Read it again paying attention to jetjock.
I'll give you a hint, you're using a relay to trigger another relay. Fix the existing system.
I'll give you a hint, you're using a relay to trigger another relay. Fix the existing system.
Car not starting randomly? READ THIS (30 Amp Starter Relay Mod)
- Thread starter Idealsupra
- Start date
...That feeling you get when you lean too far back in a chair and it almost falls back and you catch it? Your first wheelie at 150MPH and you're @ 11:59 cause you kno at 12:01 youre bought?( for the non biker crowd 12:01 means you're basically scraping the Taillight on a motorcycle straight vertical up and down) unless you toggle the rear brake.....Or going down hill too fast on a tricycle and you can't sync the pedals and you see the stop sign and traffic moving and you have to decide between pavement and a Mailbox??... Have NOTHING on this thread!
ha haha....Well...I was reading this thread because I have the same problem. Like I need more problems in my life, I have acquired another Supra, an 89 NA that was given to me and are now trying to figure out what its problems are. This is how I came across this thread. Electrical troubleshooting is how I sharpened my teeth since I was a Kid and those 4 slots in the wall plate were always puzzling me so I thought a paper clip would shed more Light...and it did. Poof! The Flash and 60hz oscillation was my portal to owning a Triumph TR7, TR6, and an MGB back in Highschool and Old Polaris class Submarines qualifies me in the "Where to look next" category.
My 1st Supra is undergoing its Rebuild. Will start a Build thread soon. Just got the Crank back Friday (6m) but have a 7M crank being shipped in so I will decide which crank to use in a couple of weeks.
The newly acquired NA has this problem with NOT cranking over when you turn the key. This Thread has shed some light on how to trace the culprit down. I got it to crank over to verify the engine wasn't locked up. And it does have spark. It has been sitting so long that the fuel pump is probably rusted and locked up. But as the project progresses, I post my findings. I am not getting power to the Cold Start injector wire, (Black-blue wire) It got dark on me and I couldn't finish. Testlight, Fluke meter, and cold temperatures.....I'll chime back later...
My 1st Supra is undergoing its Rebuild. Will start a Build thread soon. Just got the Crank back Friday (6m) but have a 7M crank being shipped in so I will decide which crank to use in a couple of weeks.
The newly acquired NA has this problem with NOT cranking over when you turn the key. This Thread has shed some light on how to trace the culprit down. I got it to crank over to verify the engine wasn't locked up. And it does have spark. It has been sitting so long that the fuel pump is probably rusted and locked up. But as the project progresses, I post my findings. I am not getting power to the Cold Start injector wire, (Black-blue wire) It got dark on me and I couldn't finish. Testlight, Fluke meter, and cold temperatures.....I'll chime back later...
Lol at this whole thread.
Just delete the relay put a paper clip in the socket if you dont run a streight wire.
The relay is in series with the ignition coil.
Automatic canada supras dont even have a relay in them!
The solenoid is the starter relay technicaly because it just pushes the gear out then engages the batttery cable hooked up to it to the motor.
Adding more relays and crap is not the solution.
I wish people with high enough IQs would put more sense & positive feedback into electrical issues.
Look at the wiring diagram the Starter Relay is in series with the solenoid meaning it is adding to the load on the ignition not reducing it! remvoing it will help our cart start better and allow the ignition to last longer.
Just delete the relay put a paper clip in the socket if you dont run a streight wire.
The relay is in series with the ignition coil.
Automatic canada supras dont even have a relay in them!
The solenoid is the starter relay technicaly because it just pushes the gear out then engages the batttery cable hooked up to it to the motor.
Adding more relays and crap is not the solution.
I wish people with high enough IQs would put more sense & positive feedback into electrical issues.
Look at the wiring diagram the Starter Relay is in series with the solenoid meaning it is adding to the load on the ignition not reducing it! remvoing it will help our cart start better and allow the ignition to last longer.
The purpose of the starter relay is to reduce the voltage drop due to the clutch start sw and the the anti-theft circuit (and also the current ratings needed for those components). That is its only purpose.
It should be obvious that the circuit when working properly provides reliable and satisfactory starting as befits Toyota's flagship car 20 years ago. If you have problems, then use a voltage drop test technique to find out why you aren't getting 12V at the starter black-blue wire. This is not rocket science and does not require re-engineering a circuit that works fine if all the components are functional.
An easier to read schematic can be found here.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=038
It should be obvious that the circuit when working properly provides reliable and satisfactory starting as befits Toyota's flagship car 20 years ago. If you have problems, then use a voltage drop test technique to find out why you aren't getting 12V at the starter black-blue wire. This is not rocket science and does not require re-engineering a circuit that works fine if all the components are functional.
An easier to read schematic can be found here.
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=038
I am sorry for being rude, it was 5am, I had to edit this post:
I dont want to waste anyone heres time certainly not mine.
If that statment was true then JDM & Canadian supras would blow up melt all catch on fire and never start.
The purpose of the starter relay in the MKIII supra is to be a KILL SWITCH
The reason: if either the clutch is not pushed in (removing the positive 12VDC from the starter relay coil) or the antitheft alarm is activated(removing the ground from the starter relay coil) then the STA signal from the ignition switch will not energize the starter solenoid.
That is the only correct purpose of the starter relay in this particular car & circuit.
You will see two coils in it!
1 coil to engage the gear to the flywheel(starter motor internal solenoid)
1 coil to close the switch in the starter(starter motor internal relay) this causes the starter motor to draw all the current & voltage through the thick battery cable going to the starter from the battery
So since the starter relay (functioning as a kill switch) is in series with the starter solenoid
The only current load/drop on the ignition switch is the starter relay(kill switch) + starter solenoid(actuate the gear) + the internal stater relay(engages the thick positive battery cable to the motor).
So in conclusion to the above true and factual statement:
You can disable the relay because the fallowing facts
1 it will remove parts that go bad in our supra 1Relay 1Antitheft alarm thats a POS and can be bypassed by push starting a supra if it goes off (manuel cars) finally it removes the clutch switch.
Why should you remove a clutch switch there is a whole other thread on it it reduces wear and tear on the moving parts and it is better to start your car with the tranny in nuetral not by pushing the clutch in wearing down the master & slave cylinder & throwout/pilot bearing.
Again the anti-theft alarm sucks it should have been installed on the EFI circuite not the stater motor circuite.
The best solution is to bypass the starter relay.
Wire the supra like a canada automatic supra!
Because they dont have
1:start up issues
2:a starter relay
3:a clutch start kill
4:an anti theft alarm that doesnt work.
I dont want to waste anyone heres time certainly not mine.
Wrong want to try again?3p141592654;1540193 said:
If that statment was true then JDM & Canadian supras would blow up melt all catch on fire and never start.
The purpose of the starter relay in the MKIII supra is to be a KILL SWITCH
The reason: if either the clutch is not pushed in (removing the positive 12VDC from the starter relay coil) or the antitheft alarm is activated(removing the ground from the starter relay coil) then the STA signal from the ignition switch will not energize the starter solenoid.
That is the only correct purpose of the starter relay in this particular car & circuit.
JET I am surprised you support bad information & a guy that makes no sense about the elctronics in that statment:nono:jetjock;1540219 said:
Good link and easy, as you said if you look close at the motor in the schematic:3p141592654;1540193 said:
You will see two coils in it!
1 coil to engage the gear to the flywheel(starter motor internal solenoid)
1 coil to close the switch in the starter(starter motor internal relay) this causes the starter motor to draw all the current & voltage through the thick battery cable going to the starter from the battery
So since the starter relay (functioning as a kill switch) is in series with the starter solenoid
The only current load/drop on the ignition switch is the starter relay(kill switch) + starter solenoid(actuate the gear) + the internal stater relay(engages the thick positive battery cable to the motor).
So in conclusion to the above true and factual statement:
You can disable the relay because the fallowing facts
1 it will remove parts that go bad in our supra 1Relay 1Antitheft alarm thats a POS and can be bypassed by push starting a supra if it goes off (manuel cars) finally it removes the clutch switch.
Why should you remove a clutch switch there is a whole other thread on it it reduces wear and tear on the moving parts and it is better to start your car with the tranny in nuetral not by pushing the clutch in wearing down the master & slave cylinder & throwout/pilot bearing.
Again the anti-theft alarm sucks it should have been installed on the EFI circuite not the stater motor circuite.
The best solution is to bypass the starter relay.
Wire the supra like a canada automatic supra!
Because they dont have
1:start up issues
2:a starter relay
3:a clutch start kill
4:an anti theft alarm that doesnt work.
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Evilempire1.3JZ-GTE;1540510 said:
There are so many weak links in this circuit for failure. In my case, I am loosing voltage between the IGN switch to the B-L wire at the Starter. When I DID have time to do a little troubleshooting, and with no diagram present, I was able to get the 7mGE to crank over by jumpering 12v+ to the B-L wire on the Cold Start Injector Connector. ( 2 -wires in this connector, a green wire and a Black/blue)
I did this only to verify the starter works, and that the engine would crank over to listen for catastrophic immediate failure like rod knock, and engine seizure. So far I have not heard any abnormal noises. (just got this car and don't know why it was abandoned). Anyway, As for the starting Circuit, today I will re-do the grounds. I read 12 ohms from the battery (-) to the Engine. So I think my grounds need attention. 2nd, I will trace my voltage paths and see exactly where the voltage either drops or is non-existent. IMO, Quick fixes and patches are ok if you use your car as a DD and have to have transportation to get you to work to earn a living everyday. However, when you get time, Go back and find out why the ORIGINAL circuit has failed. True the mod works, and there are certain questions as to Why the Canadian version is almost exactly the same thing as the relay Bypass mod unless you went around the Transmission Neutral Safety switch altogether.
In my case I can hear the Starter relay Click when I try to start it, but I get NO voltage to the B-L wire. That leaves 3 things to check in the path....
1. Voltage from the IGN switch (B-W)
2. Voltage into and out of the starter relay
3. Voltage @ and out of the NSS (Neutral start Switch)
4. Starter Relay Ground which comes from the Antitheft Relay
There has to be a WEAK link in there somewhere.
That's where I live today!!
I'll hit you guys back when I get back later...
**AS a Side note, there are many ways to attack a problem...The Easy way, The hard way, and the Logical way. I use ALL of them. Sometimes the Easy Way allows you to Backtrack into the Logical way to find the Failing part or weak Link. Some people have NO electrical training at all which there is nothing wrong with that BUT by having access to information in Venues such as this, you can learn by reading how others troubleshoot and adapt their methods IF you trust their skills and way of thinking. Thinking on your own is More beneficial than someone telling you the answer in alot of cases.
I don't slam or Flame a Kat if he totally is in left field.....give a little nudge and get'em on the right path...it makes threads more informative and less Hostile as I have read throughout this Cliff Hanger.
JetJock, from what it appears and correct me if I am wrong, based on his way of thinking and his Avatar, and his Username leads me to believe he is from the Aviation world. A world where Quick Fixes and shortcuts DO NOT exist.....Or shouldn't. So his way of approaching a problem is going be waaaay different than the guy stuck on the highway trying to get home. Zero Tolerance for mistakes..
If he is from the Aviation world, his approach to problems will appear as "Brutal"..but necessary if he has anything to do with Aircraft. An Airplane can't pull off to the side and fix a problem to get home. His method of Do it right the 1st time is a MANDATORY method in aviation...Check and Double, triple check. This is just how I perceive this. I may be wrong but its My Opinion only. Very interesting an informing thread here. I like to keep things Civil and not flame or argue..Thats me.
-= BM
^The solution is easy remove the starter relay.
Put a paper clip or tiny 14 gauge jumper wire with solderless spades crimped on it from pin 2 to pin 4 where the relay used to be.
It will then be wired like a Canada Automatic supra
All this will do is disable your factory anti theft alarm (starter kill) it will still go off and make noise.
Also this will remove a clutch start kill switch. it will not remove an AUTOMATIC Park selector kill.
So if your car still wont start after this jumper and its an automatic car then the linkage is out of adjustment or the park selector switch is bad.
Put a paper clip or tiny 14 gauge jumper wire with solderless spades crimped on it from pin 2 to pin 4 where the relay used to be.
It will then be wired like a Canada Automatic supra
All this will do is disable your factory anti theft alarm (starter kill) it will still go off and make noise.
Also this will remove a clutch start kill switch. it will not remove an AUTOMATIC Park selector kill.
So if your car still wont start after this jumper and its an automatic car then the linkage is out of adjustment or the park selector switch is bad.
Plain and simple....the Canadian conversion is simpler. I didn't have time to get deep into it as I was more concerned with hearing the engine run for the 1st time...It did! Crank pulley was wobbling like a piece of clay pottery.... But the engine sounded Great once I cut all the belts off the pulley!!!
Evil, in the strict technical sense 3p is correct. As an experienced electrical engineer he may at times explain things without dumbing it down (I'm often guilty of this myself) but he is nevertheless correct and the rest of his post is also dead on: there's nothing inherently wrong with the circuit's design and it works perfectly if everything is functioning as it's supposed to. If something isn't it should be repaired properly, no different than any other repair done on the car. That has been my point all along.
Crappy alarm? Clutch switch? Starter relay? In 22 years I never had a problem of any kind with the factory alarm or starting circuit. However if I had I would have repaired it properly *after* determining exactly what the root cause was. You're implying the relay is always at fault. It's not and defeating it willy-nilly without knowing it's the culprit is akin to throwing parts at the problem.
Furthermore, should *proper* diagnostic technique reveal the relay to be at fault, it should not be defeated with a paper clip. Good grief. No wonder 98% of these cars I've seen are total POS. Fix it properly! Your approach is no different than doing the mod this thread was based on.
BM: Yes, I make my living in the aviation industry. Prior to that I spent many years as a machine design and automation engineer. One does what one must after a breakdown occurs but in the final analysis there's only one way to do things and that's right. Period. It's what separates professionals from the wannabes.
Crappy alarm? Clutch switch? Starter relay? In 22 years I never had a problem of any kind with the factory alarm or starting circuit. However if I had I would have repaired it properly *after* determining exactly what the root cause was. You're implying the relay is always at fault. It's not and defeating it willy-nilly without knowing it's the culprit is akin to throwing parts at the problem.
Furthermore, should *proper* diagnostic technique reveal the relay to be at fault, it should not be defeated with a paper clip. Good grief. No wonder 98% of these cars I've seen are total POS. Fix it properly! Your approach is no different than doing the mod this thread was based on.
BM: Yes, I make my living in the aviation industry. Prior to that I spent many years as a machine design and automation engineer. One does what one must after a breakdown occurs but in the final analysis there's only one way to do things and that's right. Period. It's what separates professionals from the wannabes.
Dear JET again the starter relay is in series directly between STA IGN SW & the solenoid please read the schematic.
This is fact.
Remember Ω's LAW basics
Here is a series circuite
The current going through R1 is the same in R2 and is the same in R3
If you break the circuite anywhere between V to R1, R1 to R2, R2-R3 to place an ampmeter you will get the same current reading between any component.
Look now at the starter relay the coil power runs off of the same wire going through the ignition sw that feeds the starter solenoid. Meaning even if the relay was not there the same current would go through the ignition switch but even less because the starter relay coil draws current also because the coil of the starter relay is in parallel to the starter solenoid circuite.
Here is the same schematic drawn to mathmatics you can verify the two then tell me how I am wrong? With the correct version?
Again the purpose of starter relay in the supra is to act in the behalf of two small switches to open the circuite,
Again you can push start a supra with the anti theft alarm going off.
Again if you start a manuel supra by engaging the clutch instead of starting the car with the transmission in nuetral you are adding to wear. So I stick by the facts and wire my car simple and using the canada model and schematic.
I did the same with my fog lights because nothing is wrong with factory I just perfer to wire my car simpler and fallow the canadain electrical because it haves better options.
I think you guys are all believing that the voltage drop and current draw of the motor goes through only the relay because you believe either the #2 contact wire of the starter relay is wired direct to the battery and not through the small wire going to the ignition switch or you beleive that wiring it the canadian style haves all the current of even the starter motor going through the ignition switch this is a fallacy your mixing it up with other car schematics and not paying attention.
Please stick to the subject and reply to the facts as I have.
Not what factory options are good or bad or divert to some other scenerial that toyota quality is good etc.
Awnser the fact JET the canada supras dont have a starter relay factory and have no issue at all with out it installed and that is a factory option.
This is fact.
Remember Ω's LAW basics
Here is a series circuite
The current going through R1 is the same in R2 and is the same in R3
If you break the circuite anywhere between V to R1, R1 to R2, R2-R3 to place an ampmeter you will get the same current reading between any component.
Look now at the starter relay the coil power runs off of the same wire going through the ignition sw that feeds the starter solenoid. Meaning even if the relay was not there the same current would go through the ignition switch but even less because the starter relay coil draws current also because the coil of the starter relay is in parallel to the starter solenoid circuite.
Here is the same schematic drawn to mathmatics you can verify the two then tell me how I am wrong? With the correct version?
Again the purpose of starter relay in the supra is to act in the behalf of two small switches to open the circuite,
Again you can push start a supra with the anti theft alarm going off.
Again if you start a manuel supra by engaging the clutch instead of starting the car with the transmission in nuetral you are adding to wear. So I stick by the facts and wire my car simple and using the canada model and schematic.
I did the same with my fog lights because nothing is wrong with factory I just perfer to wire my car simpler and fallow the canadain electrical because it haves better options.
I think you guys are all believing that the voltage drop and current draw of the motor goes through only the relay because you believe either the #2 contact wire of the starter relay is wired direct to the battery and not through the small wire going to the ignition switch or you beleive that wiring it the canadian style haves all the current of even the starter motor going through the ignition switch this is a fallacy your mixing it up with other car schematics and not paying attention.
Please stick to the subject and reply to the facts as I have.
Not what factory options are good or bad or divert to some other scenerial that toyota quality is good etc.
Awnser the fact JET the canada supras dont have a starter relay factory and have no issue at all with out it installed and that is a factory option.
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Thanks for the lesson. All I'm going to say is I applaud your effort to learn this stuff and hope it continues. One area to focus on is how the starter works...
3tc power;1493573 said:
Oh no watch out, if making statements based on fact & truth someone will lash out emotionaly calling people idiots from other peoples quotes and say you need to learn more about electronics with out any knowledge of background or education lets attack the truth or fact by calling people un-knowledgable.
:nono:
OK JET I will play, how does the starter work that you dont think we understand :dunno:
I have worked on starters & starting circuites on
Cars
Jets
Helicopters
Desiel Locomotives
Is there something I missed?
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Good posts! Yesterday I did some troubleshooting and here are my findings. I hit a dead end because I could not get under the car to finish my shakedown on where the voltage is stopped. I found 12.8v on the B-W wire coming out of the IGN switch harness going to the starter relay. With the Starter relay removed I found the same. I also found the same voltage reading on the Contact side (2) terminal of the relay plug. Plugged relay back into JB, heard it click. Voltage coming out of relay (Pulled in) was 12.5v and on the relay Coil. So I am losing .3 volts in this junction. I couldn't get under the car to read the signal at the Neutral switch because I didn't have a Jack. Since my arms are like tree trunks, I couldn't get down in there to pull the wires up by the starter from under the hood area.
So from what information I did manage to gather, I need to measure the voltage at the NSS, and out of it to determine if I do have a bad Neutral switch or not, Or if in fact this is where the path ends. I do not get any voltage on the B-L wire that powers the starter solenoid and the cold start injector circuit BUT...By using a Pushbutton switch jumpered from the battery to the B-L wire on the CS injector connector, the car cranks over and starts (with Engine crack (Starter fluid)). FP is shot and shorted out. I'll tackle the fuel system later.
So my focus was then put on the crankshaft pulley (Unrelated to starting problem) where I needed to see if this wobbly pulley has mauled the Crankshaft Key-way etc. and it has. Significant wear on the crank and pulley which crumbled and fell apart cause the rubber has deteriorated. Not sure if a replacement pulley will wobble or not. Pretty sure it will since the Key-way slot is wallowed out a bit and the shaft is probably eccentricated and not round. We'll see. I'll post pics in my build thread later. But my electrical TS is inconclusive so far.
@ Evil~ Great post man.
@ Jet~ Machine design and automation...Impressive. That's also my background, Application Engineering with Servo drives, PLC's and all that madness. I went from Nuke Submarines to industrial automation. Now IT. No more 1's and Zero's. Much more fun... Anyway, I'll touch back when I have more information to share on my starting issue. Hopefully we can solve this with some actual hard core voltage path tracing / readings. I'll take the drawings and post voltage at all the key points in the drawings. Later Gents.
-=BM
So from what information I did manage to gather, I need to measure the voltage at the NSS, and out of it to determine if I do have a bad Neutral switch or not, Or if in fact this is where the path ends. I do not get any voltage on the B-L wire that powers the starter solenoid and the cold start injector circuit BUT...By using a Pushbutton switch jumpered from the battery to the B-L wire on the CS injector connector, the car cranks over and starts (with Engine crack (Starter fluid)). FP is shot and shorted out. I'll tackle the fuel system later.
So my focus was then put on the crankshaft pulley (Unrelated to starting problem) where I needed to see if this wobbly pulley has mauled the Crankshaft Key-way etc. and it has. Significant wear on the crank and pulley which crumbled and fell apart cause the rubber has deteriorated. Not sure if a replacement pulley will wobble or not. Pretty sure it will since the Key-way slot is wallowed out a bit and the shaft is probably eccentricated and not round. We'll see. I'll post pics in my build thread later. But my electrical TS is inconclusive so far.
@ Evil~ Great post man.
@ Jet~ Machine design and automation...Impressive. That's also my background, Application Engineering with Servo drives, PLC's and all that madness. I went from Nuke Submarines to industrial automation. Now IT. No more 1's and Zero's. Much more fun... Anyway, I'll touch back when I have more information to share on my starting issue. Hopefully we can solve this with some actual hard core voltage path tracing / readings. I'll take the drawings and post voltage at all the key points in the drawings. Later Gents.
-=BM
Calm down Evil, JJ' signature was not targeted to you. I believe I am well qualified to understand the intricacies of the starting circuit schematic having a PhD in Electrical Engineering from a top tech university in the USA and over 75 peer reviewed publications and 6 patents, etc.
Yes, it is true that the starter relay does not reduce the current flowing through the ignition switch and circuit. The basic starter circuit is a carryover from the mk2 Supra, and relies only on the relay built into the starter itself.
In markets where there is no theft alarm, or need for the clutch interlock, the relay is not needed and is omitted (eg Canadian market where theft alarm was not offered).
For markets that include the theft alarm and/or clutch interlock the relay is added. This is because both those enhancements would require the starter circuit to pass through additional wiring, connectors and switches to reach the alarm ECU and clutch switch causing additional voltage drop and also requiring higher current handling for those components compared to the case where no relay was used. This was discussed previously.
I have yet to run across a starter relay that had problems. Mine is 20+ years old and works fine. Why remove it at all? That's the part I don't get. Even if the alarm offers minimal protection, it still costs a thief some time to defeat so leave it in. Push starting a MK3 by yourself is no easy feat unless you happen to be at the top of a hill, and if you have an automatic forget it. To defeat the clutch interlock just jumper the switch then the alarm remains functional.
Yes, it is true that the starter relay does not reduce the current flowing through the ignition switch and circuit. The basic starter circuit is a carryover from the mk2 Supra, and relies only on the relay built into the starter itself.
In markets where there is no theft alarm, or need for the clutch interlock, the relay is not needed and is omitted (eg Canadian market where theft alarm was not offered).
For markets that include the theft alarm and/or clutch interlock the relay is added. This is because both those enhancements would require the starter circuit to pass through additional wiring, connectors and switches to reach the alarm ECU and clutch switch causing additional voltage drop and also requiring higher current handling for those components compared to the case where no relay was used. This was discussed previously.
I have yet to run across a starter relay that had problems. Mine is 20+ years old and works fine. Why remove it at all? That's the part I don't get. Even if the alarm offers minimal protection, it still costs a thief some time to defeat so leave it in. Push starting a MK3 by yourself is no easy feat unless you happen to be at the top of a hill, and if you have an automatic forget it. To defeat the clutch interlock just jumper the switch then the alarm remains functional.
I would verify with the relay inplace you have the ~12.5v on pin 4 at the relay by lifting the component or stabing it from the back.Bruno Molly;1542355 said:
to be sure the contact in the relay is good takes a second to do.
If you have an automatic there is a couple things it can be
Nuetral start switch haves corrosion on the contacts of it.
The Automatic linkage can be off adjustment.
Heat rotted the switch up wires broken off.
Since the car will turn over by bypassing the switch & relay contact
That eliminates corrosion on the battery cables or that the battery cables are loose.
My appologies for the bantering earlier.
I am currently installing a SC400 1UZ in my 1998 4runner.
Project is going smooth and working out perfect.
Does anyone have the newer supra or sc400 Fuel Pump ECU internal schematic? or know how the DL signal works on it thanks.
I hate to revive this thread but i though id post my experience. I was considering doing this and after reading Jetjocks and 3p's post i decided to give their advice/hints a try. I have a 1988 Toyota EWD for my car however i do not know how to read it. However my dad does and he explained to me how the how system works. He established my relay was working as was my nuetral start switch. We checked the ignitor and coils. Finally i asked about the ground specifically the ones on the intake manifold. I pulled off the grounds and noticed they were covered in oil and were quite dirty. I took some sandpaper to it cleaned it up, cleaned the area (left over from my valve cover leak) and put it all back. The car so far has been starting just like it should and i would even have to say it idles better. Was this the cause of my problem? I dont know but i just wanted to let others know its worthwhile checking the grounds.
Sorry, assuming you had the typical symptom of click-no-crank the manifold grounds aren't related. A crank-no-start would be a different story altogether...