2003 7.3 PS. 175,000 miles, purchased used at 47,000 miles.

Repairs: made fuel filter drain valve in last 7 days.

Alternator 1.5 years ago, AC centrifugal clutch and batts. Regular oil changes and coolant flush and trans flush. Last fuel filter change was within 7,000 miles.

Got the real cold weather three weeks ago. Started truck and came out to 4' diesel puddle underneath. Knew I had a leak for a while coming from valley. Slow oil leak for months prior, thought it was rear main but it is from valley.

So I've replaced the filter drain while bowl on truck. Fuel leak stopped. During this time I could see what looked like atomized fuel spray During WTS and cranking from back down below cold side turbo in valley recess. I have not seen that since replacing drain valve.

However, the truck periodically either won't start or is hard to start. I can hear the fuel pump running and I get a regular WTS. Crank and crank but it acts like no fuel. Then it will burp start and die. Might do that several times. Plunge the pedal sometimes and it will crank to life. Get a big puff of smoke briefly but only when it finally starts up. I do feel there is a miss more now than over a month ago. Seems a rougher idle. Hard start is not an everyday thing and when cold only.

Never done a CPS on this.

The oil buildup on the piping under turbo and bottom of turbo piping has increased in last 3 mos.

Fuel usage seems increased for 6 mos but that may have been the fuel drain valve.

Oil use is about standard and I'm running full syn delo this round.

 

Also, once started, smoke disappears and high idle works fine. In my mind it seems down on power but that may be just psychological issue.

Also, the oil level cold on stick just a few hours ago was maybe an 1/8th below bottom normal range indicator.

 

This sounds like a problem with the glow plug system to me. Have you ever replaced the glow plug relay?

 

No GPR replace. WTS cycle operates normally.

 

The WTS light doesn't really mean anything with regards to whether the GPs are actually working or not. It's just turned on by the PCM for an amount of time based on temperatures. Unless you have a CA emissions package, the only way to know if the GPs are actually working is by testing the system at the component level.

 

Fair enough...no CA emissions. Learned something new on the GPR and WTS cycle.

How to test at GPR component level?

 

Try to cycle your GPs twice for 30 seconds and see if starting is improved. You should still check the GPs obviously. As indicated the WTS light doesn't mean crap, just because it shuts off doesn't mean your cylinders are warm enough. The GPs can stay on up to two minutes after you initially turn the key to on

 

Take a multimeter and make sure you're getting the same voltage as the batteries to the outer large post on the GPR (the rear relay if there are 2 of them). Then turn the ignition to ON and immediately check the voltage on both the outer and inner large posts. The voltage difference between the two readings should be minimal. If that checks out ok, the relay is good. If there's a large drop, or no voltage on the inner post, the relay is probably the culprit.

If the voltage is good, you can check the individual GPs by checking the resistance through the valve cover gasket connectors. The front and back 2 pins on each gasket are the GP pins, and correspond to the cylinder positions. Testing between those pins and ground should be somewhere between 0.6 and 2.0 ohms

 

Did you ever figure out where the oil in the valley was coming from?

Oil around the CAC boots & pipes is normal, but could indicate minor boost leaks. This isn't causing your hard starts, but if you're interested in checking for leaks you can make yourself a detector. Here's a video:

These guys have you squared away on the glow plug system. Seems to be caught red-handed here. When you say acts like no fuel, you aren't getting smoke from the tailpipe?

 

Correct. During all cranking there is no smoke from tailpipe. The moment it compresses fuel and starts running there is a billow of smoke that follows. Then no smoke and it idles normally. Once warm that does not occur again the rest of the day.

 

I'm wondering if you're losing HPO prime into the valley. Are you still having that oil leak into the valley? You could check HPOP oil level by removing the plug atop the reservoir before the first crank in the morning. Should be less than 1" from the top.
Loss of prime could cause hard starting and air introduced could cause a rough idle and power loss.

The "only when cold" thing leads one to think GPs, or fuel restriction. Can you verify fuel pressure after an overnight cold soak? You can open the drain valve, turn the key on and note how fast fuel comes out. You should attach a hose to the drain tube or be ready for a mess though.

I'm just floating ideas. It's still definitely worth checking your GPR and GP resistance at valve cover harness.

 

When first I read your post, I thought you meant you were seeing what looked like atomized fuel while cranking from the exhaust. If you aren't seeing anything from the exhaust, it probably isn't getting fuel to the cylinders. It certainly won't hurt to check the glow plug system, but now I'm thinking more along the lines of IPR, or something else to do with the high pressure oil flow like t.scottNDU mentioned above. Next time it won't start, try unplugging the ICP sensor and see if it starts with it unplugged. It also can't hurt to make sure the fuel is flowing to the bowl . . .

 

Good call Pikachu. Here's a photo that might help you locate the items in question, specifically the ICP sensor on the drivers side head in front of the lifting hook.

 

So I went out today and checked the HPOP level. Looked to be about an inch down. Air temp was about 42.

Cranked over and started first hit today and no smoke. I will keep updating.

 

Ha! Figures... So we really couldn't eliminate that as a possible cause. I would keep checking it before your first start. PITA, I know...