hi can anyone help with a problem i have with my xj6, it started running a little rough, now it wont run at all, it starts for a few seconds but then dies, it feels like it runs on the cold start. ive changed fuel filter all hoses in the boot , measured the fuel preasure ( which is ok ) new plugs, check the fuel relay ect
when i move the flap in the afm the pump starts and i can hear fuel running through the system.
i have sparks on all plugs.
????????? help

 

An easy first step.....

Is the ducting between the AFM and the throttle body secure and leak free?

Cheers
DD

 

Welcome to the forum ken1,

I've moved your question from General Tech Help to XJ6 Series I, II & III forum. This is the place to post questions about your model.

When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

Hi Doug
yes ive checked it. its sitting as it should, ive take the airfilter house off.

 

This is good but, still, your description of the problem sure sounds like a fuel delivery issue.

Just for the heck of it hot wire the fuel pump just to positively eliminate it. It'll only take a minute.

Remove the fuel pump relay. The socket will have one or two cavities with white/green wires. Run a jumper wire from the battery "+" post (or any constant 12v source) to both of the white/green wires. One or the other will make the pump run constantly.

Now start the engine and see if anything changes

Cheers
DD

 

hi Doug thanks.
done that, its the same, if i disconect the afm it runs on tickover but i cant gas it , it just die,s im getting fuel to the rail at 28 psi. i know i have a fault on the return valves to the tanks to, it returns the feul to the wrong tank.

 

it seems to be a simular problem that docppo had last march. but he didnt post the fix lol
https://www.jaguarforums.com/forum/x...nnected-91805/

 

It's been many years since I ran Series I and Series II and Series III was one of the few models I missed owning but .....

....... does Series III have the same AED (Automatic Enrichment Device) as the earlier models? If it does, I had exactly the symptoms you describe with a Series II 4.2 which turned out to be a failed AED.

If Series III doesn't have this, just ignore me!

Graham

 

This is really weird.

I'll do some mulling.

Cheers
DD

 

A Ser III with the 3.4 engine, which runs on carburettors, has an AED, yes.

The 4.2 fuel injected cars have a cold start injector that sprays a extra slug of raw fuel into the inlet manifold if the engine is cold. It operates only for a few seconds and only if the starter is engaged. To prevent flooding a thermotime switch defeats the cold start injector if the starter is operated for more than a few seconds or if the engine is warm.



Cheers
DD

 

Unplug the cold start injector. Any change?

Do you have voltage to the 6 regular injectors? Are they ticking?

Cheers
DD

 

it runs on tick over if i disconnect the air flow meter.

 

Oh, yeah, I forgot that part.

So obviously the injectors are functioning, at least with the AFM disconnected

Still mulling

Cheers
DD

 

ive just striped the injects out, to discover a brown sludge clogging the fuel intake pipes of each injector, ive got a gut feeling this is the problem. When i changed the fuel filter it did,nt show any rust partickles as you normally get with a rusty fuel system, so i think its been changed before i think.well its changed now. So ive left the injectors in to get sonikly cleaned.
The car has been sat in a barn in Italy for 22 yrs, im guessing the tanks may need cleaning out properly and coating on the inside.

 

runs like a dream. thanks for everyones advice.
time to fit a motor heater in the motor cooling system.