Missing at cruising speed

[Schnot]

I pull trailers with a 2000 F550 and it runs great usually. The other day I was on the way back from a trip pulling our wedge trailer and it started missing. Mostly when you try to accelerate but also at idle and a smooth RPM but it just not as noticable. Then its like someone flipped a switch and the check engine light came on and the truck started running good again. I tried changing the Fuel filter and running lots of anti-gel and injector cleaner through it but that didnt seem to help much.

I'm guessing that my problem is probably some kind of sensor that is dirty or faulty but im not sure as to what. I can pull the codes tomorrow and post them on here if that will help.

It has a Superchips programmer set on Tow Safe mode, 5 inch exhaust and a k&N cone.

Thanks!

[KnockingDiesel]

I ran into a similar problem, it was a harness under valve cover. I was going to CO. it was rough idle and low RPMs, but good above 2000rpm. the engine needs the computer to run at low rpm but mechanically over comes it at 2000 rpm and above. hope this gives you an idea.

[Schnot]

I know that it isnt the harness. At least its very unlikely as I just replaced them with new ones and they only have about a thousand miles on them or so. And this is a 550 with 4.88 rears so i hit 2k RPMs at about 55 mph and I run it at about 70 usually.

Codes that I pulled were P0472, P1209, P0603, P1211, P1212, P0732, P0541, P0237, P0541

And that is pulling the codes once then clearing them driving another hour or two and pulling them again.

It has to be something so simple!! Grrr its killing me!!

[KnockingDiesel]

My truck did that I don't know the codes but it every time the engine light came on a code came up. Was the harness dealer installed? Most dealers like not doing it right.

[chvyrkr]

Originally Posted by KnockingDiesel

I ran into a similar problem, it was a harness under valve cover. I was going to CO. it was rough idle and low RPMs, but good above 2000rpm. the engine needs the computer to run at low rpm but mechanically over comes it at 2000 rpm and above. hope this gives you an idea.

Whoa, what?

The engine absolutely needs the computer through the entire RPM range brother. The computer is actually one of our limiting factors in gaining higher RPM's in performance applications.

Who told you otherwise?

Originally Posted by Schnot

I know that it isnt the harness. At least its very unlikely as I just replaced them with new ones and they only have about a thousand miles on them or so. And this is a 550 with 4.88 rears so i hit 2k RPMs at about 55 mph and I run it at about 70 usually.

Codes that I pulled were P0472, P1209, P0603, P1211, P1212, P0732, P0541, P0237, P0541

And that is pulling the codes once then clearing them driving another hour or two and pulling them again.

It has to be something so simple!! Grrr its killing me!!

Codes are:

P0237 - Turbo Boost Sensor A Circuit Low Input / MAP sensor code, might come into play here.

P0472 - Exhaust Back Pressure Sensor Circuit Low Input / I'd probably ignore this, it won't cause the issue you're having.

P0541 - Manifold Intake Air Heater / Ignore, nothing to do with this issue.

P0603 - Internal Control Module KAM Error / Ignore this code anytime you see it. It's caused by resetting the PCM with a hand held tuner more often than not. Not an issue in any case.

P0732 - Gear Two Ratio Error / Are you having trans issues?

P01209 - Injection Control System Pressure Peak Fault / ICP was to high for to long, might come into play.

P01211 - ICP Not Controllable - Pressure Abow/Below Desired / Self explanatory, it's having issues controlling ICP.

P01212 - ICP Voltage Not at Expected Level / IPR code, think we found the culprit.







First, just because you replaced the UVCH's doesn't mean they aren't the problem. More often than not the problem isn't the harness, it's the connector outside the valve cover. It's poorly designed and will loosen up on you. Ford has a wedge that fits in the connection and holds the safety to keep a tight connection. If they're not already installed, you can pick 'em up at a dealer. Or, do a search for the "50 cent mod" and you'll be in business for the price of two quarters.

Now, I think your problem is almost definitely IPR related. The IPR is on the HPOP. HPOP is under the fuel bowl. The IPR threads into the pump, at the bottom of the pump, on the drivers side. There is a two prong/two wire connector going to the brass solenoid on it. The brass solenoid has a stamped brass nut holding it to the IPR. Make sure this nut is tight, and make sure the two prong connection is clean and undamaged. I think that your brass nut has backed off the solenoid and is messing with the voltage.

As for the MAP sensor. During acceleration, the PCM will look at the MAP for a fuel to boost reference. If it's not seeing boost through the MAP, the PCM won't command more fuel to match acceleration and throttle position. This could cause the hesitation and stumble you're reporting. So, check the wiring harness and connector to the MAP sensor as well. I don't think they're very expensive, so if there's nothing visually wrong with your IPR, replace the MAP sensor.

[dhanna6powerstroke]

Originally Posted by KnockingDiesel

I ran into a similar problem, it was a harness under valve cover. I was going to CO. it was rough idle and low RPMs, but good above 2000rpm. the engine needs the computer to run at low rpm but mechanically over comes it at 2000 rpm and above. hope this gives you an idea.

This is incorrect info. Computer needed at all times.

Originally Posted by KnockingDiesel

My truck did that I don't know the codes but it every time the engine light came on a code came up. Was the harness dealer installed? Most dealers like not doing it right.

Not sure why you would say that unless you personally have had a bad experience. You can't generalize all dealerships based on that.

[KnockingDiesel]

Sorry guys, let me explain a little better, I know the truck needs the computer at all times (air/fuel ratio, egts, boost, waste gate, etc.) The harness that went out on my truck was the right side, I cant remember but I think there may have been a sensor but any way from idle to about 1900rpm it ran on only 4 or 6 cyls (I mean bad) after it got past 2000rpm the engine ran fine, I was on my way to CO. from N.M. I pulled in to a ford garage and the tech told me that there something that the engine has to control it while no load is present on the engine but once it gets going it relies on a different area of sensors and he went on and on, I didn't pay much attention to him, when I got home (yes I drove it home the way it was 80mph seem to keep it running normal) I took it to my local dealer my guy was but one of the other techs said a similar explanation, I told him just fix it and its been fine since (thank God for Ford ESP).

I am not a diesel mechanic nor claim to be, I have basic mechanic skills when it come to diesels (fuel filter, oil changes, etc. ) I was just passing the info given to me by a Ford Dealer. Sorry to p.o. anyone.

As for the dealers not doing their jobs I agree it varies greatly from dealer to dealer and not all dealers are the same BUT I have had bad experience with dealers from AZ, TX, CA, UT, CO and NM. The other states were all minor issues (oil change and did not put my oil fill cap on, loose oil filter, loose drain plug, loose fuel filter canister and stuff like that), but, there is more than one local ford dealer out here in NM where I live and of the three big ford dealers one is great, one stole my radio and the other nearly totaled my truck while in service(not my dually a F150 we went to court and they wound up having to replace bumbers, a fender both driver doors, a wheel, a tire and a new driver quarter panel).

Sorry to have misled a fellow member.

[chvyrkr]

The same sensors send info to the PCM through the entire RPM range, and the PCM sends it's commands through the same wiring harness through the entire RPM range.

Find a new tech.

[KnockingDiesel]

He is not my tech he works the the late shift (after 4 pm.) the tech that I always use was on vacation they had to keep the truck for a week for what ever reason, like I said, I have no knowledge about diesels beyond routine maintenance.

[Schnot]

Just a quick update: It was the IPR. The nut was loose but the magnet wasnt off and I tightened it and still had the same problem. So I just rebuilt the IPR and its running perfect ever since.

A little Carb cleaner and diesel fuel is all it took.

Thanks!