1989 xjs v12 no spark
 

Hi All,

I am new here and I have 1989 Jaguar XJS 5.3 V12 with Marelli Ignition system and it doesn't starts.
So yesterday I changed:
1. Fuel Pump
2. Ignition Lead Set
3. Spark Plugs
4. Distributor Cap with gasket, filter and new Rotor]
5. 2x Coils
6. 2x Ignition Moduls (Amplifiers)
7. Crankshaft Position Sensor
8. Flywheel Sensor
9. Water Temp Sensor

And after all... the car doesn't starts. There is fuel in the rail, but no spark on both sides. Even I take one plug out and touch it to the engine and nothing, no spark.
Please help. I don't know what to do and where is the problem.

Have you checked for 12 volts at the coil when the ignition is switched on?

Yes I try it, but there is no 12v on the coil

Firstky, welcome to teh Forums.

When time permits, please do an Intro in the New Members Area.

No 12v at the coil, mmmm

Does the car have an imobiliser, as in factory or aftermarket. Either of these usually cut voltage to the coil when activated. They also reek havoc now they are getting old.

OR

The ignition switch electrical section needs dismantling and cleaning, It is a seperate item to the Key mechanical section. Locate the rear of the switch, and probe the solid Brown wire with the switch in POS #0 (Off to some), it should have battery voltage. If so, then you have power TO the switch, then test the White/Pink with the switch in POS #1 (accessories to some). You are looking for 12v here also. Then POS #2 (Ignition to some) White wire should have 12v. Then POS #3 (Start to some) White/Yellow, and 12v again.

I reckon the White/Yellow is OK, as you say it cranks but not actually start and run, I think??

If there is NO volts in that Solid Brown wire, then there are supply issues, but one item at a time.

At the rear end of the engine at the center is cylindrical electrical socket, which has two wires, one thick is plus for ignition coils, thin is for ignition pulses. Often this connector is corroded. The connector is black, the wires are white (if I remember correctly)

No 12v supply to the coil is the first problem to solve. Try hot-wiring the coil from a 12v source and see if it will start. If so, you know it is the ignition switch circuit.

Hi Dimitar

The Marelli Car has Two Coils:

Coil 'A' the Red One is the Lower Coil

Coil 'B' the Yellow One is the Upper Coil

Maybe you have got these connected the wrong way round?

If so you won't get a Spark and She won't Start (ask me how I know, or rather don't

Also Check the Fuel Pump Cut out (just to cover all bases)

There would still be a spark if they were wired wrongly.

Most important right now is to get power to the coils...

здравейте казвам се йордан колев наскоро си купих xjs v12 и имам проблем с паленето искам да се свържа с вас ето и моя тел.0888 207313 благодаря

Welcome to the forum Yordan,

ENGLISH only on the forums, please.

I think you are writing in BULGARIAN that you also recently bought a 1989 XJS 5.3 v12 and have a problem with the Marelli ignition and it does not start ......?

Graham

Thank You All for the answers. I will continue to search for the problem. Now I will test all the leads from Ignition control module to the coils. Maybe it is a broken cable.
I will give 12v to the coil to test, does the car starts.

I will write after that.

Thanks, ones again.

I will hlep Yordan, he has the same problem.

You should have 12V on the White wire at the coil, If you have no 12V at the white wire you need to fix this first. It comes from the ignition. This voltage also goes to pin 13 of the Marelli ECU and pin4 of the ignition modules. If you have NO 12v at ALL of these places then check the ignition switch