(First, this is a great site, with lots of valuable info and very helpful people)

I have a 2004 F250. Bought last January, with 214,xxx miles. So far, replaced an injector (stranded on the road), radiator (stranded on the road), alternator (stranded on the road), aux fan (No A/C at stoplights, but not stranded on the road - just hot, I'm in TX)), Brake calipers. I so want to keep the truck, but its turning into a money pit. Recent oil change with Archoil added.

The latest issue is rough running - cold, hot, doesn't matter. Started abt 2 weeks ago. Driving home, between 55-65 I get a violent shaking from the engine. Let off the accelerator, and all quiets down. Press the accel, and it bucks - a lot until I reach 70 mph, or 2500 rpm. If I hit tow mode, and the rpms stay up, it usually runs OK.

Reading a lot of posts here, I got a ScanGuage II. At first, I thought FICM. The reading on it is 47.5 to 48.5, so I've ruled that out. Then, thought another injector. There aren't any misfires logged. No codes are logged. RPM fluctuates a lot at idle. ICP seems OK. VGT seems OK (65-70 at LI, 50 at 1500 rpm/65-70 mph)

What I did notice tonight, is vlt fluctuates widely during running. Mostly stays at 13.5 to 13.8, but can go up, or down regardless of rpm. however, when I stop and turn the key off, it drops to 13.1, then continues down into the low 12's until the SGII turns off. Do I just have (a) bad battery(ies)? Is there some other xgauge I should be looking at to pinpoint the problem?

Suggestions for a dsl newbie......

 

Sounds Like another Inject

Hows Fuel pressure??? Changed fuel filters recent??

You really should install the Blue Fuel Pressure Spring


Are you doing all the wrenching??? you may be able to save some Money



Do an Injector Bubble Test


And welcome to FTE

 

Oh do you have all the Gauges specific to the 6.0L programmed into the SGII??

since you have the SGII might as well put it to work

Post these
ICP
ICPV
IPR%
FMP
Volt
Baro
Map
EBP

 

Thanks for the fast reply. I'll get the readings for the x gauges you have listed.

I'm not doing a lot of the wrenching myself. I used to "think" I'm more mechanically inclined than I actually am - so I've learned to stay away from stuff that I can break that cost a bunch of money to fix

Can you explain the "Blue Fuel Pressure Spring" and Injector Bubble Test? I'm unfamiliar with these.

 

The blue spring is a replacement regulator spring that boosts the
pressure back up to where it should be to keep injectors happy.
https://www.ford-trucks.com/forums/1...ue-spring.html

Read that link and it will give you all the info for doing the Blue Spring.

What were the ranges for the voltage when it was bouncing around?

Sean

 

While you are programming the SGII, charge the truck batteries and load test them individually. Then have the alternator tested. Voltages should not fluctuate very much when running. As Sean asked - what is the actual voltage variability when you state that it can go up or down regardless of rpm?? 13.5 to 13.8 variability is normal. Dropping down to the mid 12's is normal when shutting the engine off. Being in the high ten's when cranking is normal also.

Also, please tell us where the ICP sensor is on your truck. The ICP and IPR readings are of specific interest I would think.

 

The codes are....

ICP..... 638-640 (LI) 1180-1380 @ steady 65 mph
ICPV... .8 -9 (LI) 1.28 - 1.98 @ steady 65 mph
IPR%... 23 (LI)
FMP.... 48 (LI) 47.0 - 48.5 @ steady 65 mph
Volt.... 13.2 (LI) 12.9 - 14.1 @ steady 65 mph
Baro... 14.5 (LI)

Map and EBP... I cannot get either of these last 2 to display. dbl checked the entry, but nothing.



Thanks, all, for looking.

 

Depending on what year model your ENGINE is in your 2004 truck (2003 or 2004) it may or may not read EBP. If there is a sensor (ICP) in the front top of the passenger side valve cover it's an 04 engine. If the ICP sensor is under the turbo (very hard to see) it's an 03 engine. 03 engines use an inferred EBP value in the PCM strategy and will show nothing on the SGII. If you're not reading MAP values either double check the entry for your SGII (it's easy to get a value misplaced) or check the MAP sensor itself. There's also a hose attached between the sensor and the intake manifold. That hose and/or the attaching nipple in the intake can get clogged and might need poked out with something thin. Also, the SGII probably will not show any codes on your truck. You can get those read at an autoparts store for free.

 

My truck build date is 08/03, so I assume its an 03 engine.

When replacing the upper fuel filter last week, I noticed a small hose to the left of the filter was off some nipple. Is this the MAP hose you are refering to? I don't know if it was off prior to me messing around with the filter. The rough running was there before the filter change, and is still there. If the hose is clogged, would that pop it off?

 

The hose has a clamp on it so I don't think it would pop off, but it would sure make your truck run bad. Usually it's not the hose that clogs, it's the nipple in the intake manifold that gets clogged. The SGII not reading the MAP sensor is disconcerting. Sometimes you have to key off and let it go to sleep and then key back on. It's quirky like that.

Yes, your truck has an 03 engine. The cutoff date is 9/29/03. After that they had 04 engines, but the sure way to tell is the ICP sensor location. You won't get an EBP reading.