Trying to get a 97 XK8 to run. She will fire up but run rough for only a few seconds and then stall out and will not start again for hours. It seems like once the pressure rebuilds in the fuel system she will start but again not stay running.

The fuel filter is clear, tested pressure at the fuel rail to be 40-41 pounds while cranking and 35 pounds with key on.

No check engine light or codes so far.

Any suggestions what to look for next?

Are there any other sensors that would prevent it from running or am I going down the wrong path thinking its fuel related since it does start but won't stay running?

 

Your car has 2 fuses for the fuel pump. One fuse that primes the pump then once the car starts the other fuse takes over and provides a constant feed to the pump. This link should help.

Link JagRepair.com - Jaguar Repair Information Resource

 

I'll look into it, thanks. I'll let you know what i find.

 

There is also a relay in the dash with a switch on it. You might want to check that. I had to do the same on the car I inherited from my brother but it had no fuel pressure at all. The switch had popped out and even though I pressed it in the car would still start and run rough. I took the relay apart and cleaned it and put it back together with dielectric grease. It ran perfect after that. Just a thought.

 

Voltages look good, any chance the fuel pump is failing between the prime stage and the constant pressure stage?

 

Joelsjag - are you referring to the inertia switch? I'll check that. I thought if the switch was tripped the car wouldn't even start. Are you referring to the triangle shaped access panel on the side of the dash?

 

My first thought was failing fuel pump, you may have to consider that.

 

If it were the inertia switch the doors would no lock the and several of your electrical devices would not work.

Did you say you checked both fuses? You pulled them and tested them? Most of the time when the pump is done it is done and will not put out 10psi.

Gus
www.jagrepair.com

 

Yes I tested both fuses, I also had a pressure gauge on the fuel rail showing 35 PSI with Key on and 40 PSI for the few seconds it ran.

Are there any other sensors that could be shutting her down after startup?

 

Don't just guess ....... put a scantool on it.

Graham

 

When you checked the fuses did you pull them or just tested them in the car? I found pulling them and testing them is the real check. If they are ok then swap out the relay with another same relay in the car and see what takes place first. Question: when you turn the key on and leave it on does the pump continue to hold pressure?

 

Can you share a bit of the history of the car? Has it been sitting a lot? What is the condition of the battery? As you crank over time, is it being recharged in between? The battery needs to supply cranking power while maintaining enough voltage to operate the electronics. Folks have repeatedly suggested the battery needs to show well over 12V at rest to be considered "good"...

More generally, the first year car has historically seen its share of major ECU and throttle body problems, typically requiring a rebuild. Besides that, check all hoses and connections around the throttle body ('97 had a vacuum-based cruise control, I believe) as well as the integrity of the intake elbow. The air flow meter might be something else to check.

You might also want to read about the early secondary chain tensioners and decide if you even want to get this car started at this point.

Last, you might want to check the procedure for starting a flooded engine, typically labelled "bore wash". As your car starts, this is probably not applicable, but might explain the fact that your car only starts every few hours.

Best of luck, keep us posted.

 

Thanks to all for these suggestions, I will go through all of these again and double check everything and report back.

Nothing came up on the initial scan, I just bought this car as a no start from an older gentleman with way to many cars and money for 1,000. It's in great shape minus the no start, new paint, no drive train leaks, clean interior and wheels and tires. It's a coupe and my wife really liked it so it's now in my garage.

 

When cranking does it spin like it has compression or does it spin faster than it should? Might be a tensioner or bore wash problem.



Dave

 

DaveinVA

It definitely has compression, So i dont think there is any issue with timing as it does start and run for 10-15 seconds before it sounds like its starving for fuel and shuts down.

 

I would still look at the fuel issue. The fact that the car starts and then cuts off is telling me you have fuel to start then it cuts off. Check the fuses and the relay first then put a fuel pressure gauge on it and see if the fuel pressure drops off after the engine starts to confirm the pressure. If I recall the ECM takes charge of the fuel pump power and that is another variable.

 

Yes my brother let the car sit for months and when he tried to start it; it would just turn over. He had 0 fuel pressure when he pushed down on the Schrader valve nothing came out. Sounds to me like it has some kind of electrical gremlin.

 

Computer? Seems like he has checked all the fuel related stuff, relays, etc. You did run a scan for codes?

 

Possibly the MAF sensor is totally shot or disconnected.
Starts, but dies as soon as MAF data required. Have seen this on other vehicles with no codes for some strange reason.
Best of luck.

 

My BMW was hard to start. Took her to the best shops in Los Angeles. No one knew what the problem was. Then she stopped starting completely. Telephoned a pal with a tow truck, he was busy and could not come. He told me to open the fuse box under the hood, remove the fuses (fuel pumps) and sandpaper them a bit. I knew he was simple and did not know what he was talking about as I am an electrical/mechanical engineer, but I did so. The car then started right up and was perfect for years to come. The metal tips of the fuses sometimes tarnish, resistance goes up, viola. It is possible that the Bavarian worker that had originally installed those fuses had just finished his lunch and having eaten his sausages with his fingers.
I met a guy in a gas station years later, having the same problem, he had just paid thousands of dollars for the repair, still had the same problem, I sanded his fuses, his car started right up and was good as new.

Just a thought.....