ok, the timing is at 14* both in drive, and park. I believe tho SA table shows 26.02 while idling, shouldnt it match up?
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ok, the timing is at 14* both in drive, and park. I believe tho SA table shows 26.02 while idling, shouldnt it match up?
It depends on the bin and warm spark bias which is usually 9.86 degrees for SBC 7747, where BBC 7747 warm spark bias is 0. So you are only off by 2 degrees and that is probably to do with Spark Latentcy Correction which is not accurate in a stock bin... I don't think that is your issue but you could try and add 5 degrees timing at idle to see if it helps? If it does then changes are needed in bin before any WOT high RPM driving.
You've got good high vacuum and don't sound to be a newb at this...does MAP in TunerPro convert to same high vacuum? Wondering if there is a leak or faulty MAP sensor? If you can't find any vacuum leaks maybe pull and read plugs, you will find one or two off if you have a vacuum leak under intake...
Ok, going to run to the store, then I will compare the TP MAP to my vac gauge...funny, was just thinking this in the shower, of all places!
Base timing is now set at 5*
both logs were taken when i got back from the store.
1st log, 619idle, is where she is pretty happy, no surging, but 0 idle counts.
2nd Log, 619idle2, i backed off the idle screw to get the iac to open up. i aimed for 20 counts, but got closer to 40 at restart. Surges Pretty bad
MAP is spot on with the vacuum gauge.
I am a newbee at tuning. Before, I just did wiring and installed EFI components in place of Old School Carb systems. This tuning stuff is all Greek to me.
Must turn off engine to reset TPS to 0 % when restart. Or just disconnect battry to clear learn and see where she ends up. Second one was not that bad for IAC counts considering the idle variation
Notice that Rich BLM too?Is there anything that could occure in the ECM to cause the rich condition? I have literally gone over the engine over 50 times looking for faults. 5 of those with all the vacuum accessories plugged off.
Just went out and fired it up and watched it through TP. BLMs Perfect at 128, o2 voltage eventually climbed to over 700, and the engine ran smooooth, at 800.
Then it went into CL, o2 voltage shot down to the 3 to mid 400's, and the idle went to hell.
So it was idleing smooth in OL and went CL and went to hell? Hmm... the O2 readings you are seeing are cross counts, supposed to be there.
Have you read the plugs on O2 sensor side yet?
Yeah, thats one of the first things I did. They did look a little on the rich side.
Going to pull,the drivers side manifold and inspect it, Low o2 voltage after going into closed loop makes me think air is getting in there somehow. I do have a little tick under accelleration.
Well, thats it. I cant think of aything else that could cause this. I know the engine has the ability to run right, because its a dream in OL, BLM and INT are both at 128.
I did notice that the o2 sensor seemed to stall out for quite a long time...the voltage did not change for about 30 seconds...so the sensor will be replaced soon.
Injectors will be sent out for a professional cleaning.
Maybe the after market cam? I dunno. Maybe pull the wiring harness back out and go through it again.