Hard starting issue

[sleeper1]

My truck decided to not start today all of a sudden. I hooked up my laptop to check the truck with Auto Enginuity and I couldn't come up with anything. The ICP numbers were about 640psi, no codes, and everything checked out normal. I tried cranking it multiple times and it started. My friend suggested it might be a cam position sensor so we put one in. It started fine three times in a row. We went for a ride a little while ago and it had the same hard starting issue. The key to getting it started was short cranking time rather than long. Anyone have an idea what could be causing this this?

[dazdillenger]

Fuel pressure check out? When you say short cranking, do you mean crank, turn key off, then crank again? That would build fuel pressure by cycling the pump.

[sleeper1]

Yes I'm getting fuel pressure. I have my gauge hooked right to the upper fuel bowl. What I mean by short cranking is turn it over for a few seconds, off for a few, on for a few until it starts. When it does it starts weak and stumbles for a few seconds then idles normal

[sleeper1]

I should probably mention that after I changed the CPS I got a code for the crankshaft position sensor circuit being open or something. I cleared it and it hasn't shown up again. I've also been getting a code for FICM performance after putting in a tuned one from Power Hungry Performance. I'm not sure if this is normal or not for a tuned FICM. Every time I clear the code, it will eventually come back. FICM power reads 48V though. Figured this info might help.

[dazdillenger]

Truck can throw a cel for cps anytime it cranks for an extended time and doesn't start. Monitor the FICM SYNC pid while cranking-it should switch from "NO" to "YES". When its trying to start does the IPR duty cycle rise above 14 percent?

[sleeper1]

I just went out and checked the FICM SYNC. It did go to 1 when cranking and the IPR DC went a little over 20%. The truck didn't start hard though. I started it about 5 times and it was fine. This seems to be a problem only when its hot. I know someone wants to tell me its a HPO leak, but like I said, the ICP numbers were good. I replaced my injectors about 3 weeks ago and had this same problem for a few days after. Initially I thought it was a HPO leak because it also only happen when hot but I haven't had the problem since this morning.
When I just checked the truck, a few codes came back. They are p2614 and p2617 which are camshaft and crankshaft position output circuit open.

[dazdillenger]

when it doesn't start monitor ficm sync, and ckp, cmp sync. They should either say YES, or 1. The fact that your ipr duty cycle moves off of 14 means they are communicating. Did you check cranking RPM with the AE?

[dazdillenger]

what is your ficm voltage, both cranking, and key on engine off? if it dips below 48 (give or take a volt or two) replace it.

[sleeper1]

I haven't checked cranking RPM. I will have to drive it around to get it hot and try to get it to not start again. I will monitor these things tomorrow when I have some more time. Thanks for your help tonight and I will get back on here with the results.

[sleeper1]

The FICM is at 48V KOEO and drops to 46V when cranking. I'm probably going to switch out FICMs again tomorrow just to rule it out but like I said, I was having the same problem right after I did my injectors and that was with my other FICM which was replaced by Ford about a year ago.