No. You can also test each system individually one at a time and ensure that each is functioning properly before disturbing anything else.

But it's your car.

In my opinion there is no reason to indicate an ECU problem in anything you've posted.

Install a fuel pressure gauge. Confirm your rail pressure.
Pull the rail. Test the injectors for action and pattern. Replace.
Check each plug lead for proper spark.
Reset the timing per spec for your engine.
Drain fuel. Check all fuel filters. Add fresh fuel.
Test and set the TPS. Again if you already have.
Test the CTS.
Test the ATS.

If you still have the same issue without any problems with the systems above then check compression on all cylinders.

Or jiggle all the wires and wave a dead chicken over it.

 

Tony
You did replace the leads in an anti-clockwise order? Please remind me of the model and year of your car.
Greg

 

Greg, all leads are in right place, anti-clockwish, starting with A1 at mark on dis cap. car is 1989 xjs conv with lucas ign, 5.3. i now there is pressure on rail, so ill remove pipe going to FPR and fix a gage with tyre pressure from compressor on it and see what pressure goes to rail before it opens,

 

have just got phone call from classic jags, i ordered a FPR 2 weeks ago can pickit up 2mw, will see what happens with it on.

 

It must be the B bank one that you change, remember, (or both). They are NOT the same pressure.
If after that the car does not start, and the fuel spray is still good, then it has to be the spark.
Also have you tried squirting some easy start into the throttle butterflies, as mentioned above somewhere?
Greg

 

yes tried easy start never started.

 

You should have posted that earlier. If easy start does nothing, then you have a spark problem. Whatever test you did on the plugs for spark is misleading you.
Greg

 

If it doesn't fire on ether then you've no spark or you're Firing them on the exhaust stroke.

Have you checked cylinder 1A is at TDC when the dizzy points at its post? Have you confirmed spark on all plugs?

 

1A needs to be TDC on compression stroke not the exhaust stoke.

You need to go back to the start and work through this methodically or you will never find the problem/s. I suspect more than one fault is causing your issues.

Pull the injector loom off the engine and check it for fractured wires and damaged insulation. Broken insulation is a very common problem. If good then re-fit it. I know it doesn't start with easy start but you need to confirm the loom.

Next check the coils with a DMM on ohms primary should be around 1.5-2.0ohms, I couldn't find the Jaguar spec.

To test HV take the lead from the coil to the dissy out of the dissy and hold it 1/4 inch from an earthed part then turn the ignition to position 3 to start.

 

new FPR fitted to day still no start, good spark from plugs inj working, and compression fine, petrol in tank tested all fine, no water or rust, only thing left is ECU Tony

 

Tony

Stating the Blinkin obvious here!

But did you Check this Cut Out Switch, which has been know to Trip and Stop the Car!

Its on the Passenger Side on a UK Car just beside the door jamb.

To check it or reset it, push the blunt end of a Pencil down the hole and if it has somehow tripped

itself then push the button down until it locks.



This is the 'Cut Out' that shuts the Car down in the event of an accident.
Push the blunt end of a pencil down the hole of this cover in order to Push down the Button Inside and re-lock it.

 

orangeblossom first thing i checked, i give up taking ECU to be tested monday will take a couple of days before i know.

 

Are you dead sure the car is timed to the compression stroke? If your spark was right, then the car would run on ether. The reason why not is still undiagnosed and the ECU seems unlikely unless your spark is not actually as stong as you think it is.


As to fuel, recheck that the plugs are wet after you have tried to start the car. If all is working properly they should be very wet after 15 seconds of churning. If not, then you may have some fault that means the injectors are not getting fired during the starter motor sequence, or the ECU is not getting a signal from the amp - ie the dreaded shielded wire fault. which would point towards a starter relay problem or an amplifier problem
Greg

 

ECU is injector boss. If it was the issue you'd have no injection.

If all the above is accurate and your timing is reasonable then your region must be experiencing a spate of oxygen-free air.

Edit: correction

 

may be ECU is sending signal to inj and plugs at wrong time, i know i'm getting very good spark and i'm getting fuel from inj plugs getting wet, i don't know what is happening, every body on site was saying FPR faulty, that's new has new fuel pump, fuel filter, cooling sensor, new coil, all relays working, i'm out of ideas.

 

The ECU is triggered by the distributor. The distributor determines the timing of the spark by creating a voltage spike with its pickup. This signal goes to the amp and then to the coil. This discharges the coil into the dizzy cap. The ECU uses this same signal to trigger the injection pulses. It can't be wrong on its own.

Have you checked the timing?

Have you ensured that the engine is on compression stroke when firing?

If you need suggestion on how to do these two test just ask.

 

JigJag is correct if the ECU is firing the injectors and ignition (even at the WRONG time) then the ECU is good, but the inputs to the ECU are timed wrong.

You will not the problem throwing parts at it. You need to work methodically.

Can you post a description of the issue and a list of everything you have done as this thread is difficult to follow.

 

Had same problem. Parked car and a couple of weeks later it was a no go. Took me 6 weeks to figure out that even though I thought I had good spark, the coil just wasn't giving enough.

 

O/K car has had new battery, new fuel filter, new fuel pump, new coil, new FPR, new cooling sensor, new plugs, cranks over trys to start, fires once and keeps on cranking, good spark from coil and plugs, over 200psi on compression, had a1 & b1 inj out fuel going in, spray east start in still no start. had finger on a1 bank plug hole on compression stroke rotor arm points to no 1 in distributor, Tony

 

This is a good summary. Doesn't answer all the questions, but it's enough to make me think you should be running; on ether at least.

So, what are those plugs gapped to? It will not fire with a gap over .025". Given the info above and no fire on starting fluid I have to assume you're gap is too large and your spark is finding an easier route to earth.