Before I condemn the HPOP, I thought I would let the forum have a shot at my problem. For a long time I have been experiencing a "surge" mainly noticeable at part throttle. I.e., running 45 mph and it feels like the engine stalls or surges. It's like it can't make up its mind to add fuel and then it does and it doesn't.... Annoying but it does not stop running completely.

Now it is extremely hard starting, especially when cold. If it does run, usually after a jump or battery charge, if I do not let it warm up thoroughly, it runs very rough and sometimes stalls and will not restart. It feels like a gas engine that gets so flooded, that you have to pull the spark plugs and dry it out. That's just my way of describing it, I know how a diesel works.

So far I have seen 1211, 1210 codes intermittently. Changed the ICP, topped off the HPO reservoir alittle. Still was very hard to get running w/ 50 degree outside temps. Once it finally caught, after 3 cycles of the glow plugs, it ran rough at first then gradually smoothed out and was running with tons of power on WOT, but still "surging" while obeying the speed limits.

It has new glow plug controller. covers have been off (quarters cut and inserted)and there were no loose bolts or connectors. Should have done the GPC first. While the top was apart, a new cartridge and improved wheel was installed in the turbo.

Excursion has 298,500 miles with no work, other than mentioned above plus large exhaust and K&N filter. It has an Edge plug-in silver box tuneup set on emission illegal and smokes quite a bit on WOT. I tried setting it back to the stock tuneup. It did not help and it sure was slow!!

Cam position sensor replacement made no difference, either.

One other tell tale sign. It improves about 50 miles after an oil change, but still is there, just not as bad.

As an aside, how many of the sensors/ switches can be unplugged or jumpered out and still have the engine run?? How many would actually improve fuel economy and/ or performance??

I am ready to tackle the HPOP, or any service that might help this thing run like it should. Help

 

I have a similar problem. Changed the HPOP and the injectors. Still have problem.

I was told it was all in the tune.

Do you have a tune on yours?

 

Just have the plug-in Edge programmer which changed the tune up in the truck's computer.

Does changing the oil have any effect? It seems like fresh oil helps lessen the problem. That's why I was suspicious of something in the HPOP circuit??

 

Have you dropped the tank and cleaned the pickup screens in the tank? Its quite possible there getting plugged starving the motor for fuel. I did the hutch mod on my excursion and it made a huge difference. Do you have a way to check the fuel pressure? Another good fuel mod is the FRX

http://www.guzzle7pt3.com/hutch.php

http://www.strictlydiesel.com/p-2662...-pump-kit.aspx

https://www.ford-trucks.com/forums/1...hutch-mod.html

http://www.riffraffdiesel.com/mm5/me...Category_Code=

 

300 thousand miles? You are a candidate for injectors. I see you can pull codes, but there is no mention of being able to take readings on sensors. Save yourself the headache of throwing parts at it, and spend money on diagnostics before your next move. You can get AutoEnginuity software or at least an OBDII multigauge and use the last links in my signature to troubleshoot it (a copy of the Powertrain Control / Engine Diagnostics manual would complete the diagnostic device). OR - have a shop really determine what it is. You can have a lot of misfires when pulling the trigger on parts just because a code said so. Bad O_rings will cause low Injector Control Pressure. So you replace the O-rings and you find the injectors are doing something different, but it is still hard to start. At 300K miles, it really needs some going through. Sensors fail or get incorrect, dielectric grease in the connectors dries out, injector wiring harnesses weaken and come unplugged under the valve cover, the Injector Pressure Regulator can stick and drop the ICP, etc....

If you choose the AE w/Ford bundle route [LINK], or something similar to a Scangauge, we can help you figure out exactly what's going on in there, and you can use this powerful tool for the next 300K miles.

There is one sensor you can try unplugging, you can pull the ICP... just to see of it starts and idles better. The T500 link in my signature will show you where it's at.

 

Thanks. I need to get a better decoder than the one included in the silver Edge box.

 

I just looked the the AE page for the scan tool examples of the 7.3 screens. I had no idea there was so much going on in that little brain! Now I need to come up with the dough to buy it or find a shop near me that has it. Swamp's is about 380 miles away. I am tempted to make an appointment and get the whole thing sorted and repaired correctly.

Its either that or put in the Cummins I have my eye on.

Thanks again.

BTW, it was about 30 this morning, the truck started up and ran pretty well with a few minutes of warm up time. Felt some "surging" at about 45, after the engine warmed up (about 3 miles) from the house. It was intermittent, as usual. And actually was barely noticeable several miles later. Fresh oil made a difference.