I have the mods in my sig.... The engine is sick dunno why....it shakes like mad at idle, stumbles with any amout of pedal, and hunts for an idle rpm. I got the BLMs at 128 at idle and set it a 800rpm and most of the part throttle is 128. The iac counts hold steady but the target and actual as reported by the scanner are way different. However I have tried to to adjust the minumum air without much effect. I looked everywhere for vac leaks but couldnt find any. The timming advance and idle rpm fluctuate like crazy as reported by the scanner. It wont hold steady. I do have a question.....I replaced the pickup coil on the distributor......is there a certain way the gear has to go back on in relation to the rotor position cus when I rebuilt it I just put it back together without thinking.

 

is the module plugged into the pickup correctly i hope so. if not its gonna invert the signal and **** the module off. usually they wont run like that but maybe you have the firing order 180 dergress out. i would check the following

make sure distributor is not 180 out. belive it or not most SBC will run and idle like this. check to make sure that everything is of the correct polarity. also check your firing order on the cap a simple cross os cylinder 5-7 can maker a can run like crap but not backfire.

these are things i would check before doing anything.

 

I am sure it is pluged in correctly and the firing order is correct.

 

did you remove the dtributor to replace the pickup ?? you should have. id still bet on the distributor 180 or a tooth off. check your base timing.

 

Well actually I removed the engine to do the distributor.......I did everything in my sig all at once. It never ran right.....

 

ok these are thing id check cam timing iuf chain has been changed distributor timing firing order.

 

Hehe...this brings back some memories...

They will run like that. Or say you get a module for your car and you plug it in correctly but QC didn't catch the error on the assy line so you hook it up correctly but things don't quite work out like they are supposed to. Not even 180 out.

In the process, 'eyeballing' 0 degrees and adding 6 to the distrib, then popping the cap on will get a rough fire condition. Put a timing light on it and the spark jumps so much, you thought it was on speed. so you don't realize just what is going on.

Scope the EST module lines with the pickup coil and still, nothing looks fishy. Scope SPOUT line with EST reference and you really don't know what the hell you are looking for, but you see a relationship that looks kinda right, so you pass it off as another problem.

Completely give up and start breaking stuff. Including the nub on the pickup coil that prevents you from putting it in correctly. Car fires right up when you but it in the way you couldn't when the pickup coil connector was not broken.

It's a weird thing trying out the experiment later realizing just what causes the problem. With a better timing light, you can see the timing decrease when it would normally increase. Still, you think that spark counts are causing the decrease.

FWIR, the pickup coil produces a square wave that is either supposed to cause the EST module to trigger on the beginning of the signal or the end. Flopping the pickup coil wires will merely cause it to fire opposite of what it is supposed to...maybe not correctly worded, but no doubt truth.

This has nothing to do with this post, but I figured if someone searched for pickup coil in the future, it would help out.

pickup coil
pick-up coil
pick up coil
pick-up-coil

 

ok.....

 

If I disconnect that black/tan wire that you disconnet to set the timming the idle smooths out a lot..... what is wrong here?

 

you either have to much to to little advance. also it could be a sign of a bad module. hard toi say really.

 

Try setting the spark advance for the idle region to the same value. My car had a searching idle and I messed with the minimum air, which you mentioned, and the IAC targed speed deadband for park/neutral and drive, the deadband was set to 25rpm and i changed it to 100rpm for both park/neutral and drive and it now idles decent at 650rpm.