Well I've been trying to get my VE table dialed in with the EBL flash and so far I've managed to get what I consider a very nice idle. After adjusting the VE table around my idle I figured I'd try and allow it to go closed loop to see what that would be like. I've undone the changes made for VE learn.

The engine starts and warms up just fine, but it wont go into closed loop anymore. The only things I changed other than the low speed VE table was to modify the Crank AFR rows 8-151 fixed at 12.8 and I also zeroed out the choke AFR. I made those changes because the engine seemed very very rich at idle till it went Closed Loop. What are these two tables really for?

I figured the VE table was way off so I thought fixing the idle was a good place to start. But I don't understand how I lost CL operation. Any thoughts? The O2 sensor seems to swing strangely at times.

My setup is a 355,CNC 195cc heads, 219/219 .520 lift, ported Edelbrock manifold,48mm TB etc...

Kelvin

http://home.comcast.net/~f12x/blazerlog.dat

 

Well for starters look at the documentation that came with your EBL. There is substantial info on what all the adjustments are for. If you are that rich at startup you will need to mod the crank AFR tables according to what fuel pressure you are running. The .BIN that came with the EBL is for a stock 305 engine. IMHO zeroing out the choke AFR is not the correct way to take care of your cold start issue. Make sure you have the correct BPC calculated and adjust your fueling tables accordingly and you will be alot closer...Not perfect but at least within 20% With the overlap on that cam you will find it a challenge to get closed loop idle correct. Where is your o2 sensor located? is it heated? your o2 sensor may not get hot enough to go closed loop depending on the answers to those questions.