Got a head scratch-er here fellows.
6.0 ambulance. JASPER REMAN engine. Customer reports an intermittent no start hot.
I have a P2291, P0528 and a P0620 in continuous memory.
Hot IPR is 24%, wide open throttle IPR is 59%.
With oil temp at 195 or higher, IPR ramps to ~30 percent and truck fires up. Every time.
Air check reveals nothing.
I've not yet been able to get this thing to no-start, but I'm hesitant here, since I do have a 2291 and it is an ambulance.
A local dealership has shotgunned an IPR at it, and apparently the concern persists.
I'm scratching my head on this one.
The only thing I came up with and this is a LONG shot, but what if the ICP was feeding faulty info to the PCM? Will the ICP reading of less than 500 PSI cause a no-start, even if the actual pressure is over 500psi? I know when the ICP is open circuit it will substitute values and start anyway, but I can't recall or find documentation that says if the ICP bias is incorrect if the vehicle will actually not start.
Any ideas guys?
Thanks!