I hope you can help me. My 2005 XJ8 has recently developed a problem. When I start the engine, it runs for only a few seconds and then dies. This happens over and over. No DTC codes came up when I ran a scan. Another thing, I wanted to put a fuel pressure gauge on the car, but there's no Schrader valve on the fuel rail. Does anyone know how I can read the fuel pressure in this case? TIA

 

with a scanner

 

No DTC codes came up when I ran a scan.

 

Use a smart phone with the Torque app to connect to the vehicle's PCM via the OBD port with a Bluetooth interface to read fuel pressure and other functions in real time.

With the ignition in the ON position there should be around 3 bar (300 kPa) of fuel pressure prior to engaging the starter motor.

 

NBCat - Thanks!

 

My question is whether this is all the time or after you have run it somewhere and shut off. I had this happen to me a number of years ago. Car would start and run fine. Go to the store and then it wouldn't run when I tried to restart.. Always would start but then die. I would have to force throttle for several minutes until it cleared out. Never any codes. Ended up being a winter fuel blend issue. See attached TSB

 

jluvzcarz - This was a one-time occurrence. It didn't happen following a drive. When it happened, the car had been sitting in the garage for a few days. I tried to throttle it but it would stall after a second or two. Never had any such problems with the car during the last five years of ownership. Thanks for your suggestion and the TSB.

 

While this veers sharply off the OP's post, I have also been running into the hot start issue, as described by jluvz and in the TSB. While on vacation in the southern US last week, I was able to isolate the issue to E10 gas--I ran through three tanks of premium fuel with no ethanol added, which worked well and gave me no issues on hot starts.

Since getting home from last week's trip in the Jag (close to 2000 miles last week), I was able to plug in both the battery charger and the laptop this afternoon, and worked through the process in SDD, as described in the TSB (I'm running SDD V159 and a clone Mongoose dongle on Win7). The process took about 20-25 minutes, and the car restarted, no problem. I have some running the state to do this afternoon--250 miles' worth, so I should be able to test out the reflash after a couple medium-length stops between highway drives. Fingers crossed.

Paul

 

paulz67 - That's interesting. Where did you have problems with E10 fuel? Was it while you were in the Southern US or did you run through three tanks of premium while there? Please update us following your 250 mile drive.

 

Canuk I think you said that you can start the car several times in a row but that it won't stay running. If that is true then it would seem to me that you are getting fuel to the rail and that there is not a spark problem. It is going to maybe sound crazy but could the ignition switch have failed to where it won't work in in the "run" position.

Have you tried starting it and possibly jiggling the key a little once released to see if it affects whether it stays running or not.

I am only throwing this out there as you say there are no codes showing, so ideas like the TPS, IAC, MAF etc don't seem plausible.

 

jluvzcarz - Not crazy at all. That makes sense. However, when I released the key and it returned to the RUN position, the engine didn't immediately die; it continued to run for about two seconds.
Now, it gets crazier... I finally gave up and made an appointment with a local indy Jag specialist garage. A flat bead car hauler came to pick up the car. The driver placed the car in neutral, pushed it back, and hooked up the chains to pull it onto the truck. He got the rear wheels onto the truck and stopped winching to double-check underneath. I asked him to try to start it again (for the hell of it). He turned the ignition key three times. First two times, the engine again stalled after a second or two. On the third attempt, it fired right up! We unchained the car and he waited while I test drove it. No problem. I've driven it ever since without any issues. Go figure! I'm completely stumped.

 

Now I'm thinking fuel filter or that the fuel pump itself is getting weak or both. Maybe changing the angle of the car as it went up on the ramp dislodged some debris blocking the fuel filter or even the screen on the pump in the tank. Fuel filter would be a low budget easy job to try especially if you have never had it done.

 

jluvzcarz - I checked the fuel pressure a few times while the problem existed. Key on before starting the engine: 47 psi. Right after starting the engine (before it would stall): 54 psi. I replaced the fuel filter at 65,000 miles. the car has 73,000 miles on it now. It's been running like a dream since the problem disappeared. It has me baffled.

 

Well if you ever come up with an answer I would be interested in what it ends up being. There is another post in the XK8 section that I read recently that started out similarly. He had spent thousands and never has figured it out. Very strange.

 

jluvzcarz - I think I'll keep my money in my pocket and hope that it never happens again! I already paid for a rental car for two months.

 

From the description in post 11 above, there could be some foreign object in the fuel tank that dislodged whilst the vehicle was at an angle on the flat bed recovery truck.

 

I just wonder if by putting the car on an incline it somehow helped an air pocket finally move through which might have been confusing your pressure readings and pump operation.
I think the XJ8's are like the X-Types and don't have a fuel return line, so any air that happens to get into the system has to eventually bleed out via the injectors unless you have a Schrader valve on the fuel manifold that you can operate to clear the lines.

 

h2o2steam - No Schrader valve on the fuel manifold. I suppose your theory might be right, but I would have thought that after all the attempts to start the car over almost two months any air pocket would have been dislodged or purged through the injectors. What do you think?

 

Bill,

Sorry for the delay in responding. To clarify: While on vacation, I started out using E10 fuels for the first 500+ miles of that trip, and did have warm start issues. Once I switched to E0 on the trip, there were no warm start issues. I stuck with E0 for the rest of the trip back home.

The ECM reflash apparently wasn't fully successful the other day--I didn't have a stout enough 12V external power source connected to the battery. In the test the other day, I couldn't duplicate the conditions that show up (long drives, heat soaked for 20-25 minutes, then attempt restart) until I got home from that quick 250+ mile trip. Once home, I was able to duplicate the conditions and unfortunately that's when I figured out the first attempt was not a success.

Yesterday, I dug out another power supply that puts out substantially more current (Jaguar is NOT kidding when they suggest 30++ amps of current from a charger/supply; a 20 amp 12V supply is marginal!), and repeated the reflash process yesterday. I haven't had a chance to go for a drive and test things out, and I'll update again when I do, hopefully later today.

Paul

 

Paul

Good luck with the reflash. It takes quite a bit of current at 14.2V to keep up with that. Please let us know the outcome.

Bill