Y'all are intimidating-ly amazing! Jus say'n.

I started to type something, ask a question kinda that may or may not be helpful - but here goes... Is there anyway that that 3.45 volts could be backfeeding (don't know the correct term) from somewhere? A bad ground on the other end of the circuit? Or something. I would like to see the INSIDE of the ECU... Have you opened it, Sanchez?

 

Jay, I will have an answer for you soon.
However, the 6cu was showing 3.45v at pin 7, The 16cu shows 1.7v at Pin 7.
Ben performed a bench test on his ECU and saw 1.34 v (post #170) with the TPS disconnected. He said that when he connected the TPS the voltage at Pin 7 dropped to 0.34v(post #179) which is where the voltage should be.
No sure what's going on with my car, but eventually it will be figured out.
I have some great minds helping me to resolve this issue.
I am "BRAIN DEAD" at this point in time, so I am taking the day off from working on the car. Will resume tomorrow.

 

Absolutely the right decision, Sanchez. When the brain gets saturated, close the garage door and take time out, and let the subconscious sort it out for you!

 

Just don't allow 12yrs to pass,,, as is what happened to a LOT of these BeaUties...

 

Jay. LOL. Not happening.
ALL:
Doing some tests this morning, I realized that I have a bad TPS. My TPS has a Green, Red and Yellow pigtail.
Previously, I had tried to test resistance and I not getting any readings on my DVOM.
With the TPS connected, I have 5v on the green wire and 5v on the red wire with the throttle closed. Opening the throttle, the voltage remains the same.
I ordered a new TPS (RED) from Welshent and now I have to figure out how to adapt it to my car. No one has the adapter available.
I do not have the means to machine anything and working with the machine shops in my area is like pulling teeth.. As an example, my granddaughter's car overheated and I inquired from the machine shops in my area about machining the cylinder head (aluminum), they told me I would get it back in about 6-10 weeks. I go to one of them and they barely have any work.
Anyway back to the topic. Does anyone know how to adapt the Red TPS to the throttle pedestal?
Once I get that installed and working, I will start looking at why the ECU is not sending the ground signal to the injectors.
Is there any way of checking the ground path up to the 8 pin connector for the fuel injector harness?
The 2 resistor packs I have check out OK, both have the same impedance readings.
At the ECU harness>>>>
* I have ECU ground at Pin 1
*I have injector grounds at Pins 16, 17, 34, and 35
*I have start signal on W/R wire at Pin 26
* CTS wires U/O and Y/B check out OK
I have 3 ECUs (2 loaners 16cu) and the OEM 6cu. No joy with any of the ECUs My problem is somewhere else.
I ran a speaker wire directly from the AMP to Pin 18 and installed the ECU harness. No joy. Since I do not have a sure way to check the pulse from the Amp to Pin 18, I am looking around for another amp. I have a loaner Amp, but it is not good. The resistance readings on both the Tach output and the DWW output read the same( .09 ohms) with the condenser removed.
DO I HAVE A BAD AMP?
JUST A THOUGHT: I know I have pulse on the Tach wire because when I spray ether into the manifolds and start the car the Tach responds inside the car. Can I send the tach signal to Pin 18 via the DWW and see what happens? Bad idea?

 

Sanchez
The Red TPS can be adapted, but you do need to machine the central rod from the captan that activates it. This rod just unscrews at its flange on the capstan top.

The Bournes type (old) TPS needs a D section on the rod, and rod is machined accordingly. The Red TPS has a slot, so apart from organising a fixing plat of some sort, the end of the rod needs to be converted to a spade shape, to go into the slot. It mat also need to be shortened, dpending upon the fixing plate thickness you fab up.

New Bournes TPS which are a direct fit are available from David Manners in thr UK, if not others.

 

Please don't. It's mine.

 

Sanchez
The car's ignition is working as it runs on ether. Do not fiddle with the igntion. The problem is why the injectors are not firing fuel into the cylinders.

Have you pulled one of A1 or B1 injectors from the manifold (still attached to the rail) and looked and listened to what happens when the car is turned over on the starter?

 

No, I did not. I am using a Noid light to see if the injectors are firing. If the injectors are firing I should see the Noid light - light up. I am also using a stethoscope to listen to the injectors.
All the injectors fire when I use my test light and touch the DWW at the connector near the Amp with the key "ON".

 

The V12, PreHE and HE will start and run AT IDLE with the TPS unplugged.

Common sense and care can raise the revs, but NOT driveable obviously.

How do I know, OLD AGE, and forgetting to replug shiiit sometimes.

My TPS replacement PDF attached if its any use, MANY years ago. I stumbled (stole) an XJ40 TPS and that is still there today.

 

Sanchez, this is a repeat from an earlier post, but these are the loom/TPS connections for the later red TPS:

Loom yellow/pink goes to TPS RED = 5v volts constant ignition on
Loom yellow/white goes to TPS GREEN = signal to ECU from the wiper. It should be 0.32v throttle closed ignition on
Loom Yellow/black goes to TPS BLACK

 

Thanks Greg. That was a question I was going to ask when the TPS gets here.
"The V12, PreHE and HE will start and run AT IDLE with the TPS unplugged". (Grant)
Based on on the above statement, the Injectors should fire with or without the TPS connected.

 

Sanchez
I just wonder if there is some overlooked fault in your new injector harness. What about rigging up a test whereby you go from the loom to just ONE injector - which you have pulled from the intake and have just on its hose ?
As i understood Ben's diagram it was looking at the injector loom plug, as if looking OUT of the injector loom, at the BACK of the plug that connects to the main loom plug. Have you used OEM colours on your new injector loom, if so I could look at mine and check they are the same. But I think a one-injector test would be a good idea. You could then work back along the circuit from there.

Also, with an injector out of the intake, you could also see if fuel is spraying when you earth an injector from your DWW method.

 

Greg. Point well taken.
The EFI harness wiring connection to the plug was a question I had asked.
Since there are no markings on the plug, my question was whether the numbering in the diagram was looking at the plug towards the Injector harness or looking at the plug away from the Injector harness. I connected my harness using the numbering looking at the plug from the wire side.
I connected my home made harness to the plug where I had cut the old harness out. I made the connections as follows:
A1, A3, A5 connected to positions 2 and 6 on the plug.
A2, A4, A6 connected to positions 3 and 7 on the plug.
B1, B3, B5 connected to positions 8 and 1 on the plug.
B2, B4, B6 connected to positions 4 and 5 on the plug.
This plug is then connected to its mate coming from to loom.
Since I could not get the OEM colors for the harness, I am using;
Orange and green for A1, A3, A5 and B1, B3, B5
Pink and Grey for A2, A4, A6 and B2, B4, B6
Not that it matters about polarity but I used:
Orange and Pink to connect to the K/B wires on the plug which I labelled as Injector power.
Green and Grey connected to the Orange/?? on the plug which I labelled as ECU ground side.

Plug to Injector harness. this then connects to the other half from the loom

other side of plug going to injector harness

 

Greg. Instead of ordering the Red TPS, I opted for spending the extra $$ and purchase TPS EAC2670 which is a direct fit. The only problem with the order is that it will take 2 weeks to get to me. In the meantime, I am doing some stuff on my 88 H&E interior.
I also ordered a cheap hand held digital/analog oscilloscope to check the DWW wire.
I mentioned in one of my earlier post that I used some speaker wire run over the top of the car from the DWW connector directly to Pin 18 of the ECU.
Was that a bad idea? Should I have used a coaxial cable? I am going to order a 25ft length of shielded RCA cable to replace the DWW regardless of whether it tests good with the Oscilloscope or not.
I will follow up on the tests you recommended in Post 193 and get back to you all shortly.
Thanks.

 

Sanchez,

Speaker wire is fine.Its what I used many times to isolate an issue with ECU signals etc.

None of mine have Coax in the engine bay. I picked up that wire in the RH wheel well, just before it went through the bulkhead near the door hinge area. NO issues ever.

 

Grant. That is good to know. It will save me a few bucks. The Oscilloscope I purchased will give me some sort of results. Once it gets to me I will have to learn to use it.
I guess I will be able to see a waveform on the orange wires in the engine bay???

 

I JUST CAN'T WIN WITH THIS CAR!!!!!!
I received the Bournes TPS and installed it on the car yesterday. After fiddling with the adjustment for over an hour, I finally got it set at 0.34v (closed throttle).
Some time ago Greg warned that running the fuel pump dry was a recipe for disaster. Well, I did do a couple of tests ( maybe 3 or 4 times) just to check and see whether the pump would prime the system and turn off when the ignition was in the 'on' position and that the fuel pump would run continuously while cranking.
After installing the new TPS, I decided to put some fuel in the tank to perform the single injector test Greg suggested. The fuel pump worked and I had 35 psi at the fuel rail. I had bypassed the FPR on the A bank, ran a fuel line directly to the fuel rail and installed a 'T' fitting for a gauge on the line. However, the fuel system would not hold the fuel pressure for very long.
I turn the key 'on' pressure will build to 35 psi. Turn the key 'off' and within a couple of minutes the fuel pressure will drop to 0 psi. Turning the key 'on' and cranking the engine the fuel pressure will hold at a steady 35-38 psi, but once I turn the key 'off' the fuel pressure will slowly bleed down to 0 psi.
I was of the opinion that there is a check valve at the pressure side of the fuel pump or somewhere in the system to prevent this from happening. My XJ6 has one.
Anyway, after doing the key 'on' and cranking test a few times to check the integrity of the B bank FPR with a vacuum pump, I suddenly lost all fuel pressure.
As Greg said, the fuel pump FAILED. I guess I tested it too many times with no fuel.
I ordered a new fuel pump from Welshent and an additional fuel filter in order to get the warranty on the fuel pump. Will be here in a couple of days.
In the meantime, I will be playing with my newly acquired handheld oscilloscope to learn how to use it.
Today, I am going to look at the wiring to the CTS and ATS as recommended by Grant and will report back.
With the new TPS installed, I am still not getting the injectors to click when I go to WOT.

 

The fuel pressure is fine. There is no check valve so the pressure will drain back though the pump.

 

OK, but the pump failed completely. Will wait on new pump and never, ever again test a fuel pump dry.