KahnBB6

iTrader: (5)

Yesterday's progress...

I've had to wait to get some help from another person to do the testing/observing of the spark plugs and coils operating so maybe that will be later today or tomorrow.

In the meantime, here's where I'm at:

I checked my main TPS (throttle main) and the Sub-TPS (throttle TRAC) and discovered that I had put the TRAC TPS with the main throttle plate and harness plug (and vice versa for the TRAC connector). No wonder I was getting a CEL Code 41 telling me that something was wrong with the main TPS! Both sensors look identical and have nearly the same part numbers:

2JZ-GTE Throttle Position Sensor -- 89452-22080
2JZ-GTE Sub-Throttle Position Sensor (TRAC) -- 89452-22090

I had these two reversed in their respective places on the throttle body (although the plan is to delete the Sub-TPS for TRAC).

Upon putting the 89452-22080 sensor where it should be, the CEL Code 41 was gone with the next startup attempt.

Although I had a small hope that maybe the car would start after this. It didn't. Of course.

.....

The CEL Code 47 remains but that will be solved very soon with the appropriate resistors as detailed in post #625 on this page 42.

....

I checked the fuel return line just after the fuel pressure regulator (FPR). I put some shop rags underneath the metal pipe, pulled away the tension clamp and pulled the fuel hose back a bit. There was plenty of fuel coming out once the hose was free. I quickly put it back and re-set the tension clamp. I could have put my spare fuel hose on, pointed that into a fuel can and cranked the engine to have someone observe fuel flow into the can... but since I know there was no fuel up in the rail prior to cranking the engine for the first time the other day that suggests to me that the fuel pump is getting fuel to the rail and the FPR is returning it to the fuel tank at least.

This tells me that I need to focus on the injectors.

Again, I'll have to wait until later today or tomorrow to have help nearby to be able to check the spark plugs and coils and also listen for fuel injector ticking with my stethoscope.

....

Then as I studied the electrical schematics for the fuel injector wire paths I figured I should test the USDM 550cc injector resistor pack that I have installed.

I looked it up in the 2JZ-GTE SFI TSRM and took out my multimeter. Setting it to 200 Ohms I tested both the resistor pack in the car and my spare resistor pack. At 68F ambient temperature you're looking for a reading of 6 Ohms for it to be "good". It was 72 degrees inside and I measured 6.2-6.3 Ohms on all injector pins on both resistor packs.

So I think that is a sign that they are both in good shape...?



Also refer to SF thread: https://www.supraforums.com/forum/sh...sistor-2jz-gte!

.....

With my injector resistor pack confirmed as good that can't be the problem.

I had Driftmotion clean, flow test and re-balance my USDM 550cc low-impedance injectors some months back so I know that they are good and should have no issues.

I also had Driftmotion inspect and re-cap my USDM OBD1 2JZ-GTE ECU... so there shouldn't be any issue there either. To test the ECU requires a special harness tool according to the TSRM.

If the issue is indeed my fuel injectors not firing, this would only leave continuity of the wiring as the final thing to check.

KahnBB6

iTrader: (5)

I've had another suspicion as to why my car won't start but the more I read into the remote possibility of it the more I doubt that it could truly be an issue.

Nonetheless: After the car has sat dormant for over three months in some pretty humid weather, could the 93 octane 10% ethanol gas in my tank have gone bad to the extent that it will not achieve combustion? It's Shell gas if that makes any difference. Is that even remotely possible??

I'm still bothered by not noticing or smelling any gas on the spark plugs I pulled out so... I really don't think it's bad gasoline.

Even though the ECU is not throwing any codes now other than 47 for the Sub-Throttle TPS (TRAC TPS) I guess I should also just make sure that my crank sensor and cam sensors are all plugged in correctly. No codes thrown for those at all so that's probably not worth bothering with much either.

Tomorrow I will replace the noise suppressor next to the GTE Igniter also. I have a new one. Maybe the old one that is currently installed could have gone bad, thus causing a lack of spark...?

....

Also, even though my battery tested 12.6V with the ignition off and seems to have done just find cranking the car, I'm going to use one of those portable lithium-ion jumping devices on it next time just in case that might have anything to do with this. The battery sat for three months before I used it again and I have cranked with it a fair amount by now anyway so it could probably use a boost soon.

And I did manage to find the original manufacturer's listing for the exact model Pico 40/30A 12V automotive relay that I used to wire up my EFI 2 circuit to the TT Fuel ECU. Since it is not possible to directly purchase anything from their website I think it's okay to list here for informational purposes:

https://picocanada.com/en/view_product/925-11

I'd have bought a Tyco or Bosch relay online but I was able to find one of these Pico relays locally.

gerrb

iTrader: (34)

Craig - don't worry about engine codes for now. Your car hasn't really started and warmed up so your ECU will eventually adjust to what it sees . Codes you see right now can be temporary.

For now concentrate on whether you have spark or fuel. Spark will be the easier one to check so get that out of the way making sure there is spark. Since you have fuel coming out of the return then your fuel delivery from pump is good. No fuel on plugs / cylinders means injectors are not opening up. Since you said all your cam / crank sensors , ecu are good , then check your wiring (engine harness) . Try to trace injector wiring to ecu and their power source. The ecu simply provides the grounding for them to open up . So make sure they get the right power (voltage) by measuring how much voltage is going into the connectors.

shajbot

iTrader: (3)

Ali SC3

iTrader: (10)

This is going to sound odd, but I have heard of random code 14's which usually is ignition related turning out to be an issue with the fuel pump or fuel system.
first thing I would do is take a injector connector off and make sure you are getting the 12v on one of the terminals, and same with the coilpack connectors.

With a code 14 the ecu will shut down in a few seconds more or less (takes 6 seconds to trigger the code).
normally you can get it to start and then it will shut down real fast, so its more than just the IGF signal, its telling me the spark is not happening for whatever reason.
My hunch is that your injectors or coils are not getting 12v, but just a guess.

BTW the whole infinity scroll thing is terrible with a 40+ page thread, mods please make it go away lol.

KahnBB6

iTrader: (5)

KahnBB6

iTrader: (5)

I just had another late night brainstorm. Hopefully it's a good one and not just a foolish one.

I did not yet check the +B Ignition wire on the chassis side connector that goes into the injector resistor pack. I tested the resistor for the 6 Ohm values the TSRM specifies... but I did not test that wire with the ignition in the "ON" position.

I did this for the Ignitor module's chassis harness connector (with the ignition to ACC) but not for the resistor pack. However after last night's tests I do think the injectors are getting power. How much power I don't yet know but I feel like I heard them opening and closing (as described in the previous post).

KahnBB6

iTrader: (5)

Gerry, after the results of various testing so far I am increasingly suspicious of the fuel injectors or at least the electrical circuit governing them. I have verified SOME of it but I may well need to investigate all of it next as you suggest.

To check the continuity of all six injector wires in the wiring harness I have to run a really long electrode lead from an injector connector's negative terminal all the way into the passenger footwell to the corresponding injector pin on the ECU connector, correct? But that will only show continuity of the wires to rule out any shorts. I'd be very surprised if there were after having done all of that work. How do I verify that the ECU's own pins are completing the circuit with each firing cycle?

For voltage to the connectors I would disconnect them all and use my multimeter's positive lead on the +B/resistor wire while I ground to the battery's negative terminal and see if they are all getting +12V.

KahnBB6

iTrader: (5)

I agree with you and I've been considering this but first I would need to buy a spare set of 550cc injectors and another USDM 2JZGTE OBD1 6-speed ECU. I'd love to do this on short notice but it might be a little while waiting on both.

The injectors were sonic cleaned and flow tested by Driftmotion and I have a chart to show the results of each injector. The ECU was also worked on by Driftmotion. Inspection did not show any logic board damage inside the ECU and all the old capacitors were replaced.

KahnBB6

iTrader: (5)

^^ Yes, you and Gerry seem to be on the same page about this, Ali. I will test to make sure all the injector connectors are getting the correct +12V.

Checking for the same at the coil pack connectors also makes a lot of sense to do.

All of this is also making me strongly consider buying a new main battery. I have a lithium-ion jump starter coming in today but maybe I should consider that the battery in the car could be a weak link at this point.

But even if my not-at-all-new battery is not in perfect health... it is still strong enough to crank the engine and it's strong enough to run the power-hungry Denso TT fuel pump. That confuses me: if it were a weak battery that wasn't strong enough to output a well over +12V to all of these systems then wouldn't it feel like it were straining before and after all this cranking with no alternator to charge it?

Ali SC3

iTrader: (10)

If we were talking about an AEM I would say get a charger on that thing and make sure it is 100%.
with the stock ecu, it can start the car with hardly any juice normally, but you are trying to start an engine that has been apart and will take a little extra to start.
Those lithium will jump the car pretty well, and should help it if that is the issue but maybe grab a tender or a battery charger as likely your battery would do fine with just a charge.

I have heard of rebuilt ecu's not working, more common than one would think. I personally trust a known working original one more unless the rebuilt one is tested/comfirmed it works. I am not sure if they actually test them. If you do end up trying another ecu try it before getting it rebuilt. even if the caps are leaking it should start the car just the fueling will be off.

gerrb

iTrader: (34)

With the stock ECU , you can have less that 11v battery charge and that car should still start. It is not like the AEM as Ali have mentioned that you need the right battery charge.

It is unlikely that all your injectors are bad Craig. Have you verified that all injectors are not firing meaning all plugs / cylinders didn't get any fuel during cranking ? Got to determine that so you can localize your problem.

Voltage to the injectors is easy to check. Once ignition is on , every injector connector pin 2 should have 12v. IF they don't , then check wiring . If they do then ECU is not grounding the injector circuits to squirt fuel. It may or may not be the ECU. If it is not the ECU then a sensor that provide the ECU information to activate the injectors is bad.

Resolve / localize one thing at a time or you will be buying / replacing things that might not be needed through process of elimination. To start an engine ,you need compression , spark and fuel . Spark is easy to check . If there is spark on all plugs that means all the components related to giving spark are good which includes voltage and wiring for those components necessary to provide spark. If there is no fuel in all cylinders and it is not an Ecu or sensor/component necessary to signal the ECU to fire the injectors , then it is wiring... check those pin 2 voltages first and determine that truly there is no fuel squirted on all the cylinders when you were cranking it for a while.

I will give you an offer .. if you can't get it running , bring that car to my place since you are bringing my block anyway , hahaha , and I will get it running for you.

KahnBB6

iTrader: (5)

^^ Gerry, Ali... you both kept me on track to continue testing and ruling out each circuit connection for the injectors... and last night I did find an electrical fault. Finally.

I began by testing the USDM 550cc injector pack chassis harness connector at Pin 1 (Battery +B). I turned the ignition to "ON" just before the "START" position so that everything would be energized and put my multimeter's negative test lead to the negative battery terminal and the positive test lead to the Pin 1 of that resistor connector.

I should have seen +12V just as I did with the Ignitor's +B pin. I saw zero volts.

Going further, I turned the ignition key back to OFF for a moment, plugged the injector resistor pack back in, pulled off a couple of the injector connectors and then tested their voltage at each Pin 2 with the ignition key turned back to the "ON" position. No cranking was needed.

Again, I got zero volts for each except for one of them getting something like 1.8V (which was odd but I didn't go back to verify it again and it was probably an anomaly or I might have touched something else that was metal by accident). I got to injector #4 I think with the same result before I was seeing that it wasn't going to make any difference so long as the resistor pack's +B wire was not getting 12V in the first place.

So now I have some evidence to back up why it seems that my injectors aren't actually firing: no power to them on the positive side of the circuit. What I was hearing before with my stethoscope, despite having placed its probe right onto each injector, must have been something else inside the engine that was reverberating.

Gerry I updated you briefly over text but what I did next was this:

I know that the chassis side connector for the injector resistor pack Pin 1 gets its power from Supra IJ1-9 and so I figured I must have mis-wired at the SC IJ1 connector. I got a long test probe wire, hooked one end into resistor pack chassis connector Pin 1 and ran my multimeter into the passenger footwell. I took up the carpet and ECU cover and probed the Lexus SC body connector IJ1-3 where I made my connection to Supra IJ1-9.

I set the multimeter to Ohms and tested the wire. No continuity. Hmm.

Also, although I know we do not trust wire colors over pinouts when wiring a harness, this time I did want to find that same color wire: a dull off-white, BARELY yellow-white with occasional small silver dashes. I did not find that this was the wire color going into my SC IJ1-3 connector's pin. Maybe I soldered and shrink tubed a different color wire of the same gauge up higher up in the harness... which would require a deeper inspection (more on that below...).

Then I studied the MKIV TT wiring diagram for injectors and the SC300 Non-VVT wiring diagram for injectors.

The MKIV TT definitely has the resistor pack Pin 1 wire go all the way to Supra IJ1-9 (not sure if it gets intercepted somewhere along the way to the body plugs and spliced into another wire-- looks to be a single wire path).

The SC300 with its distributor ignition gets injector's #1 and #3 their power from SC IJ1-7... and injectors #2, #4, #5, and #6 their power from SC IJ1-3.

Gerry, you told me that SC IJ1-3 and SC IJ1-7 are basically the same and I can see that as we see in this SC300 wiring diagram:



Now aside from my need to now trace the chassis resistor/injector Pin 1 +B IJ1-9 wire into the harness at this point in order to get it into the correct body connector pin (and figure out what this other wire is that appeared to be Supra IJ1-9 when I did my body plug conversion)...

...I am a little confused on some wiring that I have done based on the cross-reference SC300 to Supra TT pinout guide from that I used when compared to your wiring harness thread pinout guide:

--The guide I used directed me to put the Supra IJ1-9 wire into SC IJ1-3. "B+ Igniton". This is a smaller gauge wire on the Supra harness with a small metal terminal. (I thought I did but since the continuity test came up negative we'll see once I can do an inspection of the harness when pulled out of the cabin and up into the engine bay to unwrap it again... sigh).

--The same guide I used directed me to put Supra IJ1-1 to SC IJ1-7. "B+ Ignition". This is a slightly thicker gauge wire with a large metal spade-style terminal like the SC fuel pump circuit's large gauge IJ1-12 wire just below it. But it's wire is not as thick as that one.

...

In your wiring thread you state (for the STOCK SC300 wiring):



And when I look at the USDM MKIV TT TSRM wiring schematic for the D1 Data Link connector I am seeing the factory setup (at least on USDM TT's) is set up for D1 Data Link Connector Pin 1 (FP) to get connected to Supra IJ1-8:




And on the SC300 IJ1 body plug the D1 Data Link pin for this (FP) signal is Pin 1 (SC IJ1-1)... which would appear to connect to the Supra IJ1-8 wire.

I think I gave you backwards information and misunderstood you yesterday, not understanding the SC's Data Link FP signal at SC IJ1-1 (and I was probably confusing that with the Supra IJ1-1 by not being specific, lol!).

I know that I have my Data Link Pin 1 FP correctly wired to Supra IJ1-8. I just messed up which "IJ1-1" I was referring to in my message which I now realize must have confused you, sorry!!

Supra IJ1-1 connected to SC IJ1-7 appears to form the TT Igniter's Pin 2 (+B) connection... and after having seen spark with a plug in one of my coils and also having tested that wire for +12V in the "ON" position I know that is working.

I just found the Supra TT USDM TSRM diagram showing that circuit (on the Supra side):





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So since, as you said, that SC IJ1-3 and SC IJ1-7 both come from the same originating circuit path... I think my SC IJ1-7 to Supra IJ1-1 soldered connection is working correctly, since I do see +12V at the Igniter and I did observe spark.

I shouldn't need to splice both of those wires to Supra IJ1-9, right?

Therefore, if my deduction tonight is on the money, my starting problem with no power to the injectors is:

--Find/trace the Resistor Pack chassis connector Pin 1 (B+) wire back through the harness to wherever it is hiding (or incorrectly inserted) and get it to its correct location at SC IJ1-3.

--Pull out the engine harness connectors into the engine bay to help in doing this if needed

--Figure out what wire is currently in the SC IJ1-3 connector socket since I observe no continuity between it and Pin 1 of the injector resistor chassis plug

....

No way am I going to attempt to remove the entire harness from the engine at this point to find one wire that was misplaced and which undoubtedly goes all the way through from one end to the other anyway. But I need room to unwrap the ECU/body plug end just enough to locate it so that's probably my task for tomorrow.

With the coolant hoses at the back of the engine being full of coolant at this time I hope I can nudge the engine harness out of there without trouble. The HCV will probably need to be unbolted and nudged forward a bit and the EVAP charcoal canister hoses will need to come off temporarily to make room to pull it out of position at the back of the engine.

Or I can test almost each and every pin on almost every connector coming in from the engine bay, lol! ... ...

gerrb

iTrader: (34)

This is your problem . No injector is firing cause none of them is getting any voltage. All of them should get their voltage on their pin 2 through that resistor pack. Pin 1 of that Resistor Pack should get its voltage from SC 1J1-7 or SC 1J1-3 (Supra 1J1-9 or IJ1-1) which comes from ignition switch the moment you turn the switch to ON (IG2) even without cranking . SC 1J1-7 and SC 1J1-3 are already internally connected on your footwell body plugs (not engine harness) not unless someone modified your wiring before.

Don't get confuse with these... they are correct . The Supra IJ1-9 is internally connected with Supra IJ1-1 . Just like the SC 1J1-3 is internally connected to SC IJ1-7. It is basically just replacing the Supra pin numbers with the SC pin numbers.


FOR NOW : find out where you connected that pin 1 of the resistor pack . It should get 12v once you turn the switch to on (IG2). At the end of the day it should be connected to SC 1J1-7 or SC IJ1-3 (It doesn't matter which one cause they are internally connected). I just prefer the IJ1-7 cause that is a bigger wire that can handle more amperage.

Ali SC3

iTrader: (10)

Glad you found it, the injector and coilpack connector test is usually the first place to start. getting 12v to the resistor pack should do the trick, hopefully you checked the coils 12v too.
Just another reason why I refuse to use resistor packs

I would almost say run another wire vs unwrapping the whole harness... if its a small portion then ok but that is alot of work.