2005 F250, 6.0, RWD, Crew Cab, 94K Miles

A few weeks ago, I started having unresponsive throttle here and there, you would press down on the peddle and nothing, no increase in RPMs and don't go anywhere. After 10 to 20 seconds, it would finally take off. Took it to my local shop, they changed the ERG, cleaned it all up, still happening, changed the high flow sensor, still happening, removed the catalytic converter, put in a test pipe and tuner on tow mode, still happening. Finally changed the fuel filters (not sure why this wasn't step 1), they hadn't been changed in about 25K miles. Ran like a champ for 4 days, then once again starting having the same issue.

As well, when sitting at a red light or parked, the idle is set at 750, but it will fluctuate anywhere from 700 to 850, just up and down, up and down, and sometimes drop down to 600 and/or die completely.

I to the engine up to temp, pulled the (new) top filter, removed the fuel, filled with sea foam, put the filter back in, put a can and half of sea foam in the tank with a little over 1/4 tank of fuel. Ran it for about 5 minutes then let it sit for about 30 min. Took it out, ran like a champ, took it out again this morning, put about 40 miles on it, ran great, but when I got back home, the RPMs are still fluctuating.

It seems to happen more after running for some period of time, when its cold or even up to temp but first thing in the morning, it runs great. However as I put miles on it, it seems to get worse, so the more miles I put on in a day, the worse it gets.

I'm not sure what else I can do, any ideas?

 

Do you have a way to scan readings? If not i would start there. See where everything is at. Have you done a blue screen update? Definitely sounds like it could be a fuel issue. A pressure test on your fuel system would be a good start. You could rent a pressure gauge from an auto store or buy a setup. They are a little pricey, but worth the money. Bad fuel pressure can cause a lot of damage to your system and be Real pricey.

 

It's a Blue spring upgrade. Damn auto spell. Sorry

 

+1 on what was said above ....... and don't go 25k miles again without changing fuel filters! 15k MAX!

The surging very well could be related to the ICP sensor. You might try disconnecting it and see how it runs.

 

No I havent, but been looking at doing it. Headed out of town, I'll get it ordered and do it as soon as I get back. Thanks.

 

My 2005 F350 was doing the same thing last week. I pulled up to a red light on my way to work and the rpms started to surge between 650 and 900 and when I went to push the throttle there was no response. After a couple attempts of turning the truck off and back on with no change I unplugged the icp and it cranked right up and ran like a champ. I replaced the icp later that day and the trucks been running great. I put about 300 miles in it this weekend with no problems.

 

Well the mechanic said he replaced the ICP sensor and the pressure control module. Said its running better and idles smooth. The bad news is he says he found 2 small metal shavings in the screen when replacing the pressure control module, which he says is an indication of the high pressure fuel pump going out. If it goes, he says thats a 7K dollar fix, his recommendation is to clean the truck up and bail on it.

So just curious, is the cost to replace the high pressure fuel pump really 7K?

Second, they have been in and out of my fuel system for several weeks now, even broke a socket along the way, whats the odds that the metal shavings is from something other that the fuel pump?

 

It really is a high pressure oil pump (not a high pressure fuel pump), but since oil actuates the injectors some people mistakenly call it a fuel pump. While metal certainly can be an indication of an HPOP issue, a failure on a 2005 and up HPOP is not real common. I wouldn't do anything w/ the HPOP based on that .... especially for two small pieces.

Also, $7k is OUTRAGEOUS!

I don't know what "bail on it" means, but IMO I wouldn't be thinking of selling it based on his recommendation!

He probably tore you a new one on just the ICP and IPR (not to mention the EGR valve and the testing on the exhaust, and I don't know what a high flow sensor is).

 

He's calling the IPR a pressure control module so i assume he means the Map sensor. Just a guess. And i agree wih Bismic not to take this persons advise.

 

Does the IPR have a screen where he would see metal shavings from the HPOP?

 

yes, that is why we posted what we did.

Ford has even documented a position NOT to change the HPOP for a few small pieces of metal. Who knows where they may have come from.

 

Thanks very much.

 

Well after replacing the IPC unit/sensor, it seems to idle and run great. The only issue I've run into is long starts, sometimes it will take 25 seconds of turning over before it will kick off. I talked to the mechanic and he said that sometimes the fuel will leak back to the tank and take awhile to build pressure. However I was in a fast food drive through, turned the engine off so I could hear, and low and behold, no start. 4 cranks, nothing, finally on the 5th try, I let it go, about 30 to 40 seconds and it kicked off.

I'm going to watch over the next few days to be sure, but if my memory serves correctly, I don't think the oil pressure gauge was moving until it started. Is this normal or should the oil pressure gauge be building pressure before it starts?

 

That is fairly consistent with a leak, a bad IPR (which even the new one might have another piece of metal in it), or a bad HPOP.

Even so, you should post cranking data for us to evaluate:
cam/crank sync
FICM sync
ICP pressure
ICP volts
IPR % duty cycle
cranking rpms
FICM MPower
FICM LPower
FICM VPower
Fuel Pulse width

If it is in the high pressure oil system, an air test should pinpoint the specific issue.

I wouldn't take it back to the same person. An HPOP should only cost a few thousand. A leak in the standpipes, dummy plugs, or an STC fitting should be much less.

Oh - before doing anything - verify for us what kind of oil filter cap you have - is it about 1" tall from the base of the housing to the bottom of the top hex plug? Or is it taller?

Also - IMO the fuel leaking back is a bad diagnosis! If you had a fuel pressure sensor, you could prove it. Now - once again he may be talking about the high pressure oil bleeding off, but it sounds like he thinks there is a high pressure fuel pump - and there ABSOLUTELY isn't one!!!

btw - turning the key on without cranking will develop the needed fuel pressure. The OEM fuel filter (secondary one) has a self venting feature that will quickly let the air out.

 

Yeah I plan on finding a service shop that deals with diesels, and have them look at it. As for the cranking data, I'm not sure how to get all of that.