2002 7.3 /w 150k miles
Stock computer, stock programming
Since I've owned the truck (~1 year, less than 5k miles) I've changed the injector o-rings, glow plugs, added the Ford connectors to keep the under valve cover harnesses from coming loose, added dieselsite coolant filter and trans filter kits, also replaced the ICP (last one worked but was oily so got a new one from Ford).
It has shell rotella t6 (5w/40), about 3k miles/9 months on it. Fresh tank of diesel from a big rig truck station. As mentioned, I did all 8 glowplugs and injector o-rings last year, and it has a new ICP. It hasn't used a single drop of oil, no leaks, no oil consumption since the last oil change 3k ago. Definitely no oil in the valley.
I don't drive it very often, but for the last few months, I've been fighting an intermittent hard/long/no start issue. Once the engine is warm, it runs fine, but has trouble catching/staying running when the engine is cold. Sometimes it will just crank and crank and crank. Sometimes, it just takes a little longer than I think it should to start. Today, I got in and fired it, and it sounds like it was misfiring badly - loping, having a hard time catching idle, smoking out the exhaust. If I let it warm up, it runs like a champ.
I've been trying to follow this as a guideline:
I have been using a Snap-on Solus scanner to scan it when its acted out, and ONCE the scanner picked up a P1212. It never threw the CEL, but the scanner popped the code. That doc says:
P1212 sets if 725 psi of ICP is not detected in 6 to 15 seconds of cranking.
I don't have the tools to plug each head and watch ICP, but since I changed all 8 o-rings recently, my gut is that its not specific to a head.
When its acting fine and warmed up, IPR% is ~8-10 at idle with 475psi ICP. WOT, 38% IPR and 2800psi. Today when it was cranking and having a hard time starting, I was scanning the IPR% was pegged at 65% and ICP was 375psi. After a few seconds of that, it caught and loped, missed, etc, and the IPR was jumping high, trying to raise the ICP.
The bugger is, its intermittent, and once the truck is warm, its fine. Maybe takes a tiny bit longer to start than it did when I bought it, but always fires catches and idles clean when warm. The doc seems to say that because can't build pressure, I've got a leak somewhere in the system. But how can a leak be intermittent? Sticky IPR?
I was thinking HPOP or IPR (perhaps new o-rings on the IPR). I just don't know where to look since its fine when warm, and sometimes fires fine when the engine is cold (although its more often bad than good nowdays).