Rather than continue hijacking the pinging/knocking thread from @ChaserFJ60 (Pinging/knocking? in a FJ60 with a 2FE. DIZZY TIMING - https://forum.ih8mud.com/threads/pinging-knocking-in-a-fj60-with-a-2fe-dizzy-timing.1261140/) to detail the experimentation with my FJ62's ignition timing, I figured it'd be good to start a new thread for an ignition knowledge base and real world experience.
Yesterday I returned from a 400 mile round trip after setting my initial timing back to 7°. Idle smoothness was unchanged from before, but my performance overall and fuel economy were absolutely atrocious by comparison (this just now occurred to me just before hitting Post, but before I change anything else I'm going to double check and ensure that my E1 and TE1 were properly shorted when I set the timing last Thursday. Will edit this post once I do). If E1 and TE1 WERE properly shorted during the adjustment, then despite @Lead Head giving his explanation of the operation of the ignition portion of the 3FE's ECU (here: Pinging/knocking? in a FJ60 with a 2FE. DIZZY TIMING - https://forum.ih8mud.com/threads/pinging-knocking-in-a-fj60-with-a-2fe-dizzy-timing.1261140/page-5#post-14018058 and here: Pinging/knocking? in a FJ60 with a 2FE. DIZZY TIMING - https://forum.ih8mud.com/threads/pinging-knocking-in-a-fj60-with-a-2fe-dizzy-timing.1261140/page-5#post-14018536 which made enough sense to me to convince me to try going back to factory timing); given what I experienced on this trip, I'm back to my original presumption that the curve itself is controlled by the ECU, using the initial manually set timing as a baseline and increasing from there based on engine RPM and load. How it determines load, if this system does (I honestly doubt it does given how primitive our EFI system is with its lack of knock sensors and other sensors used in modern systems), I would love to find out. But it would involve much more digging on my part once I have the chance to do so.
To detail just how badly my performance was affected, a long steep grade in central WA known as the Orondo Spur that I consistently hold at or within 5 miles over the speed limit in 4th gear since the H55F conversion when climbing was spent with most of the time on this trip not even able to reach the speed limit, and having to downshift to 3rd just to reach the speed limit. Starting off from a level stop I would usually start in 2nd gear with no problem, even with a fully loaded truck and the A/C going. Not this time. The engine lugged bad when I would attempt it and led to me constantly having to start in 1st gear at all stops. This was with a brand new air filter put in just before the trip as well, given how bad the smoke was in my region from the wild fires this summer.
Before I do any more adjustments to the timing I'll fill my tank after work tomorrow and post what my actual fuel economy was.
To also add, I've been using a Mallory 6AL ignition box for I think about 15 years with a Promaster coil. This is triggered by my OEM igniter, which I've been intending to bypass and remove so that the ECU trigger signal would go directly to the Mallory box rather than from the ECU to the OEM igniter and then to the Mallory box. Just haven't gotten to it yet.
Yesterday I returned from a 400 mile round trip after setting my initial timing back to 7°. Idle smoothness was unchanged from before, but my performance overall and fuel economy were absolutely atrocious by comparison (this just now occurred to me just before hitting Post, but before I change anything else I'm going to double check and ensure that my E1 and TE1 were properly shorted when I set the timing last Thursday. Will edit this post once I do). If E1 and TE1 WERE properly shorted during the adjustment, then despite @Lead Head giving his explanation of the operation of the ignition portion of the 3FE's ECU (here: Pinging/knocking? in a FJ60 with a 2FE. DIZZY TIMING - https://forum.ih8mud.com/threads/pinging-knocking-in-a-fj60-with-a-2fe-dizzy-timing.1261140/page-5#post-14018058 and here: Pinging/knocking? in a FJ60 with a 2FE. DIZZY TIMING - https://forum.ih8mud.com/threads/pinging-knocking-in-a-fj60-with-a-2fe-dizzy-timing.1261140/page-5#post-14018536 which made enough sense to me to convince me to try going back to factory timing); given what I experienced on this trip, I'm back to my original presumption that the curve itself is controlled by the ECU, using the initial manually set timing as a baseline and increasing from there based on engine RPM and load. How it determines load, if this system does (I honestly doubt it does given how primitive our EFI system is with its lack of knock sensors and other sensors used in modern systems), I would love to find out. But it would involve much more digging on my part once I have the chance to do so.
To detail just how badly my performance was affected, a long steep grade in central WA known as the Orondo Spur that I consistently hold at or within 5 miles over the speed limit in 4th gear since the H55F conversion when climbing was spent with most of the time on this trip not even able to reach the speed limit, and having to downshift to 3rd just to reach the speed limit. Starting off from a level stop I would usually start in 2nd gear with no problem, even with a fully loaded truck and the A/C going. Not this time. The engine lugged bad when I would attempt it and led to me constantly having to start in 1st gear at all stops. This was with a brand new air filter put in just before the trip as well, given how bad the smoke was in my region from the wild fires this summer.
Before I do any more adjustments to the timing I'll fill my tank after work tomorrow and post what my actual fuel economy was.
To also add, I've been using a Mallory 6AL ignition box for I think about 15 years with a Promaster coil. This is triggered by my OEM igniter, which I've been intending to bypass and remove so that the ECU trigger signal would go directly to the Mallory box rather than from the ECU to the OEM igniter and then to the Mallory box. Just haven't gotten to it yet.
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