Jump to content
The mkiv Supra Owners Club

Starting issue


Suprakeith
 Share

Recommended Posts

Right peeps am really could do with help and ideas to fix this issue,

I will start at the beginning.....

Have done forged na-t conversion and car was running fine but has noise from alternator as if something inside loose, so got new alternator and during fitting I didn’t notice trickle charger wires were touching battery and the alternator power cable touched body work and caused short in loom as had little bit smoke.

Checked original loom and was damaged so decided to buy new tweaked loom from USA.

Fitted new loom and car wasn’t turning over but everything else working fine so Inazone turned up and checked all fuses and relays and have 12volts where should and all earths are good, came to conclusion that could be ecu so fitted new link G4+ ecu and installed a base map.

Now when try to start car get clicking noise from the injectors but engine still not turning over,

We bridged the starter relay in fuse box and engine turned over like it should.

But still getting nothing when turn key to start car.....

 

My next idea is too remove dash and remove immobiliser from loom and check any damage to wires behind dash and try again, my thinking is as now know original ecu is damaged as was not getting any noise or anything from that when tried to start car, maybe the short has damaged immobiliser aswell as ecu.

Also used the link software on laptop and am getting zero fault codes.

 

So any ideas of what problem could be causing car not to turn over would be massive help please?

Link to comment
Share on other sites

Right peeps am really could do with help and ideas to fix this issue,

I will start at the beginning.....

Have done forged na-t conversion and car was running fine but has noise from alternator as if something inside loose, so got new alternator and during fitting I didn’t notice trickle charger wires were touching battery and the alternator power cable touched body work and caused short in loom as had little bit smoke.

Checked original loom and was damaged so decided to buy new tweaked loom from USA.

Fitted new loom and car wasn’t turning over but everything else working fine so Inazone turned up and checked all fuses and relays and have 12volts where should and all earths are good, came to conclusion that could be ecu so fitted new link G4+ ecu and installed a base map.

Now when try to start car get clicking noise from the injectors but engine still not turning over,

We bridged the starter relay in fuse box and engine turned over like it should.

But still getting nothing when turn key to start car.....

 

My next idea is too remove dash and remove immobiliser from loom and check any damage to wires behind dash and try again, my thinking is as now know original ecu is damaged as was not getting any noise or anything from that when tried to start car, maybe the short has damaged immobiliser aswell as ecu.

Also used the link software on laptop and am getting zero fault codes.

 

So any ideas of what problem could be causing car not to turn over would be massive help please?

 

Pin 3 of the 8 pin connector BA1 down by the battery caries the trigger voltage for the start relay, when the key is turned to crank you should be seeing voltage here.

 

Taken from Wilbo666

JZA80 Toyota Supra 2JZ-GE 90980-10896 Engine Loom to Body Loom Plug [bA1]

This plug is located inside the engine bay near the battery and mates with male connector 90980-10896. (BA1).

 

Pin 3

Engine ECU: STA

(Engine ECU: NSW)

Starter Motor Relay Trigger Signal

Output

The body loom side of this pin needs to be connected to the starter motor relay coil positive to turn the relay on when the ignition switch is in CRANK position (and the automatic transmission park / neutral switch is in the park / neutral position if the vehicle is equipped with an automatic transmission).

 

Manual transmission: The engine loom side of this pin is connected in the engine wiring loom to the engine ECU STA pin, the engine ECU NSW pin and pin 7 of the engine loom to body plug 90980-11469.

 

Automatic transmission: The engine loom side of this pin is connected to the automatic transmission park / neutral position switch and also the engine ECU STA pin.

 

Refer to pin 7 of body loom plug 90980-11469 for further information.

 

 

Hope that helps. Once you have established if that crancking voltage is there or not you should be able to determine whats going on pretty quickly. Presumably you can hear a relay click when you mobilise/imobilise?

 

Also, if you scroll down to the first diagram (after all the pinouts) you can see how the starter circuit is wired.

Edited by Shane (see edit history)
Link to comment
Share on other sites

Thank you for that, will give that a try. We checked voltage from fuse box to starter and signal and were both fine, will try this and hopefully will be fine plus will also confirm new loom is correct.

Not hearing any relays when arm or immobilise car but can hear the injectors and relays when try to start car

Link to comment
Share on other sites

Thank you for that, will give that a try. We checked voltage from fuse box to starter and signal and were both fine, will try this and hopefully will be fine plus will also confirm new loom is correct.

Not hearing any relays when arm or immobilise car but can hear the injectors and relays when try to start car

 

Sorry I got distracted at work and forgot to paste this in:

 

http://wilbo666.pbworks.com/w/page/41678224/2JZ-GE%20JZA80%20Supra%20Engine%20Wiring

 

So if you scroll all the way down past the pin out info to the first diagram, all the info you need to determine whats going on is there.

Link to comment
Share on other sites

Right still having problems with starting the car and looking for any other help or advice, have removed immobiliser and still no joy at all.

Am wondering could it be my ignition control module that’s gone and causing issue? I have found spare in box but think it’s from a Lexus as different part number from mine, just wondering if they are interchangeable?

Am slowly running out of ideas and what to do next, only other option I thinking is making brand new loom just to start the car and have fuel pump, starter and ignition on switches on dash

Link to comment
Share on other sites

Right still having problems with starting the car and looking for any other help or advice, have removed immobiliser and still no joy at all.

Am wondering could it be my ignition control module that’s gone and causing issue? I have found spare in box but think it’s from a Lexus as different part number from mine, just wondering if they are interchangeable?

Am slowly running out of ideas and what to do next, only other option I thinking is making brand new loom just to start the car and have fuel pump, starter and ignition on switches on dash

 

Is it cranking now, i.e. is it turning over on the key?

Link to comment
Share on other sites

check the 120amp main fuse in the fuse box. also could be the silver ignitor pack on the pass suspension top or even the coil on the drivers inner wing. usually if the battery terminals cross, the 120amp fuse blows and the ignitor too ive found

 

I have checked 120amp fuse, have got spare ignition going to try that next the parts number isn’t same as mine plus have spare coil but unsure if spare coil or ignition are any good, so if no joy may get working one from yourself just to sure as got to get her started soon

Link to comment
Share on other sites

Just tired the spare ignition module and no change, but unsure if that unit is working as been in spare box for years.

Have rechecked 120fuse and it looks fine but unsure if worth replacing.

All I am getting is sound of relays and injectors after release key from turning it too firing position.

Any other ideas or suggestions very welcome please

Link to comment
Share on other sites

Keith, use that circuit diagram systematically with multi meter or even a bulb on a bit of wire and you should be able to get it cranking pretty easily. But as a pointer, when you turn the ignition on, thats the point on the key before you hit the final crank position, you should hear both efi1 and efi2 relays click. try this first and then get back to me. Once we have established this we can move on to the next stage. I am only about 45 minutes from you but am really tied up with other stuff at the moment, working long days and often away so its not easy to come over. Possibly could come over for an hour or so one evening. I am sure we can get you a bit further without that though. So first, let me know if both, one or neither of those relays are being pulled please.

Link to comment
Share on other sites

Keith, use that circuit diagram systematically with multi meter or even a bulb on a bit of wire and you should be able to get it cranking pretty easily. But as a pointer, when you turn the ignition on, thats the point on the key before you hit the final crank position, you should hear both efi1 and efi2 relays click. try this first and then get back to me. Once we have established this we can move on to the next stage. I am only about 45 minutes from you but am really tied up with other stuff at the moment, working long days and often away so its not easy to come over. Possibly could come over for an hour or so one evening. I am sure we can get you a bit further without that though. So first, let me know if both, one or neither of those relays are being pulled please.

 

I will try that tomorrow evening and get back to you, will get misses to turn key while I listen, I did look at circuit diagram but don’t understand it that much, have gotten Inazone from forum to check everything with multimeter as he understands them more than me.

Would be massive help if one evening you were able to pop over and help and would happily pay you for your time as don’t want to put you out mate.

I am frustrated with it as have done the whole build myself more or less and one silly mistake and now can’t get her to fire up now.

Link to comment
Share on other sites

I will try that tomorrow evening and get back to you, will get misses to turn key while I listen, I did look at circuit diagram but don’t understand it that much, have gotten Inazone from forum to check everything with multimeter as he understands them more than me.

Would be massive help if one evening you were able to pop over and help and would happily pay you for your time as don’t want to put you out mate.

I am frustrated with it as have done the whole build myself more or less and one silly mistake and now can’t get her to fire up now.

 

OK, well stick a meter or even a small bulb between B+ pin on the diagnostic port and ground and when the ignition switch is in that position you should see voltage. Also, just to save a bit of time, look at pin 1 of BA3 connector when in cranking position, again between ground and that pin using a meter or small bulb. Forget getting it fired up for now, lets just concentrate on getting it cranking on the key first and then we can go from there.

Edited by Shane
Pin/plug number transposed correction (see edit history)
Link to comment
Share on other sites

OK, well stick a meter or even a small bulb between B+ pin on the diagnostic port and ground and when the ignition switch is in that position you should see voltage. Also, just to save a bit of time, look at pin 1 of BA3 connector when in cranking position, again between ground and that pin using a meter or small bulb. Forget getting it fired up for now, lets just concentrate on getting it cranking on the key first and then we can go from there.

 

Wicked thank you for help will make up small bulb circuit and give that try and let you know how get on.

Link to comment
Share on other sites

OK, well stick a meter or even a small bulb between B+ pin on the diagnostic port and ground and when the ignition switch is in that position you should see voltage. Also, just to save a bit of time, look at pin 1 of BA3 connector when in cranking position, again between ground and that pin using a meter or small bulb. Forget getting it fired up for now, lets just concentrate on getting it cranking on the key first and then we can go from there.

 

Hi Shane I tested BA3 pin 1 connector and when misses was turning key didn’t get any voltage on pin 1. Did have voltage on pin 3.

And also I haven’t got the engine diagnostic port as new loom didn’t come with one, only diagnostic port have is one under drivers side and that doesn’t have a B+ pin.

Link to comment
Share on other sites

OK well thats sort of good news for you.

 

So when you say she was turning the key, just to confirm that was all the way to the cranking position wasnt it?

 

OK do this next, pull the starter relay out and stick your test bulb/meter probe between pin 4 and pin 3 of the relay socket, turn the key to crank.

 

 

 

If there is voltage/light go to 1.

 

If there is no voltage/light go to 2.

 

1) Flip the fuse box over and push your probe into pin 2 of the back of the starter relay socket and the other probe to ground, re-assemble and put the relay back, then try again and let me know what happens. Make sure the battery is disconnected while you are doing this though, and reconnect it only after you have re-assembled.

 

 

2) Remove the probe from pin 3 and connect that to the car body and try again.

 

Also, just been thinking about the fact you have swapped looms, did the new loom come from a mannual or auto? Look at the diagram and you will see on a manual car there is a link between BC1 pin 7 and BA1 pin 3, if this isnt there it would give you the symptoms you have. I think, you are not going to see a voltage when cranking on pin 4 of the starter relay and this could well be because the loom is from an auto and you need to link out the starter inhibit circuit. You can do this simply by connecting a link from BC2 pin 3 to BC1 pin 7. Am really curious now, let me know as soon as you have tried.

Edited by Shane (see edit history)
Link to comment
Share on other sites

OK well thats sort of good news for you.

 

So when you say she was turning the key, just to confirm that was all the way to the cranking position wasnt it?

 

 

OK do this next, pull the starter relay out and stick your test bulb/meter probe between pin 4 and pin 3 of the relay socket, turn the key to crank.

 

 

 

If there is voltage/light go to 1.

 

If there is no voltage/light go to 2.

 

1) Flip the fuse box over and push your probe into pin 2 of the back of the starter relay socket and the other probe to ground, re-assemble and put the relay back, then try again and let me know what happens. Make sure the battery is disconnected while you are doing this though, and reconnect it only after you have re-assembled.

 

 

2) Remove the probe from pin 3 and connect that to the car body and try again.

 

Also, just been thinking about the fact you have swapped looms, did the new loom come from a mannual or auto? Look at the diagram and you will see on a manual car there is a link between BC1 pin 7 and BA1 pin 3, if this isnt there it would give you the symptoms you have. I think, you are not going to see a voltage when cranking on pin 4 of the starter relay and this could well be because the loom is from an auto and you need to link out the starter inhibit circuit. You can do this simply by connecting a link from BC2 pin 3 to BC1 pin 7. Am really curious now, let me know as soon as you have tried.

 

Yes she was holding key in cranking position.

And it’s a brand new loom from tweaked in USA and it’s a manual loom and will try have look tonight if weather lets up.

Also we did manage to get her cranking taking out the starter relay and bridging it with a fused wire.

I am starting to think the new loom is at fault and was also thinking could I test BA3 pin 1 to see if have continuity between that and starter motor connector?

Link to comment
Share on other sites

Yes she was holding key in cranking position.

And it’s a brand new loom from tweaked in USA and it’s a manual loom and will try have look tonight if weather lets up.

Also we did manage to get her cranking taking out the starter relay and bridging it with a fused wire.

I am starting to think the new loom is at fault and was also thinking could I test BA3 pin 1 to see if have continuity between that and starter motor connector?

 

 

Yes re BA3 pin 1, thats a good shout. OK I didnt realise you had bridged out the contacts of the starter relay. Just check for volts between pin 3 and 4 of the relay, if theres nothing, check between 4 and ground. If there is nothing you need to be tracking backwards from pin 4.

Link to comment
Share on other sites

Yes re BA3 pin 1, thats a good shout. OK I didnt realise you had bridged out the contacts of the starter relay. Just check for volts between pin 3 and 4 of the relay, if theres nothing, check between 4 and ground. If there is nothing you need to be tracking backwards from pin 4.

 

Sweet will do BA3 pin check over weekend as means removing starter motor.

When you say pins 3 & 4 guessing you mean 3 & 5 as no pin 4, just tested between 3&5 and have 12.6 volts, also got over 12.6 volts pin 3 to ground and got 0 volts pin 5 to ground.

All testing done without key in ignition.

Do I need to repeat test with misses holding key in cranking position?

Link to comment
Share on other sites

Hi Shane been chating to Cam owner of Tweak’d where got loom from in USA and h told me to back probe this tan/black wire in white plug going to body and should get 12volts on cranking.

 

image

 

Did the test and checked continuity 1st to make sure had good earth and when turned key to cranking position was getting 0volts...just thought would update thread with progress just incase you had any other ideas or theory’s

Link to comment
Share on other sites

Hi Shane been chating to Cam owner of Tweak’d where got loom from in USA and h told me to back probe this tan/black wire in white plug going to body and should get 12volts on cranking.

 

https://jza80.mkivsupra.net/imports/2019/09/108.jpg

 

Did the test and checked continuity 1st to make sure had good earth and when turned key to cranking position was getting 0volts...just thought would update thread with progress just incase you had any other ideas or theory’s

 

Try moving white plug to grey connector as seen below.

 

attachment.php?attachmentid=233368&stc=1&d=1569443641

lol.jpg

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.