Starting Problem

[QwkSlvr97LSC]

Be forewarned: I'm a newcomer!

After wanting a Mark VIII since late 1992, I finally have one. I'm fairly experienced with 5.0 cars (and others) but the 4.6 is new territory. My car has 114,000 miles and a few problems. The most annoying is a starting problem. Sometimes it fails to start without using ether. Once it fires with the ether, it runs fine. I have a fuel pressure guage on the fuel rails and it reads fine with no fluctuation. I changed the temperature sensor in the intake with no effect. The problem occurs after the car sits for at least an hour. However it is very sporadic. Weather or temperature has no affect on it. Most of the time it starts fine, but the problem surfaces from time to time. To me it acts as if the injectors fail to spray during cranking. Has anyone experienced or heard of this? Any help will be greatly appreciated. I have to take care of the bugs before the mods begin!! Thank you.

[Mike 09MKS]

That's a lot of Miles for a 1997, I've only got 32K on my 1998. The engine is usually a strong point on these cars, I'd get a code reader and see if anything is showing there.

There is the crank position sensor also, good for an ignition problem anytime.

[bill_s]

My 92 TC was a hard start when hot. Apparently there is enough of a leakdown in either the regulator or the pump so that the fuel rails go dry when hot. Fixed this with a primer button that turns on the fuel pump. You can hear the pump speed drop when the system achieves pressure after a few seconds, and the engine starts instantly.

Try running a wire from the PCM side of the fuel pump relay coil, and ground this through a pushbutton to prime the fuel system. If this doesn't work, at least you have eliminated one possible cause of the problem.

If you wrap a wire around the low-voltage wires to a coil pack, and the other end around your radio antenna, and tune between stations on the AM band, you should hear the spark noise as soon as you start cranking, if the ignition is good.

A 1/4" plastic tube with one end in your ear and the other up against an injector will give you a clicking sound if these are being fired.

Have fun, and welcome to the wonderful world of electronic everything. Let us know what the trouble turned out to be.

[Avu3]

Another part that fails and can cause problems is the crank position sensor.

They are pretty easy and inexpensive to replace.

Not sure about the ether part, though. Usually the CPS just won't start, period

Scott