Gary Lewis Posted August 10 Share Posted August 10 Yep that’s why my trucks can live with short term memory loss. I’m about to most likely acquire a 93 F250 with the 460 EFI very soon from El Reno, OK. Next week. I can’t do that battery disconnect any more, I guess ? Wrong terminology. You "can" do it but "shouldn't". The systems learn what it takes to make the engine run correctly and will forget that if you remove the power. So you'll go through the learning exercise each time if you disconnect the battery and your trip may be over before it learns everything again. Link to comment Share on other sites More sharing options...
viven44 Posted August 10 Share Posted August 10 Wrong terminology. You "can" do it but "shouldn't". The systems learn what it takes to make the engine run correctly and will forget that if you remove the power. So you'll go through the learning exercise each time if you disconnect the battery and your trip may be over before it learns everything again. Okay! (Yes was being goofy - millennial flaw) I came with experience from the post OBD-II world when I got into these trucks… yes I’m loosely aware of PCM/ECM tables and how things are relearned. I’m just about to graduate from carburetors and enter the world of early EFI pre-OBD-II. A bit nervous…. Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 10 Share Posted August 10 Okay! (Yes was being goofy - millennial flaw) I came with experience from the post OBD-II world when I got into these trucks… yes I’m loosely aware of PCM/ECM tables and how things are relearned. I’m just about to graduate from carburetors and enter the world of early EFI pre-OBD-II. A bit nervous…. The speed density/bank fire systems work well - if you don't change much. The range of adjustment in the ECU is fairly small as it assumes it knows how much air was just ingested at a given RPM with a given throttle opening. So if you change the cam, or the intake, or the exhaust it won't really know and it may not be able to adjust far enough to make it work correctly. That's where the mass airflow (MAF) systems come in. They don't assume, they measure. So then they can do the math to determine how much fuel is needed, and they have a table that tells them how long to open the injectors to get that much fuel. But they monitor the output via the O2 level and learn how much to adjust from their table to get the right amount of fuel and, therefore, the AFR they are supposed to be at. And it is that learning that you lose when you pull the battery. Link to comment Share on other sites More sharing options...
grumpin Posted August 10 Share Posted August 10 Okay! (Yes was being goofy - millennial flaw) I came with experience from the post OBD-II world when I got into these trucks… yes I’m loosely aware of PCM/ECM tables and how things are relearned. I’m just about to graduate from carburetors and enter the world of early EFI pre-OBD-II. A bit nervous…. I like EFI the on those. I had a 94 F250 with the 460 and E4OD. And the 92 Bronco. Like Gary said they’re not MAF and assume, estimate or guess on parameters but reliable and work well. Get one of these, https://www.innova.com/products/digital-ford-code-reader-1981-1995-3145 Or similar, I was happy with Innova. Link to comment Share on other sites More sharing options...
85lebaront2 Posted August 10 Share Posted August 10 Wrong terminology. You "can" do it but "shouldn't". The systems learn what it takes to make the engine run correctly and will forget that if you remove the power. So you'll go through the learning exercise each time if you disconnect the battery and your trip may be over before it learns everything again. Gee, when did we learn this? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 10 Share Posted August 10 Gee, when did we learn this? Is that in reference to can’t, shouldn’t, or will? 😎 I think I learned “will” the first time I pulled Fuse 9. (Going from 77 yo memory here, but it’s younger memory than some. 😉) Link to comment Share on other sites More sharing options...
viven44 Posted August 10 Share Posted August 10 I like EFI the on those. I had a 94 F250 with the 460 and E4OD. And the 92 Bronco. Like Gary said they’re not MAF and assume, estimate or guess on parameters but reliable and work well. Get one of these, https://www.innova.com/products/digital-ford-code-reader-1981-1995-3145 Or similar, I was happy with Innova. Thanks Dane and Gary. Look forward to learning more about these! Push comes to shove, and I need to get through wilderness or a cartel zone, carburetors are still very much in the comfort zone today for this millennial ... what an oxymoron:nabble_smiley_thinking: Link to comment Share on other sites More sharing options...
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