Starting Question

I have a 92xj 4.0. When I bought it the exhust manifold was cracked so I took it off and welded it up. Put everything back together and all was great.
About a month after When I go to start it the first time you turn the key it will crank and crank but won't start.I turn the key off then back on and it fires right up . It aways starts on the second time and run's great . I was just wondering if any of you have the samething.And if you did what you did to fix it.
Thanks

Next time try this: turn the key and listen for the fuel pump running then stopping. Turn off and repeat, and then crank. If it starts right up, it's probably the check valve in the fuel pump. You can fix it (new fuel pump), bypass it (I believe some people have spliced a check valve from a BMW into their lines) or learn to live with it by prerunning the pump a cycle or two before cranking.

It may not be that bad.... I used to have a '94 with the same symptoms, and fixed it by running a (good) injector cleaner in 2 successive gas fillups and changing the plugs. It's worth trying, and a lot cheaper than a pump.

Ok,I have the same problem and I want this mysterious bmw check valve!!!! Someone give me the part number please!!!! I've done a bunch of searches and emailed people but got nothing. Thanks all!!!!

First I've heard of a BMW check valve but Currie is right on the money.

More than likely your fuel system is bleeding down pressure. A fuel injected engine needs starting pressure to stay in the fuel system so the engine starts right up the first time. Your XJ should run on about 35 psi. A good fuel pressure gauge is always an asset to your toolbox. Hook up a fuel pressure gauge to the fuel rail. Start the engine and see where your fuel pressure is. Then turn it off and see if the pressure bleeds down. It should stay at operating pressure for at least 30 seconds or so. Then only drop a few psi.

If it drops rapidly it is very likely the check valve in the pump is leaking back down inside the tank. Another thing to look at is the fuel pressure regulator. When fuel pressure leaks back down pull the vacuum hose of the fuel pressure regulator on the rail. If there is ANY fuel in the hose, or leaking from the regulator itself replace it. A lot of chrysler built vehicles use returnless fuel systems now with the regulator inside the tank mounted on the fuel pump assembly. If you only have one fuel line going to the fuel rail this is the setup you have.

Another possibility is fuel injectors. Build pressure in the fuel system again and watch the gauge. Clamp off both fuel lines. There should be a rubber hose section somewhere in the fuel lines going back to the tank. (carefull here not to damage the fuel lines) Once clamped off to prevent fuel flow back to the tank see if pressure still drops down. If it does your problem is not the check valve in the tank, but forward of where your clamps are. Injectors or fuel pressure regulator. The tricky part is figuring out which injector is leaking. Pull the spark plugs and see if any of them are wet with fuel. Find a wet one and there is your problem cylinder.

HTH

I have an 87' (offroad only use now) and it does the same thing I say just live with it unless it really bothers you that much.

Thanks guy's
I'll check out the fuel pressure and go from there.