Tuned PE screen shot from a '427 PCM

I have a couple screen shots after tuning the PE on a '427 PCM.:thumbsup: Standard DISCLAIMER "USE AT YOUR OWN RISK"!:yikes:

dave w

:laugh: Isn't that crazy what you have to do to get PE to work? We had a discussion on that and 93V8S10 did a graph of all the qualifiers, it was an unbelievable amount of work he did to document how PE was finally enabled. It used to be controlled by your foot hitting the gas.

When my son was driving me around in his truck with the TBI conversion and I was emulating getting things close, I had everything set and then took out the delay and told him to go through a couple gears again full throttle. He did and said "Holy $%*@" what did you do? Ha!

I found just as many things as you show above, just ridicules to get PE! Most bins I looked at were 60 seconds and up delay time to enter PE? By that time I would not need PE anymore... :mad1:

I'd guess the only reason it is there with that delay would be to cool cat converters down? Like towing a trailer up a long mountain grade...

emissions/MPG.

in the 93-95 speed-density 3100 code, the PE delay is based off of D-TPS when getting near the PE threshold. i zero'd the table as one of the first things i did in my calibration. spins the tire a bit more easily at low speeds when easing on the throttle..... for better or worse. :D

Mine seems to enter PE quite easily. <shrug> Any time I stomp on the pedal it goes into PE once the TPS is past a certain point. No delays.

For me, I don't care what the Butt Dynometer measures for PE ... if it doesn't show up in Excel, it didn't happen.:laugh:

dave w

While we are on the subject of PE for the 7427, I have a question about mine.
I remember back when I was still learning the 427 and my PE was not working, turned out to be the PE delay was like 110 seconds!
But now I notice, if I punch it, PE shows active on the datalog screen instantly, however it takes several seconds for the WB AFR to drop to 12.5 (where I have PE set) I am usally pretty much done by the time its finally down to 12.5. I usally only have about 1-2 seconds or less of actual 12.5 afr when I have been in pe for several seconds. Should it not drop down to the 12.5 almost instantly? Once pe shows active on the datalog screen, afr slowly starts dropping, like .5 every second or so.

Quote:

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Originally Posted by JeepsAndGuns

While we are on the subject of PE for the 7427, I have a question about mine.
I remember back when I was still learning the 427 and my PE was not working, turned out to be the PE delay was like 110 seconds!
But now I notice, if I punch it, PE shows active on the datalog screen instantly, however it takes several seconds for the WB AFR to drop to 12.5 (where I have PE set) I am usally pretty much done by the time its finally down to 12.5. I usally only have about 1-2 seconds or less of actual 12.5 afr when I have been in pe for several seconds. Should it not drop down to the 12.5 almost instantly? Once pe shows active on the datalog screen, afr slowly starts dropping, like .5 every second or so.

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I've also noticed the WBO2 lag when PE becomes active. I use Excel to monitor the injector DC to verify PE is working, which confirms to me the WBO2 is just flat out lagging.:thumbsup:

dave w

Of course there is a time delay. Even standard O2 readings lag because it takes time for the fuel to be injected, reacted, and exhausted. The amount of delay will depend on the sensor location, exhaust temp, and sensor controller itself. If you can get used to the delay then you can learn to read PE after the fact.

Interesting, I had no idea there was that much of a delay.

This all sounds interesting, I may have to look over some past datalogs, because I think I remember that my '7427 only takes a couple of samples (<.5 seconds) to show rich when PE activates.