So about 8 months ago my car had this weird problem every now and then where it would get power to windows etc but no insurment cluster power or starter power. A quick take off and back on of the neg power terminal fixed it.

I found there was quite a bit of build up of corrosion on it and brushed it up and replaced the terminal and haven't had a problem since...untill today. Went to work but when I tried to go home the same thing happened.

So I tried my old trick and my power seats quit working(along with the custer/starter). Then the seats started working again. So I wire brushed it real well and jumped the car with a friend. Still culd not get any power to the cluser/starter.

The odometer shows some cut up version of the mileage or some other code but that is all. Checked all of the fuses that I thought might cause this problem as well.

My next guess is the ECU(as my car has been acting up in other areas as well). This is a really bad time for me to loose my car (and in the wrong city) Hope someone has some insight

 

g,

Better days are comin'.

Do you have a good battery?

The other end of your -tive battery cable is a ground connection. What does it look like? Remember, grounds make up 1/2 of your car's entire wiring.

Also check the major connections of your battery +tive to alternator and starter motor.

What year car and model are we talking about here?

Cheers

 

I will do that, I didn't have any tools with me to mess with any of it but the ground to the car looked like it could use a cleaning. However the battery itself seems fine. I was going to take it out but since it did not put any load on the vehicle jumping it and everything works perfect except for the stuff that is supposed to happen when the key is turned all the way I left it.

The car also has a problem that sometimes when you start it and go it has huge loss of power, can't go over some number of rpms etc. This morning was especially bad and I could hardly keep it at highway speeds. My solution is to pull over and turn off the car for 15 seconds and go again. That almost always fixes the problem and it worked this morning.

Right now it is sitting in an Air Force base parking lot so it is safe, but also harder to get to and far away from 'home base'.

 

g,

Ok, I read you own a XJ40/ Sov/ 1990.

Make damn sure that battery is good. A battery of high internal resistance won't allow much of a charge to go through it.

That my friend sure reads to me as a failing fuel pump. When they get hot, they quit working properly and the engine misses and sounds like it wants to fall out of the chassis.

If you haven't bought a Haynes, yet, please do so. It is one of the few I've read and used that is not a joke.

Here's a wiring diagram for car - the diagram on the left is applicable, I believe, in your case.

Start&charge_system.pdf

Do you know where your car's starter relay is located? I don't mean the starter solenoid.

Cheers

 

GUNNER! Man you have worked so hard on that car! As the above posting says, fuel pump is in need of exchange. I'm sure you read enough on here about batteries on this car. I think you need a new one. When mine was going I had so many odd symptoms I couldn't tell one problem from another. New battery fixed all of it, including some rare VCM code numbers that haven't returned. These batteries need major juice, mine read 12 across the terminals but needed more than that to get it to fire. It would turn over though. Of course she wouldn't recharge either from the ALT. Let us know.

 

Ok, I will take the battery and have it tested/replaced. Pray like hell that works some magic heh.

Like a clown I let my AAA expire so I need to wait 7 days before I can tow it home. Luckily it is in a safe spot, just not an easy spot.

I agree that it sounds like the fuel pump and it could be since I replaced the old one with a cheap AirTex last year. The funny thing about that is it dosen't happen all the time. Some days I can drive 100 miles in 80 degree weather non stop and have no issues. Others I can't accelerate out of my driveway in 40 F weather but a quick off and on generally fixes it.

I will replace the pump to a higher quality one, if only to kill the wine that this pump has. I do have an haynes manual, don't know where I would be without it.

Looking back I have worked like hell on this car but it has only completely borken on me twice: once it wound up flooded worse than the Mississippi because of a faulty fuel pressure regulator, and now this.

 

gunner:
All good suggestions. Your '90 MY must have the external fuel pump, otherwise you wouldn't be so quick to replace it twice in one year! I'm not sure though, if you haven't already, I'd go through the battery of tests related to fuel pressure. There's lots of possible faults. When's the last time you did a good old fashioned tune up?
I think Trick is right, btw... check those grounds and the battery. You may be all right!
Scott

 

Yup it is the external The last owner had replaced the orig one with a Bosch but that started to have the same stall problems the stock one had in high head. It worked better once I wraped the fuel rail with reflective tape but I replaced the pump anyways.

Haven't had it tuned up in long time, been meaning to get it done this summer. Just wanted to get the check engine light off before I did it (EGR circuit prob). If the battery dosen't fix the problem I am going to take it to jag and tell them to find out whats wrong with it and have it tuned up.

It has new sparkplugs, fuel pressure regulator, and cleaned throttle body. Which is about all I have done with the ignition system etc but it would def benefit from a tune up I am sure. I keep up on the maintenence though very well, new antifreeze this winter, reg oil changes, just replaced dif and trans fluid, new brakes, new O2 sensor. I fix anything I can on it just because i kind of like doing it.

I am holding my breath it is just a funky battry issue ike before. If not off to the dealer....

 

Gunner, quick response because I'm off to church. But, isn't the whole reason Jaguar went to the in-tank fuel pump design with the '91s precisely because of the prevalence of the behavior you are describing? And if so, not only will there be quite a number of people who have had this problem and fixed it, but also some good suggestions out there regarding a remedy. I'd so some more digging in the archives here and in other places on line. Perhaps you'll find something!
Cheers!
Scott

 

Yes, Jaguars remedy to the fuel pump problem is to use 2 pumps. I think they specify to put them in parallel.

However my current problem is clearly 100% electrical since there are no dash lighs(the odo only shows partial) and it wont crank.

I took the battery out today and took it in for testing. The tester showed it at 54% charge but still said good. Once it charged to 100% the charger showed that it was no doubt a good battery. I cleaned the ground point and reinstalled. Did not change any thing.

So it is off to the pros for her next week...

I keep thinking about what Jag says: prolonged moisture over the windshield air intakes can cause water to seep into the ECU and cause a failure. I had just gotten a car wash the day before but I am sure that is just me chasing ghosts. However a sudden failure like this without reason sure does lend a good hand to computer failure of some sort.

Like I said off to the pros to diagnose. Will inform the thread what the findings are.

 

Looking forward to hearing good news from you

 

I'd exhaust what I could do before trucking her off to a dealer or Jaguar repair place.

"Starter won't crank", read your Haynes.

It's gotta be at least one of the following:

1. faulty Ignition Switch
2. faulty Ignition On Relay
3. faulty Linear Gear Position Switch (determines if in "P" or "N" and sends signal to ECU)
4. Engine Management (ECU) fails to close N.O. contacts in Starter circuit after receiving "P" or "N" signal from LGPS.
5. faulty starter relay
6. faulty starter solenoid
7. faulty starter or
8. faulty wiring (and/or grounds) interconnecting these devices.

Most of these can be "tested" with a simple ground wire (or test light) and a little reasoning on your own part.

I'm not a pro - I've just worked on my own cars since I was 17.

I, too, am looking forward to reading about your repair service's findings.

 

So I got it towed home as a good friend said he would look at it. He is a certified mechanic so figured id save the dough. He was going to come over today and I got out my Haynes to have the wiring diagrams ready for us to start working with and I flipped to the page that dealt with the inertia switch.

I read it and thought "hmm thats kinda what happened lets check it out easy check." Low and behold there it was sticking up in all it's red glory. Pushed her back in and I am back on the road. Dumb luck that I turned to that page, but glad I don't need to spend more time with it

 

What ? !

He was just a scammer with a spam signature, he's banned

 

Hi Regent, I think it may be a good idea to post more about what was going on, so that other members, who join this thread after, understand the situation with that idiot........Roger.

 

Can I just say, though... that I don't remember a time I had as deep a belly laugh as when I read that post followed by Roger's response. I copied it and immediately sent it to my wife. I don't know... I just found it really funny. I had no idea what it meant.
cheers,
Scott