UPDATE-Does this look like a problem to you??????
 

With my MEFIBurn SW now loaded and working I was monitoring my motor, the timing is all over the place. I mean from 0* to about 20* advance all at idle. So I pulled the distributor cap and look what I found. This might be an issue with my overall performance? Any thoughts? New Dis stock replacement or not?

I can't believe it even runs:eek:

The ECM uses timing (and IAC position) to control idle speed. Rapidly changing ignition timing is normal at idle. If your concerned about a distributor problem, check the timing with a timing light in Base Timing Mode. It should be very steady then.

As far as the rust and corrosion, your distributor looks like most Delco EST distributors. It could use a little clean-up, but it should be fine.

When monitoring your engine at idle speed, one of the most important things to check is the engines ability to achive and maintain it's Desired Idle Speed. An engine that is running well should maintain the desired idle speed with RPM variation of no more than 10 to 15 RPM either way. For example, if the Desired Idle Speed is 650, idle speed should vary from about 640 to 660 but no more than that.

I cleaned the distributor, installed new plugs cap rotor and wires. The base timing is steady. As far as the steady RPM this is not like you are saying 10-15 RPM mine swings between 60 & 80 RPM. I can trend the IAC vs RPM but I'm not sure what/how the IAC should be reading.

My Delco distributor looked even worse and was not working, it needed a new pickup coil (which means you have to pull it totally apart to change) so instead I bought a whole new sealed assembly for around $400. Dropped it in and was going again in 10 min.

My Idle was crazy as well. It turned out to be the linkage was not allowing the throttle to go down all the way. It was up just a hair which made it idle wildly like yours. I diagnosed by removing the throttle cable from the peg which allowed it down all the way and then all was fine so I knew it was the linkage.

I had the distributor out and completly apart to clean it. The module tested fine. he pickup coil I guess I could have replaced seeing as I was in there. I guess it could be breaking down at higher RPM? No big deal to pull it back out and replace the coil. I will look into the throttle linkage/adjustment today. Thanks for the heads up.

I was worried, to get the dist out I had to remove the intake plenum so lots of wires, sensors, etc. messing with. I figured I broke one of those, I was glad it turned out to be the linkage which got slightly out of adjustment as I removed & reinstalled the plenum etc. The first run the idle was all over, then easy fix thankfully. Been fine since. I have a stock 502 Magnum MPI, 1996, Gen VI.

Those Delco distributors must trap water to look so bad so fast.

Yes the linkage could be one of my problems but I'm not holding my breath. That would be great though if it was. I also have a 502 well 509 really, with the cap off you can get the distributor out pretty easy. Two plugs on the back and the clamp. I thought the same thing about removing the intake plenum. I was ready to do so looking at the distributor, but it worked out ok.

Quick diagnosing just unhook the linkage from the throttle body and see. Hopefully it's that simple. Good luck.

Hey Warlock, I just posted on another thread about using the MEFIburn.... good stuff. I ended up with IAC counts around 30 or so at idle with a TPC voltage of around .55 I think a target number should be around 20 IAC counts with a TPC reading of .500, but I could not adjust mine to reach that number (don't hold me to those numbers, I just remember reading that in these forums)

Anyway, mine seems to run well and as Dave_N said, at idle the timing will jump all over the place as the
ecu constantly adjusts.

You probably already know, but you can set the TPS to meet your desired number and then open or close the secondary "butterfly" to meet the desired IAC counts. You will notice the idle stays the same as the IAC adjusts to maintain the programmed idle speed.

Good luck!