XJS ( X27 ) 1975 - 1996 3.6 4.0 5.3 6.0

Rescue's Official Build Thread - 88 XJS V12 Oct 12 2019

Thread Tools
 
Search this Thread
 
  #1281  
Old 06-28-2022, 09:20 PM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

So I replied to the other thread. Tps gave me wierd readings.

Yellow wire was .02 no matter what I did. Red was the only one I could adjust. After adjusting I can hear the injectors click. Still no start. Gonna spend tomorrow going through as much as the list as I can. I think the tps should be replaced. Gonna play again tomorrow with it one more time just in case.

 
  #1282  
Old 06-29-2022, 04:57 AM
Greg in France's Avatar
Veteran Member
Join Date: Jan 2012
Location: France
Posts: 13,535
Received 9,331 Likes on 5,475 Posts
Default

Originally Posted by Rescue119
ready to come off the ramps. Just need someone to help push as i dint want to start it in the garage in case i ****ed up big time.

Good news i hooked up the battery and didn't see any leaks or anything.

the radio antenna now goes up and down like intended so that's a win.

So while I'm waiting for help I do have a wiring concern.

So when I turn this switch on



The aux fan comes on. that 12" fan is loud and strong fyi. Go spal!

thoughts as I was trying to have it only come on when the compressor comes on. Or by activating that switch should the compressor be tripped?
It should not come on with the switch. If you test the compressor 12v feed, switch on, the compressor feed shold not have 12v. Let us know what you find.
But, do you have DII or DIII? It is sometime possible for the DII to take a minute or two to get itself organised before acting properly! So if you do have 12v at the compressor, switch on, it might just be that. Get the car running first.
 
  #1283  
Old 06-29-2022, 04:59 AM
Greg in France's Avatar
Veteran Member
Join Date: Jan 2012
Location: France
Posts: 13,535
Received 9,331 Likes on 5,475 Posts
Default

Originally Posted by Rescue119
So I replied to the other thread. Tps gave me wierd readings.

Yellow wire was .02 no matter what I did. Red was the only one I could adjust. After adjusting I can hear the injectors click. Still no start. Gonna spend tomorrow going through as much as the list as I can. I think the tps should be replaced. Gonna play again tomorrow with it one more time just in case.
Did you have q steady 5v at the feed wire to the TPS? If you did; then a duff TPS is likely if the output signal back to the ECU stays at 0.02.
 
  #1284  
Old 06-29-2022, 05:53 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

Originally Posted by Greg in France
It should not come on with the switch. If you test the compressor 12v feed, switch on, the compressor feed shold not have 12v. Let us know what you find.
But, do you have DII or DIII? It is sometime possible for the DII to take a minute or two to get itself organised before acting properly! So if you do have 12v at the compressor, switch on, it might just be that. Get the car running first.
D3. Ya running car is #1. That's why I didn't tidy up the wiring until it all works properly
 
  #1285  
Old 06-29-2022, 05:55 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

Originally Posted by Greg in France
Did you have q steady 5v at the feed wire to the TPS? If you did; then a duff TPS is likely if the output signal back to the ECU stays at 0.02.
I didn't check that feed from to the tps. I watch a video late last night on how to test both sides.

Whats the difference between the red / yellow / green wires?
 
  #1286  
Old 06-29-2022, 06:05 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default



So in this diagram.

red is throttle pot wiper (what does wiper mean)

Green is throttle pot position

Yellow is throttle pot ground signal.

so i should be testing green I think.





 
  #1287  
Old 06-29-2022, 06:28 AM
Greg in France's Avatar
Veteran Member
Join Date: Jan 2012
Location: France
Posts: 13,535
Received 9,331 Likes on 5,475 Posts
Default

Originally Posted by Rescue119
I didn't check that feed from to the tps. I watch a video late last night on how to test both sides.

Whats the difference between the red / yellow / green wires?
The conections should be made as follows, assuming you have the modern red coloured TPS. You may have to peel back the loom covering to be able to identify the loom wire colours as thr stripes fade badly:
  • The loom yellow/pink is connected to the TPS red wire. This loom wire carries the constant 5v from the ECU
  • The loom yellow/white is connected to the TPS green wire. This loom wire carries the signal back to the ECU to tell it the throttle position. It should be set to 0.32v throttles closed from the ECU
  • The loom yellow/black is connected to the TPS yellow wire. This loom wire is an earth.
 

Last edited by Greg in France; 06-29-2022 at 06:42 AM.
  #1288  
Old 06-29-2022, 06:30 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

Originally Posted by Greg in France
The conections should be made as follows, assuming you have the modern red coloured TPS. You may have to peel back the loom covering to be able to identify the loom wire colours as thr stripes fade badly:
  • The loom yellow/pink is connected to the TPS red wire. This loom wire carries the constant 5v from the ECU
  • The loom yellow/white is connected to the TPS green wire. This loom wire carries the signal back to the ECU to tell it the throttle position. It should be set to 0.32v throttles closed from the ECU
  • The loom yellow/black is connected to the TPS black wire. This loom wire is an earth.
No i have the black one still.


 
  #1289  
Old 06-29-2022, 06:39 AM
Greg in France's Avatar
Veteran Member
Join Date: Jan 2012
Location: France
Posts: 13,535
Received 9,331 Likes on 5,475 Posts
Default

Originally Posted by Rescue119
No i have the black one still.
Are the TPS colours the same? If so the connections will be the same.
EDIT:
I have just checked my spare engine's black TPS. The loom plug is identical, as are the colours, and are in identical positions, so the connections will be the same too. The TPS yellow wire is the one that goes to the yellow/black loom wire by the way, corrected in my post above.
 

Last edited by Greg in France; 06-29-2022 at 06:45 AM.
The following users liked this post:
Rescue119 (06-29-2022)
  #1290  
Old 06-29-2022, 06:40 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

Originally Posted by Greg in France
Are the TPS colours the same? If so the connections will be the same.
I believe so as you can replace the black with the red one with some extra hardware and no wiring change from what I've read.
 
  #1291  
Old 06-29-2022, 06:47 AM
Greg in France's Avatar
Veteran Member
Join Date: Jan 2012
Location: France
Posts: 13,535
Received 9,331 Likes on 5,475 Posts
Default

See my edited post number 1289
 
  #1292  
Old 06-29-2022, 09:37 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

so first in list i checked fuel to rail. passed

2nd is tps. like mentioned even if disconnected or not correct engine should still run yet badly.

red wire is the one that changes.... currently 0.7 volts (needs adjusting)

yellow wire is ground

green wire is constant ...currently at 4.4v (should be up to five but i read as long as its close its good/

so now i am thinking no spark. next on list

 
  #1293  
Old 06-29-2022, 09:43 AM
Thorsen's Avatar
Veteran Member
Join Date: Aug 2017
Location: Chicago
Posts: 1,075
Received 1,553 Likes on 669 Posts
Default

I always like to use a burst of starting fluid to help diagnose a fuel issue vs a spark issue. If it tries to run on starting fluid then you know the ignition is good. If it won't try to run on starting fluid I always focus on the ignition system.
 
The following users liked this post:
Greg in France (06-29-2022)
  #1294  
Old 06-29-2022, 09:57 AM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

just pulled the 6B spark plug. looked a little wet and smelled of fuel.

waiting for my wife to get home so she can crank the engine while i check for spark

im gonna check a few more things wire wise while i wait

thing is i dont have a spare spark plug


im more leaning to no spark now and trying to figure out why


 
The following 2 users liked this post by Rescue119:
Greg in France (06-29-2022), Thorsen (06-29-2022)
  #1295  
Old 06-29-2022, 01:59 PM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

just waiting for the bteer half to come home so she can be the ing switch person.

tested the CTS and it reads correctly... 2.3k ohms on a cold engine.

good news is my new air filters showed up today.

 
  #1296  
Old 06-29-2022, 03:24 PM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

so my results for todays testing.

also bought a inline spark tester

ill start at the beginning of the document:

fuel system section:

pulled fuel line - turned on ing. pump squirted fuel well.

pump works fine (replaced relay last year) works as intended

fresh gas yesterday. 10L 91 Oct with oct booster added for a little extra oompf

new fuel filter replaced a few days ago.


EFI electrical issues

I suspected this is where the issues lies

fix the TPS so now when i move the capscan i hear the injectors click. once

right now tps gets 0.7v at idle and 4.4v at full throttle. will adjust later but wont affect startup

i removed spark plug 6B. is a little wet and smells of gas.

i put spark plug back and install inline tester.

turn over and there is a spark. but engine is still struggling.

i test the CTS. test results are 2.3k ohm which is good very cold engine.

i jump the CTS anyways and no start.

I test the single ignition coil. have battery voltage, crank engine, it drops about 1.0v. no more.

i test the ohms. .70 to .80.

so i didnt test everything as i am going to have to create a long jumper to check the pins at the ECU etc.

so everything i tested passed.

so then im sitting here and im like i only tested one of the connectors in the injector loom which i rebuilt. i tested the 1B one. 12v each pin. so i skipped the rest.

well now i decided to test the all. start on the B bank. all 6 have 12v to each pin.

onto A bank. I test the first one. one pin has 12v the other pin has 0.1v. I test the other 5. all of them are one pin is 12v the other is 0.1v. and 3 of them are opposite of the other pins. 1,3,5 are same and 2,4,6 are the same.

So is this my issue. I think so. would the engine not start on only one bank lol?

I must have wired 2 parts of each section wrong. ?

thoughts while i pull out the A bank loom.
 
  #1297  
Old 06-29-2022, 03:53 PM
BenKenobi's Avatar
Senior Member
Join Date: Aug 2020
Location: UK, Glossop
Posts: 970
Received 593 Likes on 368 Posts
Default

Should it run on 6 - well if the stars align - mine would, but I don't recommend. I'd expect to see 12V both sides of the injector unless you don't have them connected same as bank B - the only time the injectors are grounded is when the ECU grounds them, the harnesses that you think are no good disconnect the injectors and check the side that is 0.1 to ground - you should not have any continuity to ground. If you identify a permanent ground do not connect the injectors they will burn out if energised too long.

Either way you do have a defect on bank A - I don't think it is polarity related since injectors are only coils and not polarised as long as each '3' are consistent I don't think it matters a whole lot.

Check the injectors for continuity - coil resistance 3 ohms or so.


 
  #1298  
Old 06-29-2022, 05:40 PM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

Originally Posted by BenKenobi
Should it run on 6 - well if the stars align - mine would, but I don't recommend. I'd expect to see 12V both sides of the injector unless you don't have them connected same as bank B - the only time the injectors are grounded is when the ECU grounds them, the harnesses that you think are no good disconnect the injectors and check the side that is 0.1 to ground - you should not have any continuity to ground. If you identify a permanent ground do not connect the injectors they will burn out if energised too long.

Either way you do have a defect on bank A - I don't think it is polarity related since injectors are only coils and not polarised as long as each '3' are consistent I don't think it matters a whole lot.

Check the injectors for continuity - coil resistance 3 ohms or so.
Bang on 3 ohms each one.
 
  #1299  
Old 06-29-2022, 05:41 PM
Rescue119's Avatar
Veteran Member
Thread Starter
Join Date: Oct 2019
Posts: 1,318
Received 597 Likes on 382 Posts
Default

So I took the loom for a bank off and went over it wire by wire. I did find one error but after the adjustment I still get the same results on all connectors in that loom. 12v one pin .1v other pin. Here is a picture of my wiring.
remember B bank is 12v both pins. I'm stumped and calling it a night
 
  #1300  
Old 06-29-2022, 06:25 PM
BenKenobi's Avatar
Senior Member
Join Date: Aug 2020
Location: UK, Glossop
Posts: 970
Received 593 Likes on 368 Posts
Default

Just be methodical and don't assume when playing with electrics, how often 'I know that is OK' has bitten me.

Resistance says the injectors are OK. Bank B is exactly how it should be.

Step 1 disconnect bank A injectors at the inner fender, then turn on the ignition, then connect the injectors at the inner fender and listen - if you hear a click there is a path to ground, you see 0.1 because you're measuring that ground potential. I'd wager that if you do have a short to ground that connecting the injectors with the ignition on will trigger a click as you connect, that's why the plugs are wet, you're probably constantly fueling on bank A.

From there it is just a process of elimination. With the injectors disconnected engine side, with fender connector connected and ignition off bell test to ground the side that is low @ 0.1, bell test not volts - there should be no path to ground. Now turn on the ignition and repeat - there should still be no path to ground. You can also test the plug by the inner wing (or fender) to ground (pins 7 and 6) - if they ring to ground disconnect the resistor pack and check again, if you still have a ground disconnect the ECU and check again - if you still have a ground there's a short between the front and the back - if you don't reconnect the ECU and see if the ground comes back, if it does the problems in the ECU.

For the sake of awareness it is super important to ensure that the resistor pack is not only fully functional but that connections to and from it are good - the engine will run without it - but not for long as it eventually fries the output transistors in the ECU.
 

Last edited by BenKenobi; 06-29-2022 at 06:27 PM.
The following users liked this post:
Greg in France (06-30-2022)


Quick Reply: Rescue's Official Build Thread - 88 XJS V12 Oct 12 2019



All times are GMT -5. The time now is 05:17 AM.