V12 ECU

Talk about the E-Type Series 3
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jagwit
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#41 Re: V12 ECU

Post by jagwit » Mon Apr 27, 2020 9:39 am

Another thing Michel

When an engine is running as rich as yours, plugs can "foul" (become carbon covered, which makes a dead plug) very quickly. I'm talking minutes now!!!

Then, even if you fix the fuelling issue, the engine will not run or it will run badly, but now because of fouled plugs.

So, I'm saying that after your "drive" etc yesterday, you should now remove one or two of the plugs on each bank, and visually check them. If they are very black, media blast them clean or use new ones.

If you don't have good spark, you will be chasing ghosts all day long. Another reason to upgrade the ignition system if not done already.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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MLBS3V12
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#42 Re: V12 ECU

Post by MLBS3V12 » Mon Apr 27, 2020 12:30 pm

Hi Philip

Thank you for your kind reaction.
About your remarks,
1) I confirm that the small hose is connected on both side. However I’m wondering if I’ve not bent it during the re routing from the wiring. I’ll check this.
2) I’ll verify the one dedicated to the EFI. I do have fit a new one at the rear from the right water rail because as as you know, the E Type one stays à the front. It is the one from the Marelli ECU. I realize now that the one from the EFI, at the front from the left water rail came with the engine, probably original. I’ll check it dynamically.
3) Vacuum from the manifold connected to the rear of each regulator
4) Checked, all is ok
5) I’ve changed the left regulator as I’ve got the issue you described a few weeks ago. The diaphragm was leaking and I’ve had fuel in the vacuum hose. The brand new one is in place.
6) I’ve used the Kirby Palm book and the method he describes to set up the potentiometer @idle. Hope I ‘ve done this properly. I’ll check again.
7) I’ll look at the front spark plugs as you suggest too. Hope I do not have once again to remove all of them 

So I still have some topics to look at. hope this is one of them.
Thank you
Le chemin sera long!...

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jagwit
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#43 Re: V12 ECU

Post by jagwit » Mon Apr 27, 2020 1:28 pm

MLBS3V12 wrote:
Mon Apr 27, 2020 12:30 pm

1) I confirm that the small hose is connected on both side. However I’m wondering if I’ve not bent it during the re routing from the wiring. I’ll check this.
2) I’ll verify the one dedicated to the EFI. I do have fit a new one at the rear from the right water rail because as as you know, the E Type one stays à the front. It is the one from the Marelli ECU. I realize now that the one from the EFI, at the front from the left water rail came with the engine, probably original. I’ll check it dynamically.
6) I’ve used the Kirby Palm book and the method he describes to set up the potentiometer @idle. Hope I ‘ve done this properly. I’ll check again.
7) I’ll look at the front spark plugs as you suggest too. Hope I do not have once again to remove all of them
1) A Pinched or sharply kinked pipe could have the same effect, yes. I presume you have checked that there are no vacuum leaks on the manifolds. Those overrun valves at the front of the manifolds is always a concern. An easy way to eliminate any leak from them is to temporarily block the pipes going to the air cleaner housings....
2) Coolant sensors can vary greatly. It MUST have the correct resistance vs temp characteristics. I don't know if the EFI ECU and the Ignition ECU use the same sensors. Since the engine ECU comes from Lucas and the ignition ECU comes from Marelli, there is a very good possibility that the two sensors are not the same and that the efi sensor must be correct for the EFI ECU and the ignition sensor must be correct for the Marelli ECU.
6) OK, even if you have between 0.32 and 0.36 V on the correct wire, the question is whether this voltage is STABLE while the engine is running. The engine vibration could result in this voltage jumping around and then the acceleration enrichment will activate.
7) All I'm saying is that if the engine is running over rich, DO NOT run it for a long time - if you want to save the plugs.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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MLBS3V12
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#44 Re: V12 ECU

Post by MLBS3V12 » Wed Apr 29, 2020 5:07 pm

I though to have some test to do and finally find something....
For now on, I'm stuck with the same result.
Philip, you were right, plugs dead very quickly when there is too much fuel.
I've replaced the vaccum pipe, same result....
I had a set of injectors plugged on another rail. I've tried it, same result....
I change my EFI as here also I' ha another one, same result....
I still have measure to do on the 2 coolant sensors and the throttle potentiometer.

Philip, is the throttle valve a simple switch ?
When I turn the power on, all the injectors do a on/off. Is this normal ?
Next restauration I will try to an Electric E type! :bigrin:
Le chemin sera long!...

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jagwit
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#45 Re: V12 ECU

Post by jagwit » Wed Apr 29, 2020 5:21 pm

MLBS3V12 wrote:
Wed Apr 29, 2020 5:07 pm
Philip, is the throttle valve a simple switch ?
When I turn the power on, all the injectors do a on/off. Is this normal ?
Next restauration I will try to an Electric E type! :bigrin:
When you say "throttle valve", I presume you are referring to the throttle potentiometer? It is NOT a switch. It is a variable resistor. I have a dead one in my garage. I'll make a video and post it to youtube.

It is normal for the injectors to on/off when you turn the power on (its the EFI equivalent of jabbing the throttle on a carburettor car before commencing cranking). However, are you SURE that they turn OFF???? If they turn on an stay on, it would also explain your over rich situation.

Another test is to :
1) Disable the fuel pump;
2) turn the switch on (do not crank)
3) and then turn the throttle capstan quite vigorously. This action should result in further clicking of the injectors. If you DONT get them clicking like this, I suspect you have a wiring problem that causes the injectors to open when you switch on and stay open permanently.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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MLBS3V12
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#46 Re: V12 ECU

Post by MLBS3V12 » Wed Apr 29, 2020 5:42 pm

I' m talking about this "valve", Depending of the Jaguar litterature, it is call switch or valve:

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because engine off the resistance is not 0 but ~20 Ohm. And it opens with a vaccum.
If the engine needs 0 ohm, my probleme could be there, dont you think so ?
Le chemin sera long!...

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#47 Re: V12 ECU

Post by jagwit » Wed Apr 29, 2020 5:54 pm

Aha, the full load vacuum switch is a switch yes. I would expect it to be "0" Ohm when closed and infinity when open. I think I have a spare and will measure mine.

But anyway, no, this switch only brings about a slight enrichment of the mixture. I can not see that it can be the cause of your problems. Just disconnect one leg to eliminate its effect for now.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#48 Re: V12 ECU

Post by MLBS3V12 » Wed Apr 29, 2020 6:03 pm

On the doc from R Bywater to get an XJS engine used in the E type he indicates that this switch brings 15% more @ full throttle. If mine gives not a clear 0 , it may bring these 15% more, dont you think so ?
Le chemin sera long!...

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#49 Re: V12 ECU

Post by jagwit » Wed Apr 29, 2020 6:17 pm

I don't have a a full load vacuum switch, sorry.

The spare throttle pot I have, seems to be in perfect working order! Surprise!!
I measure 3.62 kOhm between Yellow and Green.
Between Yellow and Red, it starts at 430 Ohm and gradually goes up to 3.78 kOhm as you turn the rotor.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#50 Re: V12 ECU

Post by jagwit » Wed Apr 29, 2020 6:19 pm

MLBS3V12 wrote:
Wed Apr 29, 2020 6:03 pm
On the doc from R Bywater to get an XJS engine used in the E type he indicates that this switch brings 15% more @ full throttle. If mine gives not a clear 0 , it may bring these 15% more, dont you think so ?
One would have to measure that on a car but I don't think the 20Ohm will be a problem. That additional 15% can not account for the way your car is overfuelling.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#51 Re: V12 ECU

Post by MLBS3V12 » Wed Apr 29, 2020 6:55 pm

I ll look at the pot tomorow morning.
:thankyouyellow:
Le chemin sera long!...

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#52 Re: V12 ECU

Post by MLBS3V12 » Thu Apr 30, 2020 1:42 pm

Hi,

Ive measured the pot as you did.
Between G and Y I find 4,47K, Y and R starts at 0,65K until 3k. Not the same result. As I understand that the Red is the signal, Mine is high compare to yours. In other words at idle I've already a signal from higher rev.
I'll reduce the value by setting up another position from the pot. What do you think?
Le chemin sera long!...

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#53 Re: V12 ECU

Post by jagwit » Thu Apr 30, 2020 2:22 pm

The 4.47 does not bother me. It is not hugely different from mine.

The 0.6k also does not bother me because that value is determined by how the pot is locked to the base plate with those 3 little bolts (where the adjustment SHOULD be made).

To set the pot do as follows:
1) Disconnect the two long throttle rods from the rotor and the throttle cable;
2) remove the top section from the pedestal by removing the 4 nuts visible from above.
3) withdraw the male plug of the TPS from the female plug but only enough so you can touch the metal fingers with your multimeter probes;
4) with ignition on (fuel pump disabled), you should measure 5V between Y and G - regardless of the position of the rotor;
5) with the rotor "ear" resting against the vertical stop, you should have a VOLT reading of between 0.32 - 0.36V between Y and R. (It does not matter what the Ohms are, its now the VOLTS that matter.)
6) If you don't have that VOLTAGE on R, you must loosen those 3 screws that hold the TPS to the base plate and turn the TPS until you get that VOLT reading on R.
7) After fastening the 3 bolts of TPS, check AGAIN what the voltage is, adjust if necessary. This process can be a bit frustrating, requiring many attempts.
8) mount the whole rotor to the pedestal and fasten the 4 nuts. Check again that you have this voltage.
9) Connect throttle rods and throttle cable. Check again that you still have this voltage. Neither the throttle rods, nor the cable should open the throttles AT IDLE !!! The throttle rods should be adjusted so that BOTH throttles start to move t "exactly" the same time (I'm talking that first 0.1mm!!) and BOTH throttles should be 100% open when the pedal is floored.

In any case, I highly doubt that the incorrect setting of the TPS is the cause of your overfueling. Something else is causing that.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#54 Re: V12 ECU

Post by MLBS3V12 » Fri May 01, 2020 11:34 am

Hi,

I've changed the plugs and set the pot @0.36V. Not easy for sure. It looks like it has less fumes. But the problem is that the car is not far enough reassembled to go on the road and run enough @higher rpm. :hammerdrill:
I 'll set this topic aside for now. I'll come back later on and after been able to ride on the road to see what happen.
:thankyouyellow: Philip
We will discuss later. :salute:
Le chemin sera long!...

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#55 Re: V12 ECU

Post by MLBS3V12 » Fri May 01, 2020 12:39 pm

Still a few bits to be reassembled


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Le chemin sera long!...

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#56 Re: V12 ECU

Post by jagwit » Sat May 02, 2020 12:28 pm

Another idea....

Fit another longer pipe to the ECU vacuum port, such that its easy to apply vacuum to it with some vacuum tool (like a 60cc syringe).

Start the engine and apply vacuum with the tool.

The idea is just to see if applying the vacuum makes a difference to how the engine runs.

If doing so makes an improvement, its good news as then you can search for the reason why the engine is not sending a good vacuum signal.

If not, its bad news as then something else, is wrong.

One last question: When the engine runs, can you hear the injectors clicking? (mechanic's stethoscope or long screwdriver or wooden dowl)
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#57 Re: V12 ECU

Post by MLBS3V12 » Sun May 03, 2020 5:28 pm

Hi Philip,

I do have tested theinjectors a few weeks ago, all sound to click and squirt. I've done videos:



Le chemin sera long!...

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#58 Re: V12 ECU

Post by MLBS3V12 » Sun May 03, 2020 5:37 pm

On your question :
"One last question: When the engine runs, can you hear the injectors clicking? (mechanic's stethoscope or long screwdriver or wooden dowl)"

Yes, I've tried with a wooden dowl and I've been able to hear the several clicks done on each injectors.
As I do have a second set of 12 injectors, I ve diceded to ship them for a cleaning and a check. They are packed ready to go.

I'also tried to put a vacuum with a syring on the tube going to the ECU. Nothing change. Nothing happen.
I will open the ignition ECU to see what's going on.
Le chemin sera long!...

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#59 Re: V12 ECU

Post by jagwit » Mon May 04, 2020 2:11 pm

MLBS3V12 wrote:
Sun May 03, 2020 5:37 pm
I'also tried to put a vacuum with a syring on the tube going to the ECU. Nothing change. Nothing happen.
I will open the ignition ECU to see what's going on.
This is a positive finding. When you say "Nothing change. Nothing happen.", are you saying that when applying vacuum, the ECU is not changing the pulsewidth of the injector pulsewidths? (Because this is what SHOULD happen).

This could mean that the ECU has a problem, most likely with the manifold pressure sensor.

Just out of interest, what did you use to activate the injectors in your videos?
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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#60 Re: V12 ECU

Post by MLBS3V12 » Mon May 04, 2020 6:27 pm

I do not have the scilloscope and the frequency generator (this is what I used to emulate the EFI ECU) anymore. We ard still in quarantine. I need to wait a few days before going back to work and be able to borrow the equipments once again.

What i said is that nothing seems to happen. I will try listening the clicks at the same time I apply the vaccum.

I ve cleaned the vaccum switch. Before when it was theoretically closed I measured something close to ~20 ohms now I do have a real short circuit.

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Le chemin sera long!...

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