Rescue's Official Build Thread - 88 XJS V12 Oct 12 2019
#1301
06-29-2022, 06:30 PM
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.
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.
#1303
06-29-2022, 08:30 PM
So I hooked up the a bank injector loom back to the injectors, but not the the main connector.
Turned car on, touched the wires expecting to here the injectors click... nothing... I turn the capscan and b bank clicks. Hmmm. I try again... nothing...
Turned off car.
Looked around the engine.
Go over to ignition amplifier looking at the wires / ground wire etc.
Where the ground cable goes I'm like I think that grounds probably not good. I remove the one mounting bolt. I had painted the box. So where the ground goes I sanded to bare metal. Reconnect ground ring.
Call wife. She's tired I'm tired but she know I won't sleep unless I figure something out.
the a bank injector loom is still connected to the injectors.
I pull a random one.... 2A
i tell the wife to hold the meter probe to one of the pins while i touch the wires to the main harness. 12v. Ok i tell her to go to the other pin. 12v. I'm like wtf. So turn car off. Secure all wires to the main harness. I test 6A both pins 12v. I got to 5A same I continue and all are 12v both pins. Last one plugged in is 1A. I remove it from the injector. 12v one pin. .1v other pin.
WTF I yell.
I test the others. All back to 12v and .1v
2x WTF
I connect 1A back to injector thinking something crazy.
I test 2A. Both pins 12v.
3 x WTF
I test the rest. Back to 12v both pins.
I disconnect 1A and connect a random 4A. Test 1A. Both pins have 12v.
4 x WTF
conclusion. at least one injector has to be connected for the whole bank to have 12v each pin.
When I firsted test this morning I already knew in b bank 1B was ok so I left it connected and disconnected all the other connectors. That's why all of b bank still tested 12v both pins. Or maybe it was that ground cable not properly grounded to the amplifier box.
So I'll try tomorrow (kids asleep now) to see if it will start.
I also tested each injector one at a time and could feel each one click when I turned the capstan manual. Wife worked the ignition on/off for me.
More to follow tomorrow.
Turned car on, touched the wires expecting to here the injectors click... nothing... I turn the capscan and b bank clicks. Hmmm. I try again... nothing...
Turned off car.
Looked around the engine.
Go over to ignition amplifier looking at the wires / ground wire etc.
Where the ground cable goes I'm like I think that grounds probably not good. I remove the one mounting bolt. I had painted the box. So where the ground goes I sanded to bare metal. Reconnect ground ring.
Call wife. She's tired I'm tired but she know I won't sleep unless I figure something out.
the a bank injector loom is still connected to the injectors.
I pull a random one.... 2A
i tell the wife to hold the meter probe to one of the pins while i touch the wires to the main harness. 12v. Ok i tell her to go to the other pin. 12v. I'm like wtf. So turn car off. Secure all wires to the main harness. I test 6A both pins 12v. I got to 5A same I continue and all are 12v both pins. Last one plugged in is 1A. I remove it from the injector. 12v one pin. .1v other pin.
WTF I yell.
I test the others. All back to 12v and .1v
2x WTF
I connect 1A back to injector thinking something crazy.
I test 2A. Both pins 12v.
3 x WTF
I test the rest. Back to 12v both pins.
I disconnect 1A and connect a random 4A. Test 1A. Both pins have 12v.
4 x WTF
conclusion. at least one injector has to be connected for the whole bank to have 12v each pin.
When I firsted test this morning I already knew in b bank 1B was ok so I left it connected and disconnected all the other connectors. That's why all of b bank still tested 12v both pins. Or maybe it was that ground cable not properly grounded to the amplifier box.
So I'll try tomorrow (kids asleep now) to see if it will start.
I also tested each injector one at a time and could feel each one click when I turned the capstan manual. Wife worked the ignition on/off for me.
More to follow tomorrow.
The following users liked this post:
Greg in France (06-30-2022)
#1306
06-30-2022, 10:36 AM
I did put a inline tester light and it did light up.
I wonder if i hooked my jeep up with jumper cables to the jag battery (jag battery is new and fully charged) it would give me some extra power?
Idk I'm running out of ideas and beer lol
I wonder if i hooked my jeep up with jumper cables to the jag battery (jag battery is new and fully charged) it would give me some extra power?
Idk I'm running out of ideas and beer lol
#1308
06-30-2022, 10:57 AM
#1309
06-30-2022, 11:03 AM
Senior Member
Ok ill try that stuff but what is a bell test?
I take it you are getting a click out of the injectors of both banks now ? You need one of each group connected to measure 12V on both pins as the injector completes the circuit.
#1312
06-30-2022, 12:23 PM
Not yet. I'm really leaning towards the starter. I ordered a replacement because why not. I'm gonna try one last time today to start it. If not I'll jack her up and check the starter and connectors there. Then try again tomorrow.
New starter will be here Monday (holiday tomorrow here)
New starter will be here Monday (holiday tomorrow here)
#1313
06-30-2022, 12:44 PM
Senior Member
That turnover does seem slow, make sure the engine to chassis grounds are good or the starter will find another path, many add a second ground on the starter side of the engine in addition to the one on the left side.
Did you consider a geared starter - more modern tech and major improvement on stock both for torque and reduced power consumption - stick WOSP LMS017 in your favourite search engine - not sure what's available in your neck of the woods.
Did you consider a geared starter - more modern tech and major improvement on stock both for torque and reduced power consumption - stick WOSP LMS017 in your favourite search engine - not sure what's available in your neck of the woods.
The following users liked this post:
Greg in France (07-01-2022)
#1314
06-30-2022, 01:02 PM
That turnover does seem slow, make sure the engine to chassis grounds are good or the starter will find another path, many add a second ground on the starter side of the engine in addition to the one on the left side.
Did you consider a geared starter - more modern tech and major improvement on stock both for torque and reduced power consumption - stick WOSP LMS017 in your favourite search engine - not sure what's available in your neck of the woods.
Did you consider a geared starter - more modern tech and major improvement on stock both for torque and reduced power consumption - stick WOSP LMS017 in your favourite search engine - not sure what's available in your neck of the woods.
I searched that started and nothing over here. That would be almost 500 cdn after exchange and shipping.
It did seem better with my jeep hooked up. The turnover was faster where I thought it was gonna catch.
I'm done for the day. Had enough.
Everything's closed tomorrow due to holiday so on Saturday I'll put another ground on the left hand side (engine block to chassis?)
I also pick up some starter fluid at the same time I grab a cable.
I also messaged a guy I know that lives nearby that is pretty good with jag and Landover stuff. Maybe he can swing by and hit it hard with a hammer lol
#1315
06-30-2022, 01:03 PM
'Bell Test' is a point on multimeters where it will buzz or ring if you have a complete circuit - think of it as a continuity tester.
I take it you are getting a click out of the injectors of both banks now ? You need one of each group connected to measure 12V on both pins as the injector completes the circuit.
I take it you are getting a click out of the injectors of both banks now ? You need one of each group connected to measure 12V on both pins as the injector completes the circuit.
Ah multimeter doesn't have that function of making noise. But I just grabbed a new one that does I think lol
Yes all injectors are good
#1316
06-30-2022, 01:39 PM
Senior Member
hit it hard with a hammer
On the ground I think the favourite from the engine mount on the engine side to a location on one of the subframe mounts - it is in a guide someplace - remember reading it, read it here too but not finding it right now.
One thing worth its weight on older English autos is a good multimeter, made more necessary by the age of the PVC much of which is past its sell by, connectors that are simply joining two oxide layers together, not to mention an unknown past / history of well meaning abuse. I actually went a little further and obtained a portable oscilloscope type meter but that's because I have 4 'classics' with early 80's electronics and early 80's fuel injection systems none of which get nearly enough use. Most so called mechanics today are out of their depth when it comes to diagnosis on our motors because there's no port for the laptop and a lot of the basic diag skills are being lost.
#1317
06-30-2022, 02:54 PM
That will be $10,000 please - $5 for the hammer and $9,995 for knowing what to hit with it.
On the ground I think the favourite from the engine mount on the engine side to a location on one of the subframe mounts - it is in a guide someplace - remember reading it, read it here too but not finding it right now.
One thing worth its weight on older English autos is a good multimeter, made more necessary by the age of the PVC much of which is past its sell by, connectors that are simply joining two oxide layers together, not to mention an unknown past / history of well meaning abuse. I actually went a little further and obtained a portable oscilloscope type meter but that's because I have 4 'classics' with early 80's electronics and early 80's fuel injection systems none of which get nearly enough use. Most so called mechanics today are out of their depth when it comes to diagnosis on our motors because there's no port for the laptop and a lot of the basic diag skills are being lost.
On the ground I think the favourite from the engine mount on the engine side to a location on one of the subframe mounts - it is in a guide someplace - remember reading it, read it here too but not finding it right now.
One thing worth its weight on older English autos is a good multimeter, made more necessary by the age of the PVC much of which is past its sell by, connectors that are simply joining two oxide layers together, not to mention an unknown past / history of well meaning abuse. I actually went a little further and obtained a portable oscilloscope type meter but that's because I have 4 'classics' with early 80's electronics and early 80's fuel injection systems none of which get nearly enough use. Most so called mechanics today are out of their depth when it comes to diagnosis on our motors because there's no port for the laptop and a lot of the basic diag skills are being lost.
I picked up a strap and some starter fluid as well. Will giver a shot tomorrow
#1318
06-30-2022, 08:53 PM
That will be $10,000 please - $5 for the hammer and $9,995 for knowing what to hit with it.
On the ground I think the favourite from the engine mount on the engine side to a location on one of the subframe mounts - it is in a guide someplace - remember reading it, read it here too but not finding it right now.
One thing worth its weight on older English autos is a good multimeter, made more necessary by the age of the PVC much of which is past its sell by, connectors that are simply joining two oxide layers together, not to mention an unknown past / history of well meaning abuse. I actually went a little further and obtained a portable oscilloscope type meter but that's because I have 4 'classics' with early 80's electronics and early 80's fuel injection systems none of which get nearly enough use. Most so called mechanics today are out of their depth when it comes to diagnosis on our motors because there's no port for the laptop and a lot of the basic diag skills are being lost.
On the ground I think the favourite from the engine mount on the engine side to a location on one of the subframe mounts - it is in a guide someplace - remember reading it, read it here too but not finding it right now.
One thing worth its weight on older English autos is a good multimeter, made more necessary by the age of the PVC much of which is past its sell by, connectors that are simply joining two oxide layers together, not to mention an unknown past / history of well meaning abuse. I actually went a little further and obtained a portable oscilloscope type meter but that's because I have 4 'classics' with early 80's electronics and early 80's fuel injection systems none of which get nearly enough use. Most so called mechanics today are out of their depth when it comes to diagnosis on our motors because there's no port for the laptop and a lot of the basic diag skills are being lost.
Question would I just spray the starter fluid in one intake?
#1319
07-01-2022, 07:43 AM
Senior Member
#1320
07-01-2022, 09:39 AM
Veteran Member
I agree. Slow down a bit and think things thru.
With the way the car sounds when cranking I have a feeling the plug leads may need a checking,,, coil leads as well. Perhaps the MAIN coil connectors... It's struggling to roll over a little more than I'm used to.