Post by **69 1/2 Six Pack Bee** » Wed Aug 16, 2006 9:22 am

I had many issues with missed steps, not following temp curve, etc,...etc.. as many other her had which some of you might remember by reading my old posts. The post that said the problem was "solved" with the latest version of code showed some success but there were still a select few who had existing troubles.

This summer I put back on the Q'jet & HEI because I wanted to go vacationing without any headaches but I might delve into this project once again. I had since sold all of my MS-I stuff but I might entertain the possibility of building a V.3 and start from the get-go but I really liked the advent of the IAC but only if it is reliable.

Any words of encouragement?
Thanx,
Bud

TurboGt · Post by **TurboGt** » Wed Aug 16, 2006 10:09 am

I have been running the new code and it definately works better. Yesterday I jumped the resistors on the board to see if I can get a constistant idle from start to start. I will let you know how it works out.

I am running MS II, V3 board, and the o-ring style GM IAC.

bluetrepidation · Post by **bluetrepidation** » Wed Aug 16, 2006 12:24 pm

Yes it is fixed. Remember me? Good to see you trying again. There was an error in the code after all. Just load up the latest release. (No need for the beta code.) Also note that you may need to still jumper the IAC resistors on the MS2 processor card. So try with and without. I had no luck with my IAC till the code was fixed and now all is well.

A.J.

69 1/2 Six Pack Bee · Wed Aug 16, 2006 12:29 pm

Nice to see ya again, A.J.!
Yep, I sure remember all of the toil you went through to try and figure it out. I guess Al got on and tweaked the code as I have been reading up on some of the past progress.

At any rate, I am going to start completely from scratch with a V3.00 setup sans relay board and Megaview and just go at it again.

I will be chiming in eventually..

Thanx!

bleoh · Post by **bleoh** » Thu Aug 17, 2006 7:08 am

I run the Jeep 4.0 IAC and once in a while I will get a "hiccup" in the idle speed after a warm restart (high idle), but the vast majority of the time it works fine.

BottleFed70 · Post by **BottleFed70** » Thu Aug 17, 2006 11:56 am

The new code completely fixed my problems.

69 1/2 Six Pack Bee · Thu Aug 17, 2006 12:09 pm

Well then, I guess it is worth diving back into again.

I am one of the "Old Skool" guys who loves simplicity and I can tune the s**t out of a carbed setup but I love the versatility of the Megasquirt and being able to build it and say "look what I did!
Lets see your Holley system do this",.. as the poor sap opens his wallet and shows me the gaping chasm where his hard earned cash used to reside

I just don't want to throw my hands in the air quite yet and I think I have had enough "cooling off" time to vent my frustrations.

bluetrepidation · Post by **bluetrepidation** » Thu Aug 17, 2006 2:14 pm

bleoh wrote:I run the Jeep 4.0 IAC and once in a while I will get a "hiccup" in the idle speed after a warm restart (high idle), but the vast majority of the time it works fine.

My car did this also. Here if you datalog this kind of start you'll see where the MS goes from cranking to run and blips to crank again. The rev is because there is a hard coded time limit of 4 seconds for each IAC movement. So the IAC is stuck at cranking position for 4 seconds causing a high rev then drops down to idle. I just turned my cranking RPM up to 400 and this fixed that from happening.

A.J.

pfabricy · Post by **pfabricy** » Fri Aug 18, 2006 5:00 am

What version of the code fixed it? Is it the v2.36 of the embedded code? I don't want to pull out board and go through all that if I don't need to. I'm running version 2.1. I get it running so nice and then once in a while the idle goes a little high. Drives me nuts.

pfabricy · Post by **pfabricy** » Fri Aug 18, 2006 5:01 am

What version of the code fixed it? Is it the v2.36 of the embedded code? I don't want to pull out board and go through all that if I don't need to. I'm running version 2.1. I get it running so nice and then once in a while the idle goes a little high. Drives me nuts.