found this on Pg 13 of the xk technical guide. maybe it'll give you some ideas

 

Thanks Matt, but I think I can declare this problem solved. I just drove from NC to Florida and back with a couple of days at Disney mixed in. I didn't have a single starting issue the whole time. I the original problem was solved with the installation of the check valve, and the no-start problem must have just been due to air in the fuel line from the filter replacement.

 

Would a new fuel pump have been the 'proper' resolution? I suspect a dealer nor an indy would have installed a backflow preventer.

 

Yes, the fuel pump apparently has a built in check valve to keep pressure on the fuel line and prevent the fuel from draining back into the take when the car sits without running for several days. The check valve on my pump was apparently bad. Rather than go through the whole process of removing the fuel tank and replacing the $500 pump, I just inserted a $35 check valve in the fuel line at the point where the line comes out of the tank.

The 1997 through 2002 model year cars used a different pump, and those can be bought for less than $100 online. The 2003+ model years use a different pump which is more expensive. I didn't want to spend that much on a pump, and I didn't want to go through the hassle of removing the tank. My "rigged" solution was cheaper and easier, but I can understand that some people may scoff at my "chewing gum and bailing wire" solution. But hey... My car starts with no problems now, and that's all that matters to me.

 

Once again, nice job Sam and thanks for sharing your results with the forum. In retrospect, is there some other location along the fuel line that would have made it easier to install the check valve where it would still have adequate protection from the elements?

 

I wondered about that myself. I assumed that it should be as close to the fuel tank as possible, but after I had cut the line and I was working in an awkward position with no space, I started to wonder if it would have worked just as well on the long straight stretch of easily accessible fuel line between the filter and the engine bay. I guess I'll never know the answer to that. If I had to do this over, though, I think that's where I'd put it. I probably could have done the whole job in 15 minutes if I had installed it there.

 

I had developed a fuel leak at the check valve because of the way I installed it. I hadn't removed enough of the hard fuel line and one of the two pieces of flexible hose I had used to connect the check valve to the fuel line was bent at a weird angle. This caused the hose to leak. I then discovered that the fuel line and check valve I installed are EASILY accessible just by removing the left rear tire (I could have kicked myself when I realized this). It is soooooooooooo much easier to access it this way. I can't believe I worked so hard at installing the check-valve from under the car when all I needed to do was take off the wheel.

Anyway, the attached video pretty much shows everything you need to know if this problem happens to you and you don't want to tear out the whole fuel tank.

Here's the VIDEO. It's only 6 minutes long.

 

Oh yeah... to Oldmots. When I read your post about the band clamps a couple of months ago I was thinking "there ain't no way I'm gonna mess with that again unless it breaks". Well, now that I see how easy it is to access from the wheel well I'm going to get some of those clamps you mentioned and replace the ones that are currently installed.

 

2001 XKR 50K miles. Ok if I parked my car with the fuel tank full at a slight incline nose down the car after being left a day or so starts in 2-3 sec if I parked it with nose slight incline up it takes 4-5sec to start. So I fitted a 3/8 fuel return valve. I used the one mentioned earlier and I didnt use the rubber hoses I just spent 5min with a file to file the first 1/4inch down so that I had a tight fit into the value. I also use the nylon washers which can easily be file to fit the pipe. Worked great and fits really neatly between the clamp and the curve under the back wheel.

Only problem is still takes 4-5 sec to start and sometimes it makes an awful noise that comes and goes, sounds like cavitation in the value when running !!

And b4 u ask not leaks and the value is in the right way round!!

I will be removing it once I get the fuel tank back to empty.

Any ideas????

 

On the 2002 and earlier model years, there are two lines, one line carries fuel from the tank to the engine, the other is a return line that carries excess fuel from the engine back to the fuel tank. Are you sure you installed the check-valve on the correct line?

 

yes it on the thickest of the 2 i.e 3/8th the return line is way thinner and on the inside. I can get u a pick if u want

 

FINAL UPDATE!

I give up. The inline check valve apparently doesn't work on the newer XK8's which don't have a return line to fuel tank. I was continually having a problem where the pressure would build up between the fuel rail and the check valve after engine shutdown. For some reason this pressure prevented the car from starting. I could connect my OBDII tool to the car and see that during normal operations the pressure was around 380 kpa, but once I shut off the car it would go up to 500 kpa. Eventually the pressure would bleed off and I could restart the car, but that would take a couple of hours. I discovered that if I took the decorative shroud off of the engine and vented some fuel from the schrader valve on the fuel rail I could start the car instantly, but if the pressure was over about 400 kpa the car would just not start. I'm going to go back and edit my first post to warn others not to try this unless they are driving a pre-2003 XK with a separate return line to the fuel tank.

I've removed the in-line check valve so now I'm back to cranking the car for 8-10 seconds before it finally starts. I am going to try one more thing before I pull the fuel tank to get to the fuel pump. I'm going to take a file and put a little notch in the little plunger within the check valve that prevents the fuel from flowing backwards. I think if I give the pressure some way to bleed off back into the tank the car should start properly. The key will be to make the notch big enough that it allows the pressure to bleed off, but not so big that it lets the fuel drain away from the fuel rail above the engine. If that doesn't work, I'll just replace the fuel pump (I'm not looking forward to that, but it would make a good video ).

 

OK, looking forward to seeing it , have a good repair

 

Sam, not sure it is relevant or not, but I came across this Hard Starting XK8 Diagnosis TSB when I bought one hour of time on Topix the other day. Have you checked your tank pressure control valve (TPCV)?

 

I just looked through the JTIS and I don't think the 2003 model has a tank pressure control valve. At least I couldn't find it in the JTIS. Starting in 2003 they changed the fuel system and eliminated the return line. I sure wish the TPCV was the problem because that little piece would have to be cheaper than a new pump.

Anyway, some people will scoff at this, but once again I think I have fixed my problem. Last night I took the check-valve apart. It has a tiny little O-ring in it which seals against the body of the check valve to prevent fuel from flowing backwards. The O-ring is seated in a brass valve and the valve/O-ring assembly is spring loaded so that when fuel is flowing one way the spring allows fuel to pass, but when fuel flows the other way the spring pushes the valve closed.

Soooo (here's the part where people will scoff) I cut a little notch out of the O-ring so that it can't seal completely when the check-valve closes. After installing the check-valve back into the car I hooked up my OBD tool and watched the fuel pressure. With the engine running the pressure was about 380 kpa, and when I turned off the engine I could see the pressure spike and then start to decline. That's exactly what I wanted it to do since the overpressure is what was apparently preventing the car from starting.

This morning I went out to the garage and the car started instantly! So the notched O-ring did not allow all of the fuel to drain out of the line, but it is allowing the pressure to bleed off. It appears as if everything is working the way I want it to now! However, I wonder how long the damaged O-ring will be able to hold up with the high-pressure fuel blasting past the notch every time I turn off the engine. It's upstream from the fuel filter, so the worst case scenario is that the O-ring breaks and gets caught by the filter. Then I guess we'll see if the brass valve by itself has the ability to prevent the fuel from draining back into the tank. If so, then I'll never even know that the O-ring broke. If not, then I guess I'll try plan 5.

 

I like the fix, whether it is temporary or not. If it lasts a year, that's still a win in my book.

 

Sam, your attitude is an inspiration to all. I enjoy reading your adventures; Keep it up!

 

Thanks, Spurlee. Unfortunately I think the O-ring has already been blasted into the fuel filter. My long crank times have returned. It's only taking 5 seconds or so now, compared to the 10 seconds it was taking. But still, I don't want to be parked next to a BMW while starting my car. The BMW driver will laugh at me. I guess I'm just going to have to bite the bullet and pull the tank out.

 

Reverend Sam - what did you decide to do with this issue at the end? Did you get the pump replaced or do you just do the wait-to-prime then start the car?

Mine develops same issue like yours - very long start/crank - which can't be good for the ignition system. I usually just turn on the ignition, wait until the 3rd beep, turn it off - then wait 5-6 sec before starting, which works 100% of the time.

Maybe I should do a pressure test as the next step ..... The fuel pump replacement cost - based on what the forum members have posted, and indy/dealer quotes hover around $1400 .....

The good thing is - I've kept some $ every month for repair/maintenance funds. The bad thing is I may end up using half of that funds ....

 

I have no solution. I still have the long crank times.

The thing I find confusing is that if the alleged check valve in the fuel pump was bad, then wouldn't the fuel system have to have a point at the front of the car to allow air into the system in order for the fuel to drain out of the fuel line and back into the tank? Let's pretend that the fuel system is sealed from the tank up to the injectors; the fuel couldn't drain back, it would just act like a hamster water bottle and the fuel would sit there in the line.

This would be much easier to figure out if I could find a diagram of the fuel system somewhere. One does not seem to exist. There's not one in the JTIS, and a couple of hours of googling didn't reveal one. I even googled on bing.