Hey guys. I need help. I've searched and searched through threads but can't come up with anything quite like the issue I'm having. I do not have a no start condition, the GP's are working great. When it is even cool outside (below 50 Deg) my truck will not stay running until the oil builds up heat. If I have it plugged in and keep the oil warm, it will start, run, take off just fine. It acts like somebody is choking the fuel off. I know it's HPOP related, just not sure where to start. I put a new engine in about a year 1/2 ago, you may remember that. Truck has 148K miles, engine has about 2K on it. Original HPOP and all the sensors. Fresh oil, etc. Once start and it goes into this condition, it will just stall out. Starting it takes a bunch of cranking and holding the throttle to the floor. It will eventually start, cough/sputter and then die. Once I can get a bit of heat in the oil, it will all of a sudden run perfect. Pulling trailers up hill etc. with full power. This only happens until I can get heat in the engine. Help please!! I have a couple long trips in the next few weeks up in the hills where it will be cold over night. 99 7.3.

 

Low engine oil level could cause that but u prob already checked it.

 

I've watched the relationship between ICP, IPR, and EOT... things are going on in there. Your ICP is suspect - try unplugging it the next time this happens.

 

I am somewhat suspecting ICP also but wanted to get some additional thoughts. Will the truck start with the ICP unplugged?

 

Yes... possibly better than in a while.

 

Thank you. I'll reply when I get results of my findings.

 

Typical of a crack in the oil pickup line in the pan.

Oils warm, easy to suck up, fills HPOP normally.
Oils cold, thick, hard to suck up with crack/hole in pickup.

 

New ICP (new Ford part) Same issue. I am getting P0470 and P0478 codes for the exhaust pressure sensor. I don't think that is my problem. Could the IPR be causing my issue?

 

What happened when you unplugged the old ICP? Did the problem clear up?

 

No, starting was just as difficult. What I did last night is go ahead and clear all codes. There were stored 1210 and 1211 codes, so I do believe the ICP did have some issue. It also was a bit oily, further indication of a problem. I then changed the oil again to make sure all is well there. I left the batteries unplugged during that. I also loaded the stock tune. Today it seems to be running full speed, but I did have it plugged in last night to have warm oil this morning as I needed it not to give me any issues. After towing about 12,000 lbs today for 20ish miles, I loaded the tow tune back in at it seems to be pretty happy. I'll have to test the cold start later to see if the issue remains. When it's warm, it is very happy and runs at full power with no unusual effects that I see. Driving me nuts! Only codes right now are the 470 and 478, so do need to get that sensor fixed, but probably not any of my issue.

 

The book:

DTC P0478 indicates an excessive back pressure condition existed during normal driving.
 Possible causes:

• stuck EBP butterfly valve
• restricted exhaust
• plugged EBP sensor line
• misadjusted EPR linkage
• F-Series wastegate turbo may be overboosting

 

When I put the new engine in last year, the EBP sensor line was plugged and also busted at one place. I cleared the manifold plug and replaced the line, but not the sensor. I probably need to replace that. Other issues for that one are clear. Thanks for the info!

 

To help diagnose if it is a cracked pickup tube you could try running T6 5W40 synthetic oil. If it runs and starts normally with the thinner oil then you have a really good indication of what h2guy was talking about. All this is assuming you are running reg 15/40 dino oil currently.

 

you could also pull the plug out of the HPOP when you are having his issue...if it is empty that would also indicate a LPOP/Pickup tube problem.

 

Further proof of a cracked pickup will be found by parking the truck nose down as much as possible and it will then "normally" crank and fire as it should.

That, or plug it in for a few hours.