No fuel or spark, needing help big time guys

[Bigzavs]

hey guys, im still having problems with my car. right now ive got no spark and my injectors are not firing at all. I had a blown cap in my ecu, i got that replaced early last week at ATS in denton. Then i found a broken wire on my harness near the connector, it was the very far bottom right red wire on the far right ecu connector, which my friend said is ignition power to the ecu, well i re-soldered that together. and i still have nothing. i used my test light and im not getting power to the far two wires on that connector. i get power to the wires right next to them but not at the two at the far side. i also checked and ive got power to the injectors and the coils when i have the key turned. i changed out the cam position sensors and the crank position sensor, and my ignitor is good, i tested that on a friends MKIV and he started and drove on it. i also checked all my fuses and they are good as well. im stumped over it, im not really electrically inclined at all, so if you guys might know what it is please chime in, if i cant figure it out this weekend its gonna go to a shop to get whatever the problem is fixed.


thanks guys

[tissimo]

any codes?

which wires are getting power and which arnt?
http://i129.photobucket.com/albums/p227/tissimo91t/Misc/91ecupinout.jpg

[Bigzavs]

im not throwing any codes i was throwing a code 14 but im pretty sure that was because of the wire that was broken

heres the pins i was talking about
http://i67.photobucket.com/albums/h301/bigzavs/91ecupinout-1.jpg

[tissimo]

is the cel flashing or on at all? sound like the ecu isn't turning on.. I'm assuming the car ran before? if not check the EA2 connector and make sure Pin 2 and pin 5 are wired correctly.

check to make sure M-Rel (pin 3 on same coonector next to Batt) has power as well (key on of course)

[Bigzavs]

the car was running literally 5 to 10 mins before i threw the code 14, heres the thread on that

http://www.supramania.com/forums/showthread.php?t=54091&highlight=code+14

just went out and checked the the CEL is flashing with it jumpered, the M-Rel is not getting power with the key turned on

[suprastanger507mgte]

is the cel flashing or on at all? sound like the ecu isn't turning on.. I'm assuming the car ran before? if not check the EA2 connector and make sure Pin 2 and pin 5 are wired correctly.

check to make sure M-Rel (pin 3 on same coonector next to Batt) has power as well (key on of course)

Pretty sure this will solve your issue right here.

[tissimo]

do you have a volt meter? or using a test light to check for power? Try a voltmeter.. Not sure if M-rel will give enough current to light a bulb (maybe a led)

[Bigzavs]

unfortunately i dont have a volt meter, probably have to wait for a couple friends to come over saturday to get that. im just using a test light for right now

[tissimo]

if +b and +b1 arn't getting any power I'd say the Main relay isn't turning on and not giving power to the ecu.. I'm surprised that the cel is working without those powered. If M-rel has 12v but still no power at +b or +b1 then its either the wiring to it or the main relay its self. If m-rel doesn't have 12v, it might be the ecu. but you might be able to bypass that..

edit: just for shits and gigles check the efi fuse.. replace it with another 15A and give it a shot..

[Bigzavs]

well ill go try it real quick, i do know this, with the key on and not trying to crank it, the main relay is getting pretty hot, i tried swapping it out but nothing happened, ill go swap it again and change the efi fuse as well

[p5150]

I think those two wires are a constant 12v. Check your B+ pin on your check connector to ensure you are getting 12v. It is the same circuit.. http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=49

Check power supply at the 15 A EFI fuse and relay right next to the battery. Also check the connectors on the circuit. The link I posted has all the information in it.

[p5150]

based on your post it sounds like quick disconnect C1... Did you have 12v at B+ on the check connector?

[Bigzavs]

ok swapped the main relay and the efi fuse and still nothing

on the C1(thats the connector iirc) since i have a 87 harness, of the top three pins the left and the right have power, but the middle on the top and the two bottoms have no power with the key turned over

[tissimo]

ahh yea.. if Batt is getting 12v then the efi fuse is fine.. doh.. must be the relay, wiring, or the ecu

edit: in your old post you said re redid the wiring? did you mess with C1 at all? what colors are where? might be backwards there somewhere.. how did you wire C1?

[p5150]

Im talking about the check connector that you bridge T1 and TE1 to check the timing. There should be a b+ pin there. What is the voltage on it?

[p5150]

That circuit is the same that the B1 and B on the ecu pull power from. It is activated by the EFI relay. There are a lot of components that tap off of that circuit. If you have power at the check connector then you have a wire connection issue in the circuit.

[Bigzavs]

just checked the B+ with my test light and theres nothing there

[Bigzavs]

i also have power at the efi fuse

[p5150]

Ok - so that means that the B+ circuit is not getting power. That wire is connected directly to the EFI relay. There are other components on that wire as well like the o2 sensor, vsv, ISC valve

Look at connector C1 on this page: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=26

[Bigzavs]

ahh yea.. if Batt is getting 12v then the efi fuse is fine.. doh.. must be the relay, wiring, or the ecu

edit: in your old post you said re redid the wiring? did you mess with C1 at all? what colors are where? might be backwards there somewhere.. how did you wire C1?

the re-wiring i did was on the resistor pack wiring for the mkiv 550s. i dont think i touched any of the wires to the C1 connector, and the wiring was done by Dr.Tweak, and the car ran and drove with the resistor pack and mkiv injectors on for 100 miles before the problems started

[p5150]

well the C1 connector is different than the diagnostic connector. I know that on one of the pages it calls the diagnostic connector "C1" as a reference but the actual C1 connector is next to the strut tower. If you do not have power to your B+ on your diagnostic port this is the next thing up the circuit. You need to check for power on it.

[Bigzavs]

Ok - so that means that the B+ circuit is not getting power. That wire is connected directly to the EFI relay. There are other components on that wire as well like the o2 sensor, vsv, ISC valve

Look at connector C1 on this page: http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=26

what do i need to look at on it? i checked with my test light and the top right and left pins on the fusebox side of C1 have power, but the middle top and the bottom 2 pins do not have power coming out of them

[p5150]

And the injectors are on a different circuit so dont worry about those. They are powered directly off the ignition switch.

[Bigzavs]

ok, so the injectors will have power with the key on, but wont fire without the ecu working. that answers one thing i was wondering about

[p5150]

http://www.supras.nl/index.php?option=com_content&task=view&id=34&Itemid=50

OK we are making progress. I assume that you have power at pins 1 and 4 on connector C1. The link above explains their purpose.

If you have power at pins 1 and 4 but do not have power (DONT FORGET TO PLUG C1 BACK TOGETHER FIRST) at check connector B+, o2 sensor pin #2, or at the ECU (all are on the same circuit) then you have a wiring issue. I think that pin 4 should be one running to your ECU. Perhaps the power supply got intercepted somewhere and used for something else or the wire is broken.

[tissimo]

Since you dont have a volt meter to check the voltage of M-rel its hard to know if its outputting a voltage to main relay. Does the test light have a bulb or a LED?

IF LED, then you could try to jump power from Batt to M-Rel (cut going to ecu first) to jump the main relay on and power +b and +b1.. IF that is the problem, then the problem is with the ECU. I'm not sure the effects jumping this would have on it as there is something messed up internally. It might work fine, or it might fry it.. so try it if you're brave... (you can disconnect ecu and try so you dont burn up the ecu if something is wrong)

How was your alternator wired? I'm not sure how Dr. Tweak did the wiring on your C1 connector. On my buddys car I crammed the alternator and EFI wires into the C1 connector and rearranged the order as I saw fit. So Stock 7m locations MIGHT not be correct. Its hard to say what was done with the C1.


IMO everything points the the ECU as the culprit

[p5150]

I think we may have sent him into overload

[p5150]

Hey man sorry I cant help more but I have to go to bed - like I said earlier you can follow that circuit on http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=49 as pins 12 and 13 coming out of the ECU. Follow the wire all the way back to the EFI relay and right before you get there you see C1.

Check all of the other feeds off of the same circuit and look for where the wire connection is broken or re-routed.

If you rig it up another way like just running another 12v source into it your other parts that run on that circuit may not work right unless you are sure they have power.

[tissimo]

Yea I'm heading to bed as well.. Hit me up on aim tomorrow when I'm on.. will be on/off have to back and get things ready for my vacation.. might not check this board much

[Bigzavs]

lol, sorry guys my browser locked up, according to that pic of C1 i dont have a wire where number 4 is, and im only getting power to 1 and 3 of it. Dr Tweak must have it right because of it running earlier with me only touching the wiring for the resistor pack wiring, and it ran on that, im gonna call a local guy and see if i can use his spare 1J ecu (really shoulda kept my stock one) if it is the ecu ill be pissed cuz its a mines ecu, but i guess ill just send it to aaron if that comes up, thanks again for the help guys, ill keep updating as i go along if i find anything else

[Bigzavs]

also my test light is a bulb(194 i believe) and thanks for the help so far guys

[Bigzavs]

well ive possibly got a stock ecu coming over tonight, so well see how that goes

[p5150]

if B1 and B on the harness end that plugs into the ECU do NOT have power then the ECU change isnt going to help you.

If they do have power then it is an ECU issue.

If they still do NOT have power as illustrated on the first page, you need to figure out where the break in the circuit is. To do that you will need a continuity tester - a function built into most multimeters. You can get a multimeter at harbor freight tools for cheap.

[Bigzavs]

whats the easiest way to check that? just taking the harness off?

[Freshmaker]

Have you checked the 7.5A fuse by the driver side kick panel?

[Bigzavs]

yup, its fine

ive checked all the fuses inside and in the fuse box in the engine bay

[Freshmaker]

Turn the key one and check for power at each fuse. Ninja edit... I meant to say each ECU fuse. The one under the dash and the one under the hood.

Hint: You can touch the little piece of metal on the outside of a fuse :)

Or I could drive a couple hours out there and fix it for you, I work for parts ;)

[p5150]

whats the easiest way to check that? just taking the harness off?

Yeah - take the harness off of the ECU and check the pins for b and b1. Isnt that how you determined if it had power or not on the first page?

If you still dont have power at B+ on the check connector than you probably dont have any there either. It is the same circuit.

[p5150]

lol, sorry guys my browser locked up, according to that pic of C1 i dont have a wire where number 4 is, and im only getting power to 1 and 3 of it. Dr Tweak must have it right because of it running earlier with me only touching the wiring for the resistor pack wiring, and it ran on that, im gonna call a local guy and see if i can use his spare 1J ecu (really shoulda kept my stock one) if it is the ecu ill be pissed cuz its a mines ecu, but i guess ill just send it to aaron if that comes up, thanks again for the help guys, ill keep updating as i go along if i find anything else


Maybe the 88 harness doesnt have that wire for number 4 - perhaps you need to find that wire and where the break in the connection is. It should be a black/red wire.

Dont forget to check the other components (beside the B+ on the check connector) in the list that run off of the same circuit. I listed them earlier. If none of them are getting power then the power from the EFI relay is not going anywhere due to a wiring problem.

Ultimately it sounds like you will have to trace it from the output at the EFI relay and find out where the break, cut or splice in the wire is.

[Bigzavs]

im gonna take the harness completely off tomorrow, im gonna unloom it and trace the wires off the ecu connector and see if anything has happened to them

[p5150]

http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=47

Look at this page and see where EFI main relay comes out of pin #2. See how it is black/red? Now that wire should go into the C1 connector just like you have probably been looking at.

Follow that wire to each point down the line in BOTH directions and test it for current. See how it splits in both directions (up and down on the page)?

One end of the wire goes backwards to connector B1 and the circuit opening relay on pg 46 - the other end of the splice goes to the fuel pressure vsv, egr vsv, isc valve, o2 sensor (pin#2), then to the check connector (B+) on page 48, and finally the B and B1 pins on the ECU.

It should remain a black and red wire from the EFI relay all the way to the ECU. Test it at all of the points on the wire diagram that I just talked about so that you dont have to pull apart the whole harness. If it works in one place and not the other look for the break in continuity in between those components.

[Bigzavs]

ok for the O2 sensor is that pin #2 on the C1 connector? cuz i have power on the female side of the connector for that pin.

now i just gotta get a multi-meter to test for the continuity(and someone who knows how to use it)

[p5150]

ok for the O2 sensor is that pin #2 on the C1 connector? cuz i have power on the female side of the connector for that pin.

now i just gotta get a multi-meter to test for the continuity(and someone who knows how to use it)

The O2 sensor plug is next to the o2 sensor....

If C1 is disconnected, you WONT have power on the other side because it is disconnected.

When testing for power on all of those other parts you have to keep c1 connected. Does that make sense?

[p5150]

Did you look at the wire diagram? And do you have power on the black/red wire?

[Bigzavs]

ok, on my C1 the black/red wire is pin #6 and i have no power there with the key turned on

[Bigzavs]

ok i set up a hotwire coming off my spare optima going straight into the black/red wire right as it comes out of the connector underneath the fusebox under the main relay, i had power at the C1 connector, where i previously didnt, i also had power at the B+ on the diagnostic port, and i had power all the way back to the ecu, but i still have no spark whatsoever or fuel

im really stumped, but jon(gotturbos?) is over and he has a multi-meter and were gonna check some stuff, if we cant figure it out, it goes to a supra shop in denton on monday

[Freshmaker]

Have you checked for power at the ECU fuse under the hood like I asked?

If you have power at the fuse, Take out your under the hood fuse box and main relay. Touch one lead to the connector and a jumper wire to your ECU:
Check for ground at white/black. Check for continuity between Black/orange and M-rel at the ECU. Check continuity between Black/red and B+ at ECU. Check continuity between Black/yellow and Batt at ECU.

[Bigzavs]

i have power at the efi fuse, im not getting power out of the main relay tho. we checked it about 5 times.

im just taking it up to a shop in denton on monday (friend and local supra guy owns the shop, cool guy) and have them fix it, im tired of working on it right now, id rather just drive it

thanks for all the help tho guys, it saved me a job of taking the harness off.........again, i appreciate it a ton. when i get the car back ill post up what the problem with the car was

[p5150]

if you arent getting power to the main relay at all then you need to take the box off and open it up. Check the wire going into the relay and it should go back to the battery.

[Bigzavs]

ok well today was the first day we fooled with it at the shop, took less than a half hour for the guy to find some stuff and fix it, he said the ecu wasnt switching on the main relay(or something along those lines) and he bypassed the circuit and got it to switch on and all the power came back to the ecu without having to hot wire it. but the car still wont fire, im getting fuel to the rail, and im getting signals from the crank sensor and the cam sensors, but im not sparking and the injectors arent pulsing

from what he said its most likely the ecu has just taken a dump on me completely. im gonna contact aaron at driftmotion and see if its possible to get it fixed. im gonna try to get one of the guys to test it out on a friends 1J tomorrow afternoon

one other question, the last time i tested it on a car, his car started up but died a few seconds later, he has 680cc injectors on his car and my mines is tuned for the stock 370's, would his car flood out and kill itself with that much fuel difference or does this mean the ecu is still messed up?

thanks again guys

[p5150]

If he has 680s and yours are 370cc then it would dump almost twice as much fuel per injection. So yes, it would run rich.

I would check all my wires before I bought a new ECU. If one of those was wrong then maybe you have some others mixed up.

[Bigzavs]

If he has 680s and yours are 370cc then it would dump almost twice as much fuel per injection. So yes, it would run rich.

I would check all my wires before I bought a new ECU. If one of those was wrong then maybe you have some others mixed up.

but would it run so rich it would kill the motor? cuz we got his car to start on the ecu but it died out, and he guessed it was from flooding.

and no wires were swapped around from when it was running to when it stopped running.

he also did say one thing, something about my ignition power being constantly on and that it may have contributed to the ecu going out or something like that. i dont remember exactly what he said tho. ill call and ask him in the morning

[Bigzavs]

ok i tested my ecu out on my friends 1J and it started his right up, so im starting to guess its in my wiring harness somewhere.

[p5150]

told ya

[JonoTurbo]

ok i tested my ecu out on my friends 1J and it started his right up, so im starting to guess its in my wiring harness somewhere.

Just so you know, I did the exact same thing when my car wasn't starting. Took my ECU and put it in a friends car and it started up and ran for 20 minutes before we shut it off. In my car it wouldn't run for even 1 minute. ECU still turned out to be the problem.

Just saying, don't rule it out.

[Bigzavs]

ive got another mines vx-rom on its way here, should be here in a few days

monday were pulling the harness off and were gonna check it for any breaks or fried wires. hopefully ill be able to crank the ho before the weekend, i hope