Hard start - FICM sync issues

[SteveH01]

I am experiencing hard starts whether it is hot or cold. When I first start cranking I do not have any FICM sync or CMP/CKP sync. As soon as both sync the engine starts and runs fine. Sometimes I have to crank 3 or 4 times before it syncs. When cranking, the HPOP pressure jumps to 800 and continues to increase after that. FICM volts are 47.5. Cranking RPM is 125 - 150. Also after it starts the CMP/CKP sync goes on and off every 1 second or so although the engine keeps running. The problem seems to be getting worse although I can eventually get it started as long as the batteries hold up.

Is it safe to assume that the camshaft position sensor needs to be replaced? Or should I be looking at a wiring issue?

[bismic]

Any codes ?

[stewcon]

Replaced my FICM because the truck wasn't running smooth. Tech said that the FICM needs 48 volts to operate correctly(mine was at 37 volts). The truck ran like a new truck after that, and still does. Replaced at 112K and now have 140K on truck.

[SteveH01]

The only code I have is P0603 - PCM KAM error. I put new batteries in a week ago so this may be a result of that.

[SteveH01]

I fixed the problem! Over the last several days the cranking RPM has been dropping. It was 125 to 150 when I first encountered the problem and finally got to around 100. Finally the starter failed completely. Replaced the starter and it started up on the first crank. Cranking RPM's are about 250 now. I have heard that the minimum RPM is 100 for FICM sync, but my experience indicates that you need more than 150 to get consistant FICM sync. The old starter was probably pulling high amps as it was failing, but FICM volts were always 47.5.

[bismic]

Thanks for posting the conclusion!