Hot Start Issues With My '99 Jaguar XK8

[nofear365]

Hi everyone! Just pulled my XK8 out of storage about a month ago and have been enjoying it ever since!

However, today I had an issue that seems to be repeating. This morning it fired up immediately. I drove 45 mins to work and it ran FLAWLESS. I pulled over to get coffee and when I returned the car wouldn't start. It cranks and cranks but it won't turn over. I tried for 15 mins or so with no luck. I sat in the car for another 10 mins without trying then finally tried one last time and it immediately fired right up. As if nothing was ever wrong! From there I drove it to the office without any issues.

I drove home without any issues at all and again, it performed FLAWLESS. After I parked it in my garage I tried to start it again and again, it won't start. I waited 30 mins and tried again. BANG! No problems, fired right up!

In conclusion, when the car is hot it won't start. It tries to start but sounds as if I'm out of gas (I'm not).

Any ideas or thoughts here?

Thanks!
Jay

[Ron]

I'd see if it was throwing any codes. If not, I'd pull a plug wire and see if it had spark. If so, try a short shot of ether to eliminate fuel delivery...

[nofear365]

The only code I have right now is P440 which translates to Evaporative Emission Control System Malfunction

Not sure if the 2 issues are related but my guess is they just might be!

[Ron]

Not likely, that is a code for the pressure in the fuel tank (bad cap, hose, canister broke, etc.)

[Rich]

This Jag's hot-start failure symptom is very much like what PRV engines suffer if there is a fuel rest pressure retention problem.

Rock Auto parts catalog says that '97-'02 XK8s have a Fuel Pressure Regulator in the FI system.

A quick look at a Jag forum thread for this problem on this car suggests that the FP regulator or the fuel pump check valve might be faulty. In any case a rest pressure retention test is in order.

Check post #4 for a good description.
Link:http://www.jaguarforums.com/forum/xk8-xkr-17/what-does-fuel-pressure-regulator-do-43297/

The Jag regulator is not the same thing as a K-Jet accumulator - the Jag regulator is a high-pressure bypass valve - but if it leaks when it should be closed or if the fuel pump check valve leaks shortly after the engine is turned off then the fuel rail pressure will drop and the fuel can vaporize leading to hot starts that get longer or are impossible til the engine cools down.

[DMC5180]

+1 on the FP regulator. Had something similar happen on our Cadillac. In my case it was leaking into the vacuum port and causing slow starting. More cranking than normal.

[pezzonovante88]

Have you tried going on jaguarforums.com?

[nofear365]

Sure have. I'm a regular member there as well. However, no one has provided as good of a solution as Rich has.

[pezzonovante88]

Sure have. I'm a regular member there as well. However, no one has provided as good of a solution as Rich has.

Nice. I've found that that forum is nowhere near as active as this forum. Anyway, good luck with your Jag.

[Rich]

Sure have. I'm a regular member there as well. However, no one has provided as good of a solution as Rich has.

Well, half of Rich's info came out of the link in Post #5 to jaguarforums.com, so everybody's a winner on this one! - Rich

[nofear365]

Nice. I've found that that forum is nowhere near as active as this forum. Anyway, good luck with your Jag.


I agree. It's a nice forum but I don't get the impression that many pop the hood and diagnose their own issues. Quite a few posts begin with "So I'm taking my Jag to the dealership tomorrow..."