7.3 just started doing a long crank to start

[mrproffitt]

My 99.5 250 hp 7.3 has just started doing the long crank issue. Truck has always started on the second to third time the engine turns over. Now its 8 or 10 times before it starts.
I went to the store and it started fine, went to leave store, and it was 8-10 times and has been that way for a week now. I replaced the IPR o-rings, new Airtex lift pump and fuel filter. I'm thinking it has to be something in the low pressure or high pressure oil system.
The truck has always started 2nd or 3rd time spinning over, 18 or 118 outside, engine hot or cold for days at a time. The truck has 174000 miles, no codes set. Truck runs fine after starting. I don't know what has changed in between those two trips 15 mins apart. Where do I need to start.

[jesilvas]

It was hot that second time you went to start. The engine that is. IDM maybe.

[mrproffitt]

It does it hot or cold now. Same amount of revolutions. Tach shows approximately 300 rpms when cranking. Disconnected the ICP and the truck runs rough until throttle is moved and lack of power. Disconnected the Oil Pressure sensor with no start. Disconnected the Oil Temp sensor, no different in starting. I have yet to see any post on any site that tells how they fixed a Long Crank or Hard Start issue. I have found several post like mine with the long crank and no answers on any of them. It would seem to me that something has broken I.e. o-ring, sensor, check valve or the like.
The engine set some funny codes too. P1249, P1670, P7A00, P68C3, P79FC. I know what the 1249 and 1670 are, my wasegate controlling valve is bad. It sets there and pulses open and closed so I disconnected it years ago. What are the other ones? They showed up after I disconnected the sensors?

[SHANE M]

I don't know the fix but I can tell you I am having the same problem but mine started differently. My truck has trash/water in the bottom of the tank and when it gets down to about 1/4 tank or lower it starts running rough. Well one day it died at a quarter tank. I put fuel in it and it would not start so I towed it home. I filled it up completely with good fuel and it still would not start so I changed the fuel filter. After I changed the fuel filter it started and ran rough so I let it idle for about 30 minutes. After that it has always started up fine but it has to turn over 8-10 times when before it only took 2-4 times. I had a 24V CTD before this and it would literally start on the first turnover so it frustrates me to have to wait so long for it start. I know it is hard on the batteries and starter to have to turn over so much.

[Fireman40]

How many miles do you have on your oil? When my oil gets to the end of its life i get the same thing. It cranks for a little longer to start. The oil gets really foamy and it take alot of oil pressure to run the injectors. I think the oil breaking down just takes more to pump the injectors. As soon as a change my oil, im back to starting right up. Just a suggestion

[mrproffitt]

Well, its almost been a year since I started this post and still no answers. I have replaced the ICP sensor, IPR valve, and just installed an SRP-1 HPOP today and there is still no change in the long crank issue. My truck has 1900012 as of today and a co-worker has a 97 with 230k and his starts faster than mine. Does anyone have any ideas on what else may cause the long crank issue?????????

[mrproffitt]

I also replaced the fuel pump with an Airtex unit months back, did the fuel filter plunger delete mod in the fuel bowl. Replaced all injector O-rings and glow plugs with Diesel Site plus the GPR. I'm now looking to start pulling the heads to get to the drain back check ball and possible IDM.

[jesilvas]

It could be the anti drain back check valve in the HPOP reservoir?
I mean unless it keeps it from starting fully, I wouldn't worry about it too much personally. It'd still bug the heck outta me though.