Fixing over compression on a 2FE (Camshaft analysis?) (1 Viewer)

[Lead Head]

This has been my only car ever, My other one is a 1966 Toyota Sports 800 thats cut in half.
I wonder if theres a way to trick the ECU into never over advancing the dizzy. or catch and modify the signal from the ECU to the dizzy. I bet you sombody can but not me not yet.

Regardless. pinging has been already greatly reduced and only occurs during hard load, I feel like if this was a huge issue nobody would de-smog their fj62 at all ever. Theres no economic scenario where I can entertain spending more than $300. I don't drive my FJ60 to feel cool, Its because it was a hand me down when I was in high school and I dont have the money for any decent rig that wouldn't require $1000's more in repairs. Parking this truck is not an option unfortunately

There is no ECU signal from the ECU to the distributor. The ECU picks up the camshaft position from the distributor, and then directly fires the coil in response. Toyota ECUs of this period have Mask ROM processors, which means its nearly impossible to change the programming. Your only real option is to go to aftermarket engine management if you want to change the ignition timing map.

Pinging during hard load is literally the absolute worst type of pinging. That is when your piston, piston rings and piston ring lands are being hammered the hardest. This is what pinging does to a 2F: How not to build the 2F - https://forum.ih8mud.com/threads/how-not-to-build-the-2f.563170/page-8#post-12229159

As far as your economic scenario goes: If you don't have any more money at all to put into this rig (by your own admission, you said you don't have the money to take the head off, etc...) - not even $300 - how do you plan to fuel it? At 10-12 MPG, you're going to be looking at $250-300/month in fuel alone.

The best way to get your timing right is to use a vacuum gauge connected to a port in the central plenum of the intake, AFTER the throttle body. What you'll want to to is advance your timing (with the ICS disconnected) until you reach the highest idle vacuum on the gauge, and then retard it back 2 inHg. That's the most foolproof method to reach your ideal initial timing without risk of pinging. The curve, like was said earlier in the thread, is a much different beast, but since we're not really hot rodding our engines a great deal the stock setup will be just fine once you get your initial dialed in.

Sorry but this is bad advice. That is only relevant on a mechanically timed vehicle. The 3FE has electronically controlled timing. The 3FE's computer controls ignition timing advance at idle to do a few of different things. It will vary ignition timing to try and maintain the smoothest possible idle, it will vary timing to account for small changes in idle load (turning the steering wheel, headlights on) and will vary ignition timing to account for the A/C compressor. Setting the base timing WITHOUT jumping the diagnostic port is just going to result in extremely retarded ignition timing - even using the vacuum method.

Since he has a modified, high compression engine with the EGR deleted - his best bet is going to be to run premium fuel and then retard the ignition timing until ALL pinging is eliminated.

 

[OSS]

I stand corrected with my non relevant info I previously posted that related to the 2F engine and not the 3FE. I'll keep my trap shut on 3FE issues from now on cuz I obviously don't know what I'm talking about with that engine.

 

[ChaserFJ60]

There is no ECU signal from the ECU to the distributor. The ECU picks up the camshaft position from the distributor, and then directly fires the coil in response. Toyota ECUs of this period have Mask ROM processors, which means its nearly impossible to change the programming. Your only real option is to go to aftermarket engine management if you want to change the ignition timing map.

Pinging during hard load is literally the absolute worst type of pinging. That is when your piston, piston rings and piston ring lands are being hammered the hardest. This is what pinging does to a 2F: How not to build the 2F - https://forum.ih8mud.com/threads/how-not-to-build-the-2f.563170/page-8#post-12229159

As far as your economic scenario goes: If you don't have any more money at all to put into this rig (by your own admission, you said you don't have the money to take the head off, etc...) - not even $300 - how do you plan to fuel it? At 10-12 MPG, you're going to be looking at $250-300/month in fuel alone.



Sorry but this is bad advice. That is only relevant on a mechanically timed vehicle. The 3FE has electronically controlled timing. The 3FE's computer controls ignition timing advance at idle to do a few of different things. It will vary ignition timing to try and maintain the smoothest possible idle, it will vary timing to account for small changes in idle load (turning the steering wheel, headlights on) and will vary ignition timing to account for the A/C compressor. Setting the base timing WITHOUT jumping the diagnostic port is just going to result in extremely retarded ignition timing - even using the vacuum method.

Since he has a modified, high compression engine with the EGR deleted - his best bet is going to be to run premium fuel and then retard the ignition timing until ALL pinging is eliminated.

Let me worry about my own economic struggles. Thats literally none of your concern. Im talking about money to spend on another insurance plan, registering another car, finding one cheap enough but not total poo, I'm looking for advice on how to fix my engine not a reason to give-up and park it.

Seeing how @Spook50 literally wrote the manual on desmogging an FJ62 and has had the same issue im having in his thread and managed to fix it, as of now im more inclined on to at-least trying his way of doing things and see if I get an improvement. Like I mentioned earlier I think I set my timing before without jumping the TE1 and E1 ports and managed to get little to no pinging. Maybe with my build a highly retarded timing is the only way to go

The guy in the "How not to build a 2F" yanked his distributor as far as it would go, I'm not quite there yet haha.

 

[Spook50]

There is no ECU signal from the ECU to the distributor. The ECU picks up the camshaft position from the distributor, and then directly fires the coil in response. Toyota ECUs of this period have Mask ROM processors, which means its nearly impossible to change the programming. Your only real option is to go to aftermarket engine management if you want to change the ignition timing map.

Pinging during hard load is literally the absolute worst type of pinging. That is when your piston, piston rings and piston ring lands are being hammered the hardest. This is what pinging does to a 2F: How not to build the 2F - https://forum.ih8mud.com/threads/how-not-to-build-the-2f.563170/page-8#post-12229159

As far as your economic scenario goes: If you don't have any more money at all to put into this rig (by your own admission, you said you don't have the money to take the head off, etc...) - not even $300 - how do you plan to fuel it? At 10-12 MPG, you're going to be looking at $250-300/month in fuel alone.



Sorry but this is bad advice. That is only relevant on a mechanically timed vehicle. The 3FE has electronically controlled timing. The 3FE's computer controls ignition timing advance at idle to do a few of different things. It will vary ignition timing to try and maintain the smoothest possible idle, it will vary timing to account for small changes in idle load (turning the steering wheel, headlights on) and will vary ignition timing to account for the A/C compressor. Setting the base timing WITHOUT jumping the diagnostic port is just going to result in extremely retarded ignition timing - even using the vacuum method.

Since he has a modified, high compression engine with the EGR deleted - his best bet is going to be to run premium fuel and then retard the ignition timing until ALL pinging is eliminated.

The 3FE has an electrically controlled curve, but I would argue that the initial timing is still set mechanically; hence why there's a procedure to do it in the FSM. The computer control in a 3FE is very primitive by today's standards. While I can't argue with any certainty that timing is or isn't changed on the fly based on small changes in engine loading (such as your examples), I would be very surprised if that's the case. A newer, fully electronic ignition, sure, but I'm highly doubtful that's the case with these.

Now whether shorting the diagnostic leads or not while using the vacuum method is the best method, I can't say because I haven't tried it with them shorted. I intend to try it to see if any overall difference results. Also curious to find out if that disables the ICS or not. I can say though that since I advanced my initial timing over a year ago my performance was very noticeably improved, most obviously when climbing long grades and holding speed before feeling the need to downshift.

 

[Lead Head]

It's important to understand what "base timing" means in the context of an EFI vehicle with electronically controlled ignition. In a carb'd vehicle, when you set your base timing, you're setting the absolute minimum amount of spark advance - in other words your fully retarded position. That is not true in an EFI vehicle with electronic ignition. The computer is actually capable of retarding the ignition timing beyond the mechanical base timing. It's possible for EFI systems to even have negative degrees of advance!

The only thing setting the "base timing" does on an EFI vehicle, is set he camshaft position sensor accurately relative to the actual mechanical position of the engine. To do this process normally would require a special tool capable of reading the signal from the cam position sensor, and you'd have to reference that to the crankshaft position somehow, and it'd all be complicated. Toyota has engineered this EFI system so that when you jump TE1 and E1, it will disable the timing control system and fire the spark at a fixed degree. This allows you to properly set the camshaft position sensor using standard timing tools (timing light). Toyota has done the math for you, so that when TE1 and TE are jumped, and you turn the distributor so the timing light hits the 7° mark - the camshaft position sensor is now properly "timed" to the engine.

Toyota (and every other automaker) use dynamic spark control to make the engine run smoother to account for slight changes in load, especially during idle. Yes, even on a computer as old as the one in the 3FE. If Toyota did NOT implement dynamic timing at idle - why would you need to ever jump TE1 and E1 to set base timing? The answer is the computer is constantly adjusting timing all the time, so trying to set timing without jumping TE1 and TE is unreliable. When you pull that jumper, the computer sets the timing to what it wants - and at idle that usually means you're going to see some advance beyond the base timing. So if you set timing by "feel" or by "light" without the jumper in, you're going to end up significantly retarding your timing. This is evidenced by Spook50 saying after he set his base timing, he gained a notable performance increasing by advancing his distributor - that's because he was starting out very retarded.

When you turn the distributor to anything but "base timing", you are offsetting the entire ignition map. If you block off the EGR, get pinging, and need to turn the distributor back - you are retarding the ignition timing globally. So that means you are actually giving up power at every point the EGR valve would normally be closed (including full-throttle operation).

So to repeat:
- 1) Get the highest octane fuel you an afford and fill the tank
- 2) Fix every single vacuum leak. Check over the intake tube with a fine-tooth comb - it CANNOT have any leaks.
- 3) Set base timing to 7° with TE1 Jumped
- 4) Retard distributor 1° at a time until ALL pinging is eliminated.

That is the absolute best you can do at this point without switching to a different engine management ...and just to reiterate one more time

Pinging at high load will destroy your engine.

 

[Spook50]

It's important to understand what "base timing" means in the context of an EFI vehicle with electronically controlled ignition. In a carb'd vehicle, when you set your base timing, you're setting the absolute minimum amount of spark advance - in other words your fully retarded position. That is not true in an EFI vehicle with electronic ignition. The computer is actually capable of retarding the ignition timing beyond the mechanical base timing. It's possible for EFI systems to even have negative degrees of advance!

The only thing setting the "base timing" does on an EFI vehicle, is set he camshaft position sensor accurately relative to the actual mechanical position of the engine. To do this process normally would require a special tool capable of reading the signal from the cam position sensor, and you'd have to reference that to the crankshaft position somehow, and it'd all be complicated. Toyota has engineered this EFI system so that when you jump TE1 and E1, it will disable the timing control system and fire the spark at a fixed degree. This allows you to properly set the camshaft position sensor using standard timing tools (timing light). Toyota has done the math for you, so that when TE1 and TE are jumped, and you turn the distributor so the timing light hits the 7° mark - the camshaft position sensor is now properly "timed" to the engine.

Toyota (and every other automaker) use dynamic spark control to make the engine run smoother to account for slight changes in load, especially during idle. Yes, even on a computer as old as the one in the 3FE. If Toyota did NOT implement dynamic timing at idle - why would you need to ever jump TE1 and E1 to set base timing? The answer is the computer is constantly adjusting timing all the time, so trying to set timing without jumping TE1 and TE is unreliable. When you pull that jumper, the computer sets the timing to what it wants - and at idle that usually means you're going to see some advance beyond the base timing. So if you set timing by "feel" or by "light" without the jumper in, you're going to end up significantly retarding your timing. This is evidenced by Spook50 saying after he set his base timing, he gained a notable performance increasing by advancing his distributor - that's because he was starting out very retarded.

When you turn the distributor to anything but "base timing", you are offsetting the entire ignition map. If you block off the EGR, get pinging, and need to turn the distributor back - you are retarding the ignition timing globally. So that means you are actually giving up power at every point the EGR valve would normally be closed (including full-throttle operation).

So to repeat:
- 1) Get the highest octane fuel you an afford and fill the tank
- 2) Fix every single vacuum leak. Check over the intake tube with a fine-tooth comb - it CANNOT have any leaks.
- 3) Set base timing to 7° with TE1 Jumped
- 4) Retard distributor 1° at a time until ALL pinging is eliminated.

That is the absolute best you can do at this point without switching to a different engine management ...and just to reiterate one more time

Pinging at high load will destroy your engine.

Very interesting explanation, and that does make a lot of sense. So it looks like I stand corrected in my interpretation of how our ECU controls the timing and curve. I'm curious to do some comparisons now to see just what affects what as far as setting initial timing via vacuum and where that lands when verifying with a timing light, and then setting with the timing light (if it's any different from what I end up with by using vacuum with the terminals shorted).

I just wish the window wasn't such a PITA to see on an F engine.

And yes when figuring something out I typically start out retarded....

 

[ChaserFJ60]

The FJ62 dosent have a camshaft position sensor, the cam is locked in place with a gear directly to the crank and should never change its position unless you manually swap out the FJ60 cam gear for the Fj62 gear which is 5* advanced (im running with the FJ60 gear). Im just gonna turn the dizzy back to restrict its maximum spark advance capability to where it cant ping and hope it can adjust itself normally under other circumstances below my preset maximum. Thats all I can do.

 

[F226continental]

Read Lead Heads explanation closer, the distributor is the camshaft position sensor, once you set it correctly

 

[OSS]

From the 3FE manual

 

[tmxmotorsports]

The air intake hose is still available from toyota @cruisermatt posted this up somewhere he may chime in amd give up the part # for it or try and message him about it @Spook50 im retarded too but what @Lead Head is saying does make sense.

 

[Seth S]

From the 3FE manual

View attachment 2768195

 

[Lead Head]

Read Lead Heads explanation closer, the distributor is the camshaft position sensor, once you set it correctly

From the 3FE manual

View attachment 2768195

Yup! In Toyota EFI Land "NE" is the crank-angle sensor/crankshaft position sensor, and "G" is the camshaft position sensor/"cylinder identification" sensor. For the 3FE, to keep things simple, they integrated both sensors into the distributor. The "NE" sensor indirectly infers crankshaft angle based on the distributor shaft position. You can see the two "points" on the G sensor. Those points correspond to TDC Compression for a "pair" of cylinders - probably Cylinder 1 and Cylinder 6 as determined by the camshaft timing. So essentially it's determining the camshaft position relative to the crankshaft using the G sensor.

Later motors stopped putting the crank sensor in the distributor. There's too much slop from timing chain/gears/distributor drive, so it's more accurate to directly read the crank position.

 

[Spook50]

Yup! In Toyota EFI Land "NE" is the crank-angle sensor/crankshaft position sensor, and "G" is the camshaft position sensor/"cylinder identification" sensor. For the 3FE, to keep things simple, they integrated both sensors into the distributor. The "NE" sensor indirectly infers crankshaft angle based on the distributor shaft position. You can see the two "points" on the G sensor. Those points correspond to TDC Compression for a "pair" of cylinders - probably Cylinder 1 and Cylinder 6 as determined by the camshaft timing. So essentially it's determining the camshaft position relative to the crankshaft using the G sensor.

Later motors stopped putting the crank sensor in the distributor. There's too much slop from timing chain/gears/distributor drive, so it's more accurate to directly read the crank position.

It occurred to me earlier this evening that the reason I had resorted to using vacuum years ago to set my initial timing was because it's such a PITA (read: damn near impossible) to see the timing marks on the flywheel with my (older than me) timing light. To compare to what I'm at now, I'm going to go ahead and start from square one with setting it to factory following the FSM procedure, BUT first I need to find a timing light that is going to work well for allowing me to hold it, adjust the distributor, AND see the flywheel. Any recommendation on one?

I really wish these had timing marks on the crank pulley like my old Duster's slant six did....

 

[Seth S]

3FE distributor guts:

It occurred to me earlier this evening that the reason I had resorted to using vacuum years ago to set my initial timing was because it's such a PITA (read: damn near impossible) to see the timing marks on the flywheel with my (older than me) timing light. To compare to what I'm at now, I'm going to go ahead and start from square one with setting it to factory following the FSM procedure, BUT first I need to find a timing light that is going to work well for allowing me to hold it, adjust the distributor, AND see the flywheel. Any recommendation on one?

I really wish these had timing marks on the crank pulley like my old Duster's slant six did....

Old trick is to paint the tdc and timing marks with some whiteout. Makes them much easier to see with the light. As for lights I have a nice snap on unit but there are many similar ones today that can be increment/decremented to help determine your timing.

my light looks like this:

Snap On Timing Light (MT2261) | eBay

Snap on tools timing light.

www.ebay.com

But I bet there are newer other brands for less money that work just as well

 

[OSS]

Any recommendation on one

I replaced my dim cheapo timing light with a bright Innova Electronic Timing Light with Digital Advance and Tach Functions #3568.

It works great and is plenty bright. But you still can't use it in direct sunlight. In a garage is fine or in the shade of a tree.

 

[Spook50]

I replaced my dim cheapo timing light with a bright Innova Electronic Timing Light with Digital Advance and Tach Functions #3568.

It works great and is plenty bright. But you still can't use it in direct sunlight. In a garage is fine or in the shade of a tree.

I think a newer Innova is what my local parts store has for a loaner. I'll have to see if I can do it before my road trip this weekend so I can get a good idea if there ends up being a difference in performance on grades and overall fuel economy with the FSM procedure versus how mine is set now.

Leave it to threads like this to get me to want to tinker more....

 

[cps432]

I replaced my dim cheapo timing light with a bright Innova Electronic Timing Light with Digital Advance and Tach Functions #3568.

It works great and is plenty bright. But you still can't use it in direct sunlight. In a garage is fine or in the shade of a tree.

I have one of those and I love it. I keep it in the truck.

 

[gbogh]

I will also chime in with the Innova 3568. Really nice for setting timing because of the tach and advance degrees function.

 

[Spook50]

So here's a question as far as positioning; how have you been able to see the window and hold the timing light at the same time while moving the distributor?! I'm fairly tall and pretty broad built, so worming my way in there isn't an easy task (really the biggest reason I stopped trying to use a timing light so long ago).

 

[MoaByte]

So here's a question as far as positioning; how have you been able to see the window and hold the timing light at the same time while moving the distributor?! I'm fairly tall and pretty broad built, so worming my way in there isn't an easy task (really the biggest reason I stopped trying to use a timing light so long ago).

I'm 5' 9" and use a plastic step.