Progress Update.
We have identified the major problem.
The fuel injectors are all stuck. All 12, it appears.

I recommend a test method using an LED lamp across the leads of one fuel injector..
I used a 6 Volt LED, which I use to replace radio illumination lamps when I repair old car radios.
You disconnect the fuel injector leads form one Injector, (We used #1 from right bank front).
Then you connect the LED across the injector leads.
Disconnect +V from the coil. .
Then turn on the ignition. You will see the LED light once when you turn on the ignition.
Then engage the starter and you will will see the LED flash each time the distributor goes around the right bank trigger.
This means the trigger board is working and the signal back to the ECU is good.
(BTW, we are using the original 4 wire trigger board. Your statement about not seeing the 4 wire boards fail is still true.)
It also means the ECU is sending the signals to the power Amplifier and the power amp is sending pulses to the injectors.

Next we tested the Throttle switch by turn the throttle manually.
The LED at the injector wires goes crazy with pulses.
That's good news.

The bad news was there is not a single click at the injectors.

We removed the first injector. This is a major task due the fuel rail an all other sorts things in the way.
The injector did not move and is not opened by a pulse with test leads and a battery.
We configured a spray nozzle from fuel hose and the top of a plastic squeeze bottle to fit the straw of a can of cleaner.
We soaked the injector inside for 30 minutes with (GUM OUT) carb and injector cleaner.
We then physically moved the injector "pintle" gently by hand urging it up and down until it opened.
It finally released we had a nice fan shaped spray from the injector using the spray can pressure..
Several sprays later we tested the injector with an electrical pulse and it worked.

The good news is one injector works. The bad news is this is a V12, eleven to go.

The second fuel injector did not take as long to un-stick. We have two done.
We plan to finish all twelve injectors and the retest them all next week.

1. Can you tell me what the ohm measurement of the injector should be? We measure 5.2 ohms.
2. Do you follow recommendations and always replace the o-rings?
3. Any other advice on cleaning injectors?

Best Regards,
Denny O

 

Great work. Replace ALL the rubber components concerning the injectors and the small basket filters in the inlet to the injector.

 

As Greg has said.

The lower square section seal, the one IN the Inlet manifold is the priority one to replace, as the thing will suck Vac llke crazy from a dud one of those.

The larger upper ones are just an insulator, and rarely give issues.

I reckon 48 beers is in your future, as in 2 per Injector.

A very LONG time ago, I made a soaker with a coffee jar, drilled a hole in the plastic lid, so the Injector was a TIGHT push fit. Filled the jar with standard Paint Thinners, screwed the lid on, and left it for an hour or 2, as in 2 beers.

Dried it off, hit with the 12V, and 100% spray.

OK, someone more impatient than me would make something more elaborate to take all 12, etc etc. I have TIME on my side, the coffee jar was FREE, and sitting there, and the beers is a GOOD incentive to SLOW down, surely you agree??

I like the LED test, makes the guess work obsolete.

 

We are finally back at getting the 1978 Jaguar started.
The 48 beer delay was brutal.
We tired to get all 12 fuel injectors to work evenly.
Six cleaned up with a nice spray. Six did not spray, they just dibble.
We put them aside and purchased new replacement injectors. $500 ouch!
They come with short hose attached and fit well.
We bought all 12 so they would all be the same spray and volume, etc.
We have new seals installed.
The fuel rail is cleaned and reinstalled.
Pending install of new Fuel filter we will attempt a start this week.

Three questions:
1. Anything we should watch for/adjust with new injectors?
2. We know the fuel pump runs for two seconds and the engine runs on cold start.
What will restart the fuel pump after the cold start?
3. We know the trigger switch was working from a lamp test to the amplifier.
However, we also purchased a new trigger switch and rotor and installed it.
The trigger switch fits fine. However the new rotor will not go on the distributor shaft easily.
The old rotor fits nicely and goes on and off with a good fit.
Is there a difference in rotors? Can we use the old rotor?
Regards,
Denny O


.

 

Denny,

Answered in order.

1) Nothing.
2) The pulse signal from the trigger board does that, you have nothing to do.That restart is instant, and nothing to with the cold starts.
3) Another crap aftermarket item, getting rather common. Either CAREFULLY file the hole in the rotor just a tad, to ease the push, or do what I did, OLD rotor. Dont mess with the dizzy shaft, "coz ya cannot put back what ya take off", and the next rotor may then be too loose.

Good luck.

 

The news is good, but some questions.

All 12 new fuel injectors are installed with new gaskets.
The fuel rail was put back in place.
A new fuel filter was installed.
New air filters installed.
Everything taken off was cleaned and replaced.
We were ready to start.
A short nod to the Jaguar Gods and we turned the key.
One crank. Two cranks. Rest. Three cranks. Rest. Hmmm.
Fourth crank and the Jaguar comes to life. High Fives!
It idled very nicely at about 1100 RPM for about 2 minutes.
Then the idle speed changed to a short surge to about 1700 and back to 1100 every 2-4 seconds.
What now?
The surging went on for about two minutes.
Then we tested the accelerator.
Perfect acceleration, but back to the surging at idle.
We let the engine idle and heat up to "normal" temperature.
Did several accelerator tests. They worked great.
The heat gauge moved up to "Normal Range" in about 10 minutes.

Then, as mysteriously as the surging started it stopped and the idle was back to 1000 RPM.

With the engine running we checked things:
1. We looked for leaks in the fuel line and around the injectors. There were none.
2. Oil pressure started at 60 when the engine was cold and moved down to 50 when the engine was up to temp. Good.
3. We noticed at Normal Temperature the Radiator thermo fan is not running. Moves a little.
4. With a white cloth behind the car to protect the garage and tools, the exhaust is very clean, no soot.

We turned the engine off.
It stopped intermediately.
Restart worked great. No surging after restart.

After tuning the engine off we noticed a serious antifreeze leak.
Seems to be coming from below the reservoir tank.
Investigation to be continued.

Questions/observations
1. We assume the slow start up was because there was no fuel in the filter and lines.
2. Good injectors do provide good clicking.
3. 12 Cylinders, all firing makes for a smooth running machine.
4. Is there an explanation or cause of the surging we experienced?
5. When is the radiator fan supposed to come on? When the engine goes above normal?
6. We will update findings on the antifreeze leak.

We will address the sticking brakes next.
Who knows we may eventually get to go for a ride.

Many thanks for the help and encouragement.

Best Regards,
Denny O

 

The surging is caused by a faulty Auxiliary Air Valve (AAV). This is a device attached to the b bank rear water manifold and joined to the intake manifold by a rubber 90 degree pipe. It also has a large bolt on it and this controls the idle speed. When the car is cold, the AAV opens so as to provide a fast idle for a cold engine. As the engine heats up the valve should close. If it s a bit slow in closing, or a bit faulty, the engine warms up and the idle rises, BUT the ECU knows the throttle is closed as the throttle position sensor is indeed showing a closed throttle. So the ECU thinks the car is coasting on a trailing throttle and, as a fuel saving measure, cuts the injectors. Then, as the revs drop below about 1300, it opens up the injectors again and the revs rise, and so on.
The AAV needs renewing or fixing, and Grant has a fix. here is a photo of the item:

 

I agree, BUT, the PreHE has NO 90deg elbow on top of the AAV, thank God or anyone else involved.

Yours has 2 X 90deg elbows below the throttle bodies, and pipes to the rear, and then an alloy casing sits atop the standard AAV, with more hoses. The balance pipe does NOT connect directly o the Inlet Manifold as it does on the HE.

My AAV fix.