Drove my car for a while the other day, then parked. Couple hours later, I went to start her and for the first time in over 60,000 miles, she balked. I tried three or four times without success. If I remember correctly, it didn’t sound like the engine was firing, just cranking. Got out for a couple of minutes, got back in and she slowly started up and barely kept running. I drove her, stumbling and sputtering, about 40 feet up my driveway and went off to dinner. Came back a few hours later and tried starting her. Instantly, the car started and settled down to a normal idle. Drove her around the neighborhood and everything was normal. Next morning, I checked for codes and was surprised to find there were none. That was almost a week ago. I’ve driven probably 40 – 50 miles since and there’s been no reoccurrence. She runs as well as she always has. I’m figuring if this happened once, it’s likely to happen again, maybe 100 miles from home. Any thoughts as to what could cause a momentary no-start would be appreciated. Thanks!

 

Just guessing at this point. Fuel pump?

 

You need three things for starting:

1. rotation
2. fuel
3. spark

You had (1) and, as there were no codes, I'd also be thinking of fuel pump as first cause.

Graham

 

Thanks, guys. Yeah, the fuel pump is my best guess. Not sure if there's any way to test a pump's condition, or if I just have to wait until it fails. That's one job I don't want to do preventively.

 

It wouldn't hurt to change the fuel filter, unless it's been done recently.

 

Since you have a 2005 you will have the single fuel pump setup and in that assembly is a cheesy plastic check valve. The intent is to prevent the fuel draining back to the tank as the heat from the engine warms the fuel and causes it to expand and build pressure.

If the check valve fails, the fuel expands, pushes some back to the tank and then when cool again, leaves a slug of air in the fuel rails. This causes an extended period of cranking then some amount of stumbling before settling into a normal idle.

My 2003 does this. I had the pump replaced once at great expense because of this problem, but even with the new pump it came back a few years later and I have just put up with it since. Cycling the key a time or two can "pump up" the fuel system and helps.

If the pump is running, there is never a problem, it is only in the case of a warm shutdown where it happens.

 

I agree with the initial approach of changing your fuel filter if you have never done so. I changed my wife's 2006 XK8's original fuel filter (dated April 2005) right at a year ago at just over 90,000 miles and was really surprised at how greyish-colored the fuel running out of it was. No question that her fuel pump was having to work harder than normal to push fuel through the old filter and up to the fuel rail. I sure won't wait another 90,000 miles to change the fuel filter again (assuming we keep her car that long)....

So change your fuel filter if you haven't already done so and let us know the condition and color of the fuel it contains....

 

Charlie, I am going assume you are right. ;-)
If it doesn't reoccur in a month or so, maybe I'll be able to stop holding my breath each time I start her.

 

Jon,
Checking the filter will be #1 on my list. Thanks!

 

hi im having a problem starting my xj8 1998, 4.0 ..starts fine ten times or so then i have to turn the key 3 times to get it to fire up, it cranks but doesnt fire, it hasnt let me down yet but i was wondering what your final solution was,? was it a failing fuel pump causing your problem? i have only had the car a short time ... i have started a thread to try to get some info on this and any help would be appreciated, many thanks

 

See if this information helps.

Link to No Start JagRepair.com - Jaguar Repair Information Resource

 

My no start has not reoccurred.