I've been tuning with the ebl flash, and developed an idle surge problem, I've been reading through the threads on this and have been working on the problem. Now my issue is when I come to a stop, the idle drops to about 400 rpm and it takes a while for it to pick up again. I have the idle speed set at 650, but what have I done to cause such a slow recovery?

 

Did you look at stall saver settings? I presume the IAC is functional.

 

The iac is working, it does recover and intermittantly surges after it recovers, takes about 30 sec. I have raise the stall saver rpm twice, but it does not help. I set a flat spark and fuel curve at first int the idle range, but it still surged, I richened the idle a hair and it got better, I changed something that I think changes the speed that the iac moves? but I forgot what it was.

 

You can LOCK idle at a specific SA. It is not a table. I belive it is a flag and you need to specify SA you desire.

You can also do same with LOCK OL Idle. That should enrichen it is the OL table is richer than 14.7 at that rpm/map. I might change all cells around your idle rpm/map cell to say 14.0 and try it.

 

The IAC could be getting sticky and not stepping at each command to step. That will cause a slow recovery.

The other thing is to set the IAC steps to between 5 & 10 on a warm engine with no other loads. This is done via the idle stop screw on the TBI unit.

If the IAC isn't working correctly trying this may lead to frustration. As the idle steps move about aimlessly.

Keep in mind that the ECM displayed IAC steps is commanded. The ECM doesn't really know what they actually are.

RBob.

 

Did you mean to type "where" they actually are?

 

Six of one and a half dozen of another.

Such as: "what is the actual position", versus, "where is the actual position."

RBob.

 

I thought you were up too late watching the Packers crush the Bears.

 

The engine has not been up and running too long for me to think the iac is dirty, but it's easy enough to clean, so I'll try that. I remember reading about what the steps should be, but there was a huge difference in opinions on that. I want to avoid ol idle if possible, to see if it will pass smog without it, but I will look for a flag on the SA. Do you know what it is called?

 

IdleSA I recall. In constants. Look for same in flags as it may need to be checked.

 

I checked the IAC, and it is clean, I checked the counts, and they are way high, I opened the throttle blade and the IAC stopped working at 3% tps. IAC counts are still high, so I guess I need to break out the dremel and adjust the tps?

 

No, just key off for ten seconds and restart the engine. As you opened the throttle the ECM thought you were pushing on the go-pedal and dropped out of idle mode. Can go by the Idle & ClsdThrt indicators on the WUD.

After a restart let the idle stabilize for a minute or so before continuing to adjust the idle stop screw.

RBob.

 

thank you, does that mean I do not need to keep iac voltage around .5 at idle? Or at what point is it too far out?

 

The ECM auto-zero's the TPS. Anywhere from .3 to .8 volts works.

RBob.