83 xj6 no start, no injector pulse...help?

Just a thought, Lee...

Being a certified mechanic for 12 years, I would think that you've checked the wires from the ECU to each injector. I'm not sure what FI system is on the '83, but I'm assuming it's the Bosch system, since my '88 had that and my '77 280Z had the identical system, just a little smaller. Anyway, had the same problem with the Z car, and it ended up being the injector connectors. Needed to clean them a lot, as the connectors were old and would corrode easily.

Mark D. Washam
98 XJR

I presume you got hold of some good diagrams but, in case you didn't, I sent some stuff to you 0ff-list (so, if you see an e-mail with attachments, don't worry !)

If it comes down to replacing the ECU, they come up on "Ebay" fairly often....

Cheers
Doug Dwyer
JDRC/NWA

well ive tested and retested every single wire going to the ECU.
they all do what their supposed to. and the coil circuit to the ECU is working. what other signals does the ECU use for injector spark.

i even checked the ignition switch, cleaned every ground wire i found and every connection i could see. and still no injector pulse.

i put a little gas in the intake and she purrs for about 15 seconds,
so i know injector pulse is my only problem

wanna buy a jag cheap?

XJ6

ECU failures are rare on these cars but, of course, they do occur. Lot's of supposedly good used ones come up on EBAY quite often.

For a really good wiring diagram, call Jaguar Services and ask for the "S57 Electrical Guide". You be glad you did, a great resource, and only $30 or so. (the number is 708 331 9151 800 842 0912). These also come up on EBAY quite often for very low prices.....

Cheers
Doug Dwyer

well, ive tested evrything i can. but still no injector pulse.
what are the odds that i have a bad ecu?
do you know where i can get a usefull wiring diagram?
i hate to admit it, but ive been a certified auto tech. for
12 years. and this car has beat me. im lost.
i just cant find any reason for there to be no pulse.

arrggg

XJ6

Lee, regarding the coil wires.....you're really just looking for any which may have been accidentally broken or disturbed during your other work. These wires become very fragile with age.

The white wires are voltage supply from the ignition switch. The white/black wires go the the ECU and to the amp and distributor. One of the wires goes to the tach...white/blue, I think.

Anyhow, just look for anything broken ....

Also, at the end of the water rail is a bundle of bround wires....make sure these are OK. Nearly the entire F.I. system grounds at this point.

Good luck
Doug Dwyer

well im getting power to the resistor wires.
the relay checks out. and so does the resistor.
im not sure i reconnected the main relay correctly,
my wiring diagram is almost usless.
im almost to the point of just replacing the relays and other components just on general purpose.
you had metioned somthing about the coil wires. i checked these the best i could without the proper diagrams. could you elaborate some on this.
i am chomping at the bits to drive this thing.

thank you very much for your help

lee

XJ6

Couple easy checks:

On the firewall is the "main" relay. It has brown, black, brown/slate, and white wires. This relay provides voltage to the injector ballast. With the key "on" you should get voltage on the brown/slate wire. If not, you have a bad realy or a wiring problem. More details if needed. You can bypass it for testing by removing the socket and jumping the brown and brown/slate terminals.

From there the power goes to the injector ballast, right fenderwell, across from p/steering pump. Check connections. The ballast itself seldom fails.

Check the wiring at the coil... it gets very brittle with age. One of the white/black wires goes back to the ECU in the trunk to provide a "trigger" signal.

Post back !

Doug Dwyer