Whoah !!!!!!s Carb fuel lines are designed for 3 - 7 or so PSI!!!!


FI is around 40 or so. Huge difference. Big danger.


A well known no/no!!!


Fix those or risk a "fire ball"!!!!


Carl

 

its r6 so its rated at 50psi which was his logic I imagine. it is considered low pressure.

the guy was a jaguar mechanic at a reputable shop... I still do not trust the hose. it has printed on it, "not for fuel injection". It was recently put on so I am not rushing to do it. It will get done in the coming weeks. I already pusrchase r9 hose which is rated at 100psi and has way better heat resistance. Something like 800 F. I imagine r9 hose on these cars will last a while. 60k or so. Maybe longer.

 

Firstly my apologies for replying sooner, I live in the country and internet here is by my mobile phone and not much of it.

When fault finding never assume anything, I have been repairing electronics for 35 years and when I have assumed I have had troubles finding the problem. Fault finding needs to take methodical approach. You start at one end and systematically work your way to the finish.

I would still start with an Italian tune up. You need to burn off any buildup of crud on the VALVES. I have a spare V12 (about 100k miles) engine and when I pulled it down almost every cylinder had 1 leaking valve, a couple of them were pretty bad. I know with my car it runs much better after a good long trip.

If the tune up does not work then I would start by pulling the injector plugs and finding which cylinders are not firing. (This will not harm the engine, pulling the injector plugs stops the injectors from squirting fuel so that cylinder will not fire. It will not harm the electronics or engine). Go through the process and double check plugs, wires, cap and rotor. If these are all good then it could be low compression from a leaking valve or rings.

Without an endoscope it’s impossible to check piston tops properly, but I don’t think crusty piston tops will give you the symptoms you have, LOW compression on one or more cylinders will.

I would assume anyone on this site would not even drive their car hard without fully warming it up.

OOPS I made an assumption you are correct never drive hard without warming the car up first.

 

Hi Warren, thanks for all your help with this, I certainly do appreciate it! I'm going to get at this as soon as I can, might take a while though as I'm back to work after some vacation time, so free time will be at a premium, also the free time mostly comes late at night, hard to do a lot of stuff without disturbing my family and neighbors. And yes, I do avoid driving hard before the engine is up to temp, always thought that was a good rule of thumb for any car.

Thanks, Eric

 

Guys, here's an update on the rough running problem. I finally found the time to try Warrens suggestion of pulling the injector plugs to find the faulty cylinder. I was pretty confident the problem was on the "A" side / right side, so I started by pulling all the injector plugs on the "B" side. Had to prop the throttle open a bit to get it to run, is that normal? Maybe so if there's a cylinder not firing on the other side. I went through the plugs on the "A" side one by one, all seemed ok except #2, which seemed to start working as I tried to remove the plug, then back out and on as I worked on it. Looks like my problem is either a bad connection between the plug and injector, or a fault in the wiring harness leading to #2. Not sure how to diagnose which problem it is? For now at least it's back to running smoothly, and I know where to start if the problem reoccurs.

From what I've read here on the group it would be no surprise if the harness was deteriorated, and replacing it sounds like either very expensive to buy, or lots of work to make, guess I should start doing my homework in either case.

One other question, I think the injectors are mounted in some sort of o-ring type setup, but they seemed to be able to move quite a bit while I was messing around with them. No fuel leaking out or anything, but is that normal? Or should they seem to be more solidly attached?

Anyhow, it's back to running smoothly, for now at least. I'm still planning to send out the injectors this winter, and go through the other fuel stuff, but for the next few weeks till the weather turns I'm going to enjoy driving it!

Thanks for all your help, Eric

 

The injectors are grouped, but basically the ECU has only 2 injector drivers so if you had one injector shorted to ground all injectors on that group (6 in total) would be open continuously, the car would run but be well down on power as 6 cylinders would be flooded.

So based on this I would suspect the connector or broken wire in the harness.

To put your mind at ease you could disconnect all injector connectors and ECU plug, then both wires on the injector harness should be open circuit to ground. NOTE for this procedure to work ALL connectors need to disconnected.

 

Good find, congratulations. You can be pretty sure it is the harness, and that other bits of it are near-fail too. I think you would be very well advised to stick a new one on ASAP, home-made or bought, Jaguar still have them. When the injector loom gets iffy an injector sticking open, rather than not opening at all, is just as likely to happen and is far more serious a fault. All of 30 minutes work to change it.
Greg

 

Just to butt in a bit, when I had a misfire on one cylinder the mechanic used a stethoscope to identify which one wasn't firing so it wasn't necessary to remove the plugs to check them; it took about 20 seconds to check the whole lot and identified the misfiring one straight away.
It turned out that someone had bent one of the connector pins up when replacing the plug so it wasn't making contact at all; problem sorted in less than a minute.
One thing it should be good at is that you can listen to each injector in turn and waggle all the associated wiring to see if there is a break somewhere stopping it firing.


Silverline 320mm Mechanics Stethoscope 154006 | eBay