Check engine light and flashing wait to start light

[Kshow]

97 7.3L PS, tried to start this morning, check engine light and wait to start light flashed continuously ran like hitting on only half the cylinders then stalled. This has never happened before. GP relay has been replaced and i know glow plugs need replaced. Have had no starting problems this summer. Talked to garage they had no idea. Did say the flashing wait to start light was very odd. Came home from garage tried to start truck again same thing, then smoothed out it ran fine. Any ideas? 120K on truck.

[Andy]

That is very odd. Do you have some kind of a power programmer that you use on your truck that also does diagnostics? The Edge Evolution, Superchips Microtuner, and Diablosport Predator all do diagnostics.

Lem

[Kshow]

nothing, completely stock.

[WV Hillbilly 97 superduty]

I have a 97 F250 and I think I know what it is. The resevouir where your fuel/water seperator installs is also a prewarmer for the fuel. If it only does this on cool days and only after it has thoroughly cooled down I would say this is it. Try and plug it in to electric and see if it start ok the next morning if it does this is it.
My truck started that last year and the mileage is similar. I held off replacing it since its over 200.00 plus labor.

[wesjones]

right about the separator, you might want to drain it off a little, although fuel water separator issues are supposed to illuminate the water in fuel light...as for the wait to start, the glowpugs may be bad causing the light to come on, but the glowplugs aren't causing the engine failure...

[WV Hillbilly 97 superduty]

I thought it was the glow plugs too & had them changed. Problem is the heating element in the fuel water seperator has died. If I don't plug in and it gets into the 50's I have to cycle the glow plugs 5 times b4 it starts. It idles very rough and puts out plenty of smoke for a few minutes and then it smoothes out as the engine warms.
PS. The colder it gets the harder it is to start if you get it started.

I am replacing mine before we get snow in December.

PSS Watch your water pump they start leaking around 120-140k

[deerhunter338]

I had a very similar problem with the wait to start and the check engine flashing. I checked all connections and had no luck. Finally I just pushed down on the relays under the hood on driver side. I had my wife turn the key and it started like normal. One of the relays just had a bad connection in my case.