I have done a bunch of searching but cannot find a thread that has a problem exactly like mine.

99 7.3 misses when starting it cold (first start of the day even when outside temps were around 20 deg C ). It has a noticeable miss and lots of white smoke. After warming up it runs perfect. I changed the GPR and tested all glow plugs, 3 bad and one weak one all replaced. Now that it is cold out it still misses when first started, even if left plugged in. It will start and run for approx 3 seconds perfectly smooth then it starts to miss and idle speed slows down. on one occasion I went to start it after sitting 10 plus hours plugged in and it started then missed and slowly died. Would not re start, It was firing and smoking but not enough to get going again. Went back the next day and it started and ran fine for a few weeks. Did the same thing to me yesterday, started and then petered out and died and this time it will not re start after 2 days of trying on a couple occasions. I changed out the CPS with no luck.

Thanks in advance for any ideas!

 

So, now you are certain that the GP's are working?

Pull the plug on your ICP snesor and see if there is oil in it. DS VC toward the front.

Whether there is oil in the connector or not, leave it unplugged and attempt to start the truck. This will cause the CEL to illuminate, it will not damage anything to continue to run the engine and drive the truck for a test to see if this is the problem. If it starts and runs better...

If not, check to see if the tin nut is on the back of the IPR?

If it is loose tighten it. If it is missing, you'll need to get a replacement.

Check your oil level. Fill it if it is low.

The above is a decent starting point.

 

Thanks for the help, had the truck back in the shop and they did the following:

-Test block heater - Good
-Test Glow plugs - Good
-Test battery circuit - fix lose ground on passenger side
-Check fuel pressure - 60 + psi, good flow
-Check fuel filter - good
-Clean fuel bowl, replace non working fuel bowl heater
-KOEO - No DTCs
-KOEO - no memory DTCs
-Injector buzz test - P1294 left bank high side
-Test left bank injectors - all good
-Test harness - good
-Replace IDM (used rebuilt)

Truck ran perfectly after this, started cold with no miss and no smoke. 2 days later (4 or so good starts) I left it plugged in and went to start, ran and then missed bad and died. Would not re-start, firing but not enough to catch.

-I replaced both sides UVCH

Managed to get it started after this but it was running rough and lots of smoke again.

-Unplugged ICP, no oil in the plug and no noticeable difference in it running

Smoke and rough idle clears up when warm and truck runs fine. I am now leaning towards the IDM failing again or possibly a bad IDM relay? (have not dug into the IPR yet.) Thinking IDM because of how good it ran when it was replaced....

TIA

 

So is heavy white smoke always present at cold start up? Have you tested the GPR when the key is first turned on and timed how long the relay stays energized?

 

Yes heavy white smoke on startup and very noticeable miss. I have not tested how long it stays on I can do that tomorrow. Another symptom I noticed today was after idling and warming up about 10 mins then driving approx 2 miles, truck was almost at full op temp. When slowing down on the highway then turning off it started to miss and smoke for a few seconds when trying to accelerate again. Overall seems to lack power.

 

White smoke at cold start is almost always a glow plug issue. Missing while slowing down at full operating temp is never a glow plug issue.

How many miles on your current engine oil? What weight and brand oil? Is the engine oil full?

The rebuilt IDM adds another degree of difficulty in diagnosing this since there are all different quality rebuilds. When the truck misses, does the CEL ever come on?

 

Less than 1000 km on the current oil, right up full operating level. Rotella 5w40 synthetic.

I have never seen a cel come on.

The biggest stumper for me is that the new idm made it run the best it has in the last year, no smoke no miss. Then the same symptoms came back only a couple days later.

 

Or the new IDM masked the symptoms for a few days. Speaking of which, do you have a chip or tuner on the truck? If so, remove it or program it back to stock. A chip can mask symptoms as well.

If your truck is missing and you're not getting a CEL, that limits the things to look at. Glow plug issues, fuel pressure issues, air intake issues, and worn injector issues won't typically trip the CEL.

When you test the GPR on time tomorrow, if it cuts off in less than a minute, lay a screwdriver across the 2 large posts on the GPR (will spark when you make the connection) and hold it there for 90 seconds and then start the truck to see if that makes a difference.

You might end up needing to pull the valve covers and watch the oil discharge from each injector when starting and running cold. Then watch to see if flow improves or some injectors come online as the engine warms up.

 

Good point on the chip, has a bullydog 6 position when I had no start I turned it back to stock with no difference. I didn't realize that changing out the idm could mask symptoms like that.
I may end up bringing it to the Ford dealership and let them scan it properly. I'm in -10 degree weather and my garage is too small. Taking the valve covers off again in the snow doesn't bring me happy thoughts.... Lol.
Thanks for all of your help, I'll try out the gpr and report back.

 

Remove the bullydog for diagnostic work. Just switching it back to stock isn't the same as actual stock. It's just a stock tune on the bullydog. (same goes for any chip)

 

Well a bit of an update on the truck. I watched the interior light and it dims noticeably for at least 45 + seconds when the truck is cold and the GPs turn on. IPR nut is on and tight. It has started for me for the last couple of weeks although it is still running rough and smoking out the neighborhood when its cold. I have noticed that it will run smooth for about 5 seconds at the very beginning on cold start then develops a very noticeable miss and the diesel fog starts. Have not been able to find anybody with that symptom.

 

This could be an IPR coil problem, but that would likely trip the SES. If you had an OBDII adapter and app on a portable device, or the adapter and FORScan on a laptop, we'd get this figured out right-quick. For less than the cost of a single computer hook-up at the dealership, you can have your own permanent means to hook up as often or as long as you like.

 

Just throwing this out there.... please don't chastise me. What about the EBP Sensor?

I know, it's a shot out of a cannon.

 

That's not so far out there. There are some mysteries with the nature of the EBP signal that nobody has resolved yet. One member had a lot of problems when his EBP sensor shorted and took the reference signal down with it. If there is a leak in the sensor tube, the sensor itself can get hot enough to melt (raising hand).

 

Considering what he has done to the truck I would have to "assume" that it's going to be something "random". In my opinion I would spend the $80 and put a new part in along with cleaning the tube. If I am not mistaken the EBP sensor communicates with the PCM for proper fueling.