I know this is a long shot, but .... UPDATED AND EDIT for current discussion which is now EFI output wire and too much crankcase pressure

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
I'm pretty sure my Ne pickup coil is shot, but it would be nice have these on-hand anyways. Cardone rebuilds them, so there has to be someone making them.
 

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,993
Location
MKE, WI
I have the same question for this and a lot of other sub-systems!

They get these parts somehow....

I have a spare CPS lying around here I could rebuild if I could get new coils.

Another option could be to disassemble one, measure the wire gauge/wraps and length.
Rewind one by hand (possibly with enhancements), and re-pot to seal the open ends....
The magnet wire gauge is very very small, like 42 gauge.
 
  • Like
Reactions: the t3d

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
I think it would be prudent to take apart and inspect the magnet if it survives the depotting.
specifically the geometry of the magnet.

the magnet strength, you don't want to make it to strong as that is directly related to voltage. The last thing we want is 140+ VAC from the CPS. (not possible due to speed and size of the trigger wheel but as an example).
 
  • Like
Reactions: the t3d

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
I have the same question for this and a lot of other sub-systems!

They get these parts somehow....

I have a spare CPS lying around here I could rebuild if I could get new coils.

Another option could be to disassemble one, measure the wire gauge/wraps and length.
Rewind one by hand (possibly with enhancements), and re-pot to seal the open ends....
The magnet wire gauge is very very small, like 42 gauge.
Yeah, that would be interesting to try but I don't know enough to be able to take all that apart without messing up something.

Do you think if I called Cardone, I could find more information? I feel like that's something they wouldn't want to share.
 

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,993
Location
MKE, WI
You could try but I doubt they would disclose anything.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
I think it would be prudent to take apart and inspect the magnet if it survives the depotting.
specifically the geometry of the magnet.

the magnet strength, you don't want to make it to strong as that is directly related to voltage. The last thing we want is 140+ VAC from the CPS. (not possible due to speed and size of the trigger wheel but as an example).
Ha that's a good point. I know the CPS voltage can only be seen using an oscilloscope, but is that also true for the 5v signal voltage from the ECM to the igniter?

My car has gone back to cranking with no spark or rpm signal to the tach. The voltage on DVOM on that signal wire is only 0.4v when cranking. I've run a whole new wire from the computer to the igniter, I've grounded the computer, swapped computers, replaced the CPS harness and connectors, enhanced the grounds to the igniter, benchtested the igniter, and wired in New wires inside the CPS up to the magnets themselves.

Literally the only thing I haven't done is swap the CPS with another one. That's why I'm leaning towards a pickup coil being shot. No codes. It's super annoying as it was running perfect like a week ago after I jumpered that signal wire directly like a few inches from the computer to a couple inches from the igniter connector.

It sat for a few days. I disconnected the battery, I replaced the steering wheel, went to start it, and got the same damn crank, no start issue. Makes zero sense to me!
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
You could try but I doubt they would disclose anything.
I remember Aaron from driftmotion saying he was going to try and source them in the CPS magnet mod video he made, but don't know if he has looked into it yet.

Would you mind looking at my last reply before this one and let me know what you think about my current situation?
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
Just to rule out other simple things.
Do you have an STA signal at the ECU during cranking?

Also.
What is the air gap on the coils and the resistance of each coil?

Resistance is about 159 to 161 ohms across the board. I set the gaps with a feeler gage to 0.012-0.013" when reinstalling the coils.

And I did have the STA signal last I checked when this problem was happening before I thought it was "fixed". I'm also able to start it with the key now, since bypassing the starter contacts on the theft computer
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
So after doing some research, I found that pickup coils in the 7mge distributer are the exact same. So j looked up rebuilt or new distributors for sale because they would be cheaper, and I found a couple for like 115-125 bucks, new. Essentially, it's like paying that much for the coils, and I can just put them in the CPS housing. But that's at least an option since I can't find the coils separately.
 

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,993
Location
MKE, WI
Yup they do look pretty similar.
Though the resistance of your existing coils is right in spec.

You said you had to jumper the CPS signal to make the car run?
Does not work any other way?
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
Yup they do look pretty similar.
Though the resistance of your existing coils is right in spec.

You said you had to jumper the CPS signal to make the car run?
Does not work any other way?
Initially, all the resistance specs were on the money at the computer. Then after I checked everything else out, I jumpered the IgT green wire from the ECM straight to the igniter to bypass any wiring issues on that circuit, and she fired right up immediately. Then I ran a permanent jumper and soldered it in. Fired right up and ran great for a few days.

All I did after that is disconnect the battery to replace the steering wheel. Reconnected the battery to start her up and got the same old crank, no room movement problem as before.

Since then, I swapped the ECM and checked the grounds. No change. I made sure the timing was set perfectly. I also noticed the check engine light bulb just burned out. Tomorrow I'm going to recheck the resistance values of the CPS, swap igniters with a spare I have, then I'm going to swap the CPS with another I have. But after that I'm completely lost.
 

3p141592654

90T
Authorized Seller
Contributor
Joined
Oct 11, 2005
Messages
4,122
Location
Thousand Oaks, CA
Are you sure the MIL is burned out? Maybe you do not have power to the ECU. Also how do you set timing if it won't run?
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
Are you sure the MIL is burned out? Maybe you do not have power to the ECU. Also how do you set timing if it won't run?
The MIL being burned out is still in question. I've never seen the light not come on as usual. I meant that I set the crank and cam gears to the notch marks and aligned the CPS to proper position when installing.

I'm going to be doing to status checks today. I finished rewiring another CPS that has in-spec resistance values. So I plan on swapping that out as well just to see.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
To confirm ignition just crank and check if the tach moves. That validates the CPS and the ignitor circuits.
So far today, confirmed CPS resistance still perfect at ECM. Have constant power at BATT terminal. All fuses under hood good.

Every time I've had this issue of just cranking and not starting, the tach has stayed motionless. Which is why I've been focusing on the ignition system. I've bench tested all relays tied to the EFI system per TSRM as well. I know it has to be something small and stupid.

Edit: most notable thing that was never an issue no no power to +B or +B1. So that probably an issue. I'm gonna make a couple jumping harnesses real quick and see what all is on that circuit
 
Last edited:

3p141592654

90T
Authorized Seller
Contributor
Joined
Oct 11, 2005
Messages
4,122
Location
Thousand Oaks, CA
12V on BAT is necessary but not sufficient. When 12V is applied to IGSW (turning the key on) the ECU commands 12V on MREL which energuzes the main relay and turns on +B, +B1. Since you don't have power to +B your ECU is dead and it will never start. The MIL light not coming on is a major clue you have no power to the ECU.

Work from IGSW to MREL to the main relay to diagnose this
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
12V on BAT is necessary but not sufficient. When 12V is applied to IGSW (turning the key on) the ECU commands 12V on MREL which energuzes the main relay and turns on +B, +B1. Since you don't have power to +B your ECU is dead and it will never start. The MIL light not coming on is a major clue you have no power to the ECU.

Work from IGSW to MREL to the main relay to diagnose this
That's exactly what I gathered as well. I have the complete engine harness wiring diagram colored and laminated. Super handy. I spent like 4 hours reading, testing, and learning how this system properly works. I have definitely refreshed my brain on automotive electrical wiring lol. As soon as you said the IG s/w leads to MREL being powered out from the ECM to the relay, everything clicked. I tested continuity and operation of the EFI relay with these extension wires i made...


Essentially, I found the relay to be operational. MREL was putting 10.5v at the computer and was 10v at the relay. It was enough to power the relay and the 12v from the EFI fuse crossed over perfectly. From there is where the issue lies. In the check connector there is a B+, which is the same source that goes to the ECM from the EFI relay. There was a whopping 1.5v on that wire, which explains why the computer wasn't kicking in the CEL among other things. It also fixed itself after I got my needed measurements, allowing for voltage to pass through that circuit at 12v. So, I have a bad connection or broken wire between the EFI relay and the check connector, or at least around there. I attached my readings and locations on the paper below. My plan to fix this is to unbolt the fuse box and check out for anything obvious, but ultimately I would like to just jumper a fresh wire from the EFI relay output pin to known good section of that wire. This will save me from tearing open my harness looking for a bad wire section. But if it is loose pin in a connector, I can probably fix that. After every fix the load is directed to the next weakest link lol. At least they are handled. I will post update after tomorrow's examination and hopeful repair. Thank you guys so much!!
 
  • Like
Reactions: figgie

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,993
Location
MKE, WI
"It also fixed itself after I got my needed measurements, allowing for voltage to pass through that circuit at 12v."

What do you mean here?
What wires/connectors did you move or wiggle to do this?
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
"It also fixed itself after I got my needed measurements, allowing for voltage to pass through that circuit at 12v."

What do you mean here?
What wires/connectors did you move or wiggle to do this?
Probably fiddling with the fuse box area and constantly turning the key on and off again. When it was working properly, I made sure to shake and tug and pull on the wires and connectors at the ECM to look for any changes, but it made no difference. One of the few components I've left alone for a looooong time is that fuse box area. And I have a feeling this problem has existed here and there but was masked by the IGt signal wire issue I was having earlier. I'm gonna be working on it in just a little bit.
 

Piratetip

Far From Maddening Crowds
Staff member
Super Moderator
Authorized Seller
Joined
Dec 30, 2005
Messages
1,993
Location
MKE, WI
Sounds good.
I'm interested to hear what connection is the issue.
 

3p141592654

90T
Authorized Seller
Contributor
Joined
Oct 11, 2005
Messages
4,122
Location
Thousand Oaks, CA
Since you have the relay extended like that just measure the resistance between the relay side of B+ and the ECU end of B+ and start jiggling the harness. Places to focus would be where the harness crosses from the fise box to the engine harness, where it passes through the intake manifold and goes past the EGR valve, and also where it crosses to the firewall.

I would start with the easiest and pull connector C1 at the fuse box and confirm 12V reliably at C1. The rest of it is all in the engine harness.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
Since you have the relay extended like that just measure the resistance between the relay side of B+ and the ECU end of B+ and start jiggling the harness. Places to focus would be where the harness crosses from the fise box to the engine harness, where it passes through the intake manifold and goes past the EGR valve, and also where it crosses to the firewall.

I would start with the easiest and pull connector C1 at the fuse box and confirm 12V reliably at C1. The rest of it is all in the engine harness.
Okay it is much easier to just post the videos that I made to document my discoveries. All the little jumper harnesses and wire extenders really helped with reaching from the fuse box to the ECM. Yesterday, I left it as "working properly". When I turned the key on, I was reading the same problem of 1.3-1.4 volts on the B+ wire. This was good to allow me to diagnose this issue. As I already had the voltage readings being monitored, I figured to just test it and watch for voltage spikes. I realized I was draining my battery and the EFI Main relay was getting quite hot. So I turned the car off, disconnected the battery, and just used the wire extender for the B+ output side of the relay. This was a much better idea, so thank you.

Before I turned the car off, I was measuring the resistance between the relay connection and the check connector with the ignition hot. I was reading 3-400 ohms on that wire. And then after I turned the car off, and the wire/relay started to cool down, the resistance dropped a little to about 2-300 ohms. Still pretty high. I have printed out so much electrical shit for this car. I downloaded the TSRM for an 87 Supra and found the full EWD for an 87 Supra as well. I also have that TCCS breakdown pdf. It's a lot a crap, but it allows me to get a much better understanding how these systems work.

So, I confirmed that connector you mentioned as C1, and pin 4 is the B+ wire. I started there and gave it a shake and a wiggle and noticed the resistance started to drop and then skyrocketed to like 5-600 ohms. And then, poof, straight down to under ONE ohm. I'll let the videos do the rest of the talking, but i shook the shit out of everything to get it to act up again, and it held up. Even the ground circuit to the relay was at 70 ohms initially, and then also settled down to under 1 ohm. I kept checking the numbers as I was installing and mounting everything back in place. Still held up. The battery is drained too much now, so I can't try to start it, but I'm still debating on leaving it as is for right now, or just overriding the connector and attach a fresh chunk of wire from the relay connector to just over the engine harness side. But at least the problem is located and focused. What do you guys think? Also, everyone's help on here is the best thing ever. You guys are amazing. For real. Thank you.

Videos are short, I promise.

Video 1
Video 2
Video 3
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
Have you opened up the Fuse block where you were doing the jumping?
It should open up exposing the bottom of all those relays and fuses.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
Have you opened up the Fuse block where you were doing the jumping?
It should open up exposing the bottom of all those relays and fuses.
Yup. I had it almost all the way out. I actually expected the wires to be loose in the connector in the fuse box, but they we're good and tight. Nothing look pinched or anything. If I was to add a fresh wire jumper, I'd be starting from there. I'm gonna jump the car here in just a bit and see if she fired up.
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
I will add, that the relay gets power from one of the main fusible links and that is held in place by a bolt. Check that and verify that all those bolts are nice and tight.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
That's good to know. I forgot about that bolt. I tested functionality by turning the key ON and checking for CEL and the my safc2, which runs directly off that line as well. Both fired on beautifully. I haven't read proper battery voltage from that wire in a while, when I think about it. Sometimes with the engine running, the safc2 would be showing 11.6 or so. That means that extra resistance has been there for a while, and just now prevented operation. I don't think I've heard her run smoother. Check the videos out.

Fired right up and now prepped for setting timing

Timing is set and stable! Still think it idles high though

My question is about the higher idle. I've messed with the screw on the TB over the past month, so now I don't know where it should be.

I do think my IACV is out of whack a little. I had issues having to pump the gas pedal like it's a carb engine. I have taken it apart and cleaned and tested it for movement before. Was all within spec. But if I was to tap on it with a screwdriver while it's running, it will big down and stall sometimes. It's odd.

I've never messed with the idle screw on the Lexus AFM and I did inspect the dashpot a while back. It was doing its job. Vacuum on the gauge at idle is like 19-21 inches, so that's good. Any thoughts.
 

3p141592654

90T
Authorized Seller
Contributor
Joined
Oct 11, 2005
Messages
4,122
Location
Thousand Oaks, CA
So I 'm not sure I understand what you did to fix it. It seemed like you wiggled something and it suddenly dropped to 1 ohm. Or did I misunderstand something? Idle should be ~650 rpm hot. It takes a while to adapt. And when you shutoff the IACV should be heard clicking as it opens fully. The air bypass screw should not be adjusted ever, but too late now for that advice.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
So I 'm not sure I understand what you did to fix it. It seemed like you wiggled something and it suddenly dropped to 1 ohm. Or did I misunderstand something? Idle should be ~650 rpm hot. It takes a while to adapt. And when you shutoff the IACV should be heard clicking as it opens fully. The air bypass screw should not be adjusted ever, but too late now for that advice.
Essentially, that's what happened. The wire itself didn't appear to be broken, however, after the resistance spiked up, it shot down a ND never went back up. Even with tapping, shaking, tugging, and pulling, the resistance stayed below 1 ohm.

I'm going to listen for the IACV clicking tomorrow. The idle screw on the TB, sadly has been tweaked here and there. I wish there was a way to know the original position.
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
no need to mess with the screw in the AFM.

the idle screw on the TB only exist in the 87-89 tb. they removed it from the 89-92 tb.
that is the way to set idle speed so if it is not doing anything then you have a air leak post AFM.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
no need to mess with the screw in the AFM.

the idle screw on the TB only exist in the 87-89 tb. they removed it from the 89-92 tb.
that is the way to set idle speed so if it is not doing anything then you have a air leak post AFM.
Oh, well that's the only screw I've messed with. I've never touched the one on the AFM. So the TB one is fine to move and set the idle then? And is IACV considered bad if I don't hear it click?
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
Oh, well that's the only screw I've messed with. I've never touched the one on the AFM. So the TB one is fine to move and set the idle then? And is IACV considered bad if I don't hear it click?
that is how i adjusted the idle on my old 87...

IACV should click 3 time on power down
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
that is how i adjusted the idle on my old 87...

IACV should click 3 time on power down
Ok good. I was worried about that screw after you said something lol. And thanks man for everything. You have have been such a huge help. You and 3p.
 

3p141592654

90T
Authorized Seller
Contributor
Joined
Oct 11, 2005
Messages
4,122
Location
Thousand Oaks, CA
No, the ECU adjusts the idle speed.

That screw is a factory trim to get the IACV centered for the desired idle. It never needs to be touched. If you move the screw, the ECU will just adjust the IACV to move the idle back to where it wants it. If its not doing that then something is broken.
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
No, the ECU adjusts the idle speed.

That screw is a factory trim to get the IACV centered for the desired idle. It never needs to be touched. If you move the screw, the ECU will just adjust the IACV to move the idle back to where it wants it. If its not doing that then something is broken.
Ancedotal but i had to adjust that idle screw for a high idle rpm condition.
When i did, it was warm idling correctly (650 rpm) and the IACV was still achieving its target idle RPM when cold with out fault.

I also unplugged the TCCS to erase stored values.
 

the t3d

P B4 A
Authorized Seller
Joined
Sep 30, 2006
Messages
970
Location
Hudson, FL
No, the ECU adjusts the idle speed.

That screw is a factory trim to get the IACV centered for the desired idle. It never needs to be touched. If you move the screw, the ECU will just adjust the IACV to move the idle back to where it wants it. If its not doing that then something is broken.
I see. So I'm idling at about 1000rpm when it's warmed up, so too high. I did confirm that the IACV clicks 3 times when the car shuts off, so that's good. The battery and ECM have been plugged and unplugged a good amount of times recently. I'm sure she needs some time to settle in. Should I wait a few more drive cycles then to try and dial in the idle rpm?

Also, with that resistance issue gone, the CPS having fresh wires from the pick-ups to the ECM, the igniter signal wire replaced, and the igniter ground enhanced, she has never been so responsive. You can tell she wants to frickin move. I only have 300 miles on the fresh build, so I'm being careful. But man, shit gets me excited!
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
3p

correct me if i am incorrect but I did not think the IACV was used to keep steady state idle? It was all ignition based strategy to keep a steady idle (plus/minus x degree from base).
 

figgie

Well-Known Member
Authorized Seller
Contributor
Joined
Mar 30, 2005
Messages
5,455
Location
Shakopee, Minnesota
I see. So I'm idling at about 1000rpm when it's warmed up, so too high. I did confirm that the IACV clicks 3 times when the car shuts off, so that's good. The battery and ECM have been plugged and unplugged a good amount of times recently. I'm sure she needs some time to settle in. Should I wait a few more drive cycles then to try and dial in the idle rpm?

Also, with that resistance issue gone, the CPS having fresh wires from the pick-ups to the ECM, the igniter signal wire replaced, and the igniter ground enhanced, she has never been so responsive. You can tell she wants to frickin move. I only have 300 miles on the fresh build, so I'm being careful. But man, shit gets me excited!

careful, if you had the battery disconnected, the TCCS has had its knock values wiped so you are starting at the most aggressive timing that is programmed into the TCCS until it relearns knock value. You should be using the highest octane available in you area.