[Steve40th]

I have been fighting via tuning, an idle problem. Basically I thought due to my camshaft (xe 230/236) it was just causing reversion and my LT1 just wouldnt idle till warm. Also, people reading my logs were saying you have an exhaust leak or a vacuum leak. I chased that forever. So, I wasnt able to run AC in gear at idle, and warm ups were a little tearful due to richness burning my eyes.
According to Data logging, the IAC was working. Wrong, the PCM was working telling the IAC what do do, but it wasnt.
So, I was looking at open loop tune etc for the idle which allot of people do with larger cams.
But I came across this little photo.
http://shbox.com/1/iac2.jpg
Never thought the IAC was bad per sey, because I was expecting a code, which now I know there is none for IAC in the FSM. Just a resistance check. Well I checked mine, AtoB was bad. Bought a new one and WOW it idles on its own immediately, and even allows AC in gear (Kinda lopey, but the IAC is doing what it can to help idle).
So, lessons learned here guys. Just because you dont have a code, doesnt mean you dont have a problem.

 

[War Machine]

Good heads up! :thumbsup:

I hated dealing w/ the IAC, cleaning and resetting it. :bang

But, once it was set, all was good.

 

[grumpyvette]

thanks for the picture link

http://shbox.com/1/iac2.jpg



http://www.thirdgen.org/tpimod2

yeah thats the problem with EFI, your taught the CPU and codes will locate the problems and point to the source, but its not always the case and theres a zillion things that cause problems that the trouble codes and sensors won,t point too!, in fact theres things that the trouble codes indicate as deffective that may not be!

these are your friends

http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=9365&HS=1

http://www.etoolcart.com/index.asp?PageAction=VIEWPROD&ProdID=9355

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-900010&N=700+115&autoview=sku

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM-800299&N=700+115&autoview=sku

http://www.rbracing-rsr.com/rsrgauge.htm

http://store.summitracing.com/partd...part=SUM-G1059&N=700+-114183+115&autoview=sku

http://www.raytek-northamerica.com/...9b6820919c/1017348120/80_Bro_1-1501_Rev_H.pdf

http://www.centuryperformance.com/vacuum.asp

http://www.amazon.com/Corvette-Inje...918205?ie=UTF8&s=books&qid=1181824450&sr=8-15


KNOWING WHAT YOUR DOING IS IMPORTANT, TO GETTING GOOD RESULTS!
no one knows everything about all models and years so it helps to have the correct procedures and info in a handy referace source,now you can get by with a HAYNES or CHILTONS manual, or something similar, but for detailed info, OWNING the CHEVY SHOP MANUAL FOR YOUR SPECIFIC CAR IS ALMOST MANDATORY!
I get asked frequently, "how did you know how to do that?"
well, EXPERIANCE plays a big roll, working on similar cars and engines helps, and the INTERNET is a good resource... but theres ALWAYS a big need for DETAILED REFERANCE MATERIAL, SPECIFICALLY MATCHING YOUR PARTICULAR CAR and if you have not yet invested in a SHOP MANUAL for the year make and model of you pride and joy muscle car your either not serious about your hobby, or most likely NOT A SERIOUS HOT RODDER! I constantly see guys SCREWING up installations, or adjustments,if you don,t know exactly what your doing, you need to either let the dealer do it and PRAY his mechanics are experianced and can read, OR..if your like ME, you would rather do it yourself and KNOW its been done correctly...
if your not aware, heres where to order them....

1-800-782-4356

http://helminc.com/helm/homepage.asp?r=

your average shop manual may cost $100-$150 ONCE! but youll easily save far more than that in reduced time and screw ups in under a years time or in many cases on one job vs having the dealer do the work!

 

[Steve40th]

I drove with AC on and absolutely drove flawless. No misses, no smell of fuel. It just drove like it was tuned to.