I did a search on this and read till my ability to absorb ran out. Can't get OBD2 codes right away.


Intermittent starting problems. Most of the time it fires right up but then sometimes it won't even sound like it is trying even though it cranks strong.


Today was really disappointing because it had been starting regularly. So I set out to have the oil changed and the codes read. The oil change guy could not get it started and when I tried it seems that it was not even close so I left it and will go back tomorrow. It seems that the it gives its best shot to start when the ignition is first turned and if its not given gas at the right time it then will not start and not even try.


I read JagRepair.com - Jaguar Repair Information Resource and some other tings but since this is intermittent perhaps someone can offer some good advice.


Thanks in advance.

 

Your descriptions of the non starting episodes could be fuel pump. Seems to happen a lot (to me, too). A failing pump might be intermittent. May also be electrics driving pump, connectors and relay. Schematic is available in stickies at top of forum.

What is behavior when it does start? Just fires up? (I think you said that above, but I'm on smart phone...)

Steve

 

Yes, engine cranks and fires up with a little help from the gas peddle. When it doesn't start it just cranks and no attempt to fire. Seems that when it tries to start and doesn't quite make it takes a break ( very long ) before it will attempt to fire up again. Nickasel engine so I thought maybe compression loss, cylinder wash - but reading on that seems not to be the problem. I was going to add some Restore with the oil change though.

 

A few suspects:
1. bore wash
2. bad fuel pump
3. blocked fuel filter
4. air leak(s)

Cheap OBD tool is about $10....

 

Good tips, thanks. I was able to get the car started today and drove it home. I'll buy something to get the OBD 2 codes or perhaps even an app for my iphone.


If the fuel pump was the problem, why would a long delay increase the chance that the car would start. It seems that any intermittency of the fuel pump would be a random event and not remedied by a long rest period.

 

Next time it happens (or sooner, the more info the better) see if you can get a fuel pressure gauge on the car. Or, during one of those no-starts, check for pressure by depressing the schrader valve before and after cranking to see if you have good pressure.

 

Often the pump problems worsen after a long delay, but there really is no 'rule', and there can be different failure modes.

Definitely get the OBDII reader, but be aware that a fuel pump failure is not directly detected over OBDII.

 

I'm confused.

You speak of codes,does that mean you have a check engine light?

 

The lights that come on relate to the ABS and brake system but not a generic check engine light. Someone told me to read the codes and post them here so I orders a wireless code reader. I was looking under the dash to find how to plug it in when it arrives and did not see an open plug. Under the steering wheel there was what looked like a plug but it seems like it was connected to some sort of terminal. I will research here to see how to plug it in.

 

Thanks, now I just have to figure out how to find the Schrader valve and to read the fuel pressure. I'm still learning the basics. I haven't done much in the way of auto mechanics since my late teen years. I'm looking forwards to becoming minimally competent to do some things to keep the Jag running.

 

Search out fuel pressure in this forum. You'll find all you should need, including Paul's JTIS diagram of the valve's location. Getting or downloading a copy of JTIS will be a big help. Look through the stickies at the top of this forum page. And don't worry we'll get you back to skinned knuckles in no time.

 

Just a thought, how old is the battery? If it attempts to start easier when left it would tend to give the battery time to recover its charge, more cranking depleats the charge. I would check the condition and power of the battery, its just a thought.

Arty

 

Good thought but the battery is brand new. I just changed oil and added Restore in case there are compression issues. spark plugs? Got to keep plugging till she starts without hesitation.

 

How about the air filter? As far as the fuel pump I understand that the Schrader Valve is under the driver side engine cover. Some members seem to have a hard time finding it. Does it look like a bicycle valve? Is there an economical way get it tested? Is there a cheap tester I can purchase. I found a few on Amazon but would like some input on this. Thanks

 

It seems to start a little more decisively since I changed the oil and added Restore. The engine seems to miss when idling makes a brum brum sound from time to time. My code reader should arrive Monday so I can read the OBD codes.


I'm trying to be patient and remember that the car set up for a few years. Thanks in advance for all replies to this novice.

 

JTIS Shows the Fuel Pressure Port at the back end of the Right Side Fuel Rail (on XK8s):



Harbor Freight has a Low Priced Fuel Pressure Tester:

Fuel Pressure Tester & Fuel Injection Pump Tester

 

Well, the starting problem persists. By the way, Paul, your car is beautiful. My xj8 is BGR coupe also and I really want to restore it.


The Schrader valve( fuel pressure port), I read is in front of the driver side valve cover. Do I have to remove a cover to get to it to find the valve and pressure test it?


It seems that the car was starting before it was out of service for several years. The initial problem was overheating severe enough to rupture the holding tank. Is there anything about overheating or sitting up that would cause a starting problem.

 

The valve is on the passenger side (US) near the rear of the engine. Pull off the plastic engine cover and it's right there on top of the fuel rail. There is another one back near the firewall that is the AC charge port. I believe you should get about 40psi without looking it up.

 

When I turn the key I get good crank and immediate firing and if I push the accelerator as soon as it fires it usually starts right up. I understand that the accelerator to the floor cuts the gas to the injectors. If I don't get it started then it takes a long rest period before I get the strong initial firing. It seems to me that the problem may be in the throttle body or whatever regulates the gas to the cylinders. That said, I'm thinking of getting the equipment to test the fuel pump and the cylinder compression before I tinker with the throttle body. I surely have some sort of problem with the throttle body and I discussed that in another thread.


https://www.jaguarforums.com/forum/x...riving-115776/


Thoughts please.

 

Read the codes and get a fuel pressure reading. Jaguar will tell you if the TB service action was performed. Anything less is guess work and cost money!