Rough idle - little power

[BigRedWeather]

My idle has been very rough for a week. Three times the check engine light has come on. At 1000 + RPM it runs smoothly, thought has alot less power than it used to.

1st time the engine ran rougher and rougher and within 30 seconds it had lost all power, stopped and would not start. I had it towed home and the next day it started and drove 300 miles at 70MPH, with less power, but it ran.

2nd time after check engine came on it ran for another 10 minutes lost so much power that I almost didn't make it to my destination. I parked it, got back in in 2 hours and it went 70 up the interstate, still with less power.

3rd time I got to an autoparts store and they could not pull any code on it (the diagnostic tool was not great) he suggested I get I live diagnostic.

I have another Throttle Position Sensor on the way, but I don't think that is the problem because it isn't acting like it did when the PPS went out before. The Tach increases when I start it, and before the engine is running so I don't think it is the CPS. Also, the truck always starts in 1 second or less.

Might be the injectors but they only have 20k on them. If it were the injectors, I wouldn't think there would be such a wide range in power output, from barley climbing a gentle slope to running 70 -80 on the interstate.

Any other ideas?


BigRedWeather

 

[OLDBULL8]

When's the last time the fuel filter was changed? Auto parts stores can't pull codes on these engines, takes an AE like I have or compatible. Ford dealers usually get $100 for diagnostics. Look to see if the IPR or IPC is leaking oil.

 

[Double-S-Diesel]

check for a melted valve cover gasket, or harness

 

[Mutley]

Ain't that the classic symptoms of a closed EBPV? When that rascal remains shut things don't work too well.

 

[BigRedWeather]

I'll try to reply to three posts - thanks for responding.

The first thing I did when I got these symptoms was to change the fuel filter and the symptoms continued.

"check for a melted valve cover gasket, or harness" - don't see anything melted.

"Ain't that the classic symptoms of a closed EBPV? When that rascal remains shut things don't work too well." I'm pretty sure I found the EBPV between the turbo and the down pipe. The valve is stiff but I can open it by had maybe 20 degrees, and then it springs back. If I could approach it from a better angle, I think I could rotate it further. I appreciate the input, but I don't think this could be my issue because I can drive for 120 miles before I start loosing power. Seems if this were stuck closed I would notice it after five miles.

"Look to see if the IPR or IPC is leaking oil." First I have to locate these parts. I found some good suspects, but not in the location where they are supposed to be. Please look at my attached pictured and see if you can pick them out. I didn't see any oil leaks on these parts.

There are pictures of ICP1 ICP2 ICP3 - three pictures of this valve from 3 angles for a better view. In the pictures I labeled some of them IPC.

Your response is appreciated.


BigRedWeather

 

[BigRedWeather]

My pictures

 

[BigRedWeather]

My pictures, take 2. I've done this before with no problem.

 

[BigRedWeather]

There is diesel fuel in the engine valley, but I didn't see any oil.


BigRedWeather

 

[OLDBULL8]

There is diesel fuel in the engine valley, but I didn't see any oil.BigRedWeather

Check the filter drain valve, o'rings will leak there. Takes a #20 Torx for the screws.

 

[zpd307]

the icp is located in your first pic, you labeled it 1cp-1. pull that connector off and look to see if the connector is filled with oil or if the area around the threads is oily. your ipr in connected to the hpop, but from underneath, its a pits to get to. you should see the connector under the hpop, to the passenger side of the fuel filter housing. those o rings are known to rip and leak. my ipr just went out, in utah on an elk hunt of all places!!!! my symptom was a no start on a cold motor. i was told that is not common, but the code staored was for injection control pressure too high or low, and unplugging the icp sensor still did not allow it to start...

 

[Double-S-Diesel]

pict 1 the icp is on the right, the thing on the left is the exhaust back pressure sensor
pict 2 is the exhaust back pressure sensor
pict 3 the same
pict 4 that is tne fuel filter warning sensor

the ipr is in puct 1 about 3" ( full size pict)from the icp to the left right behind-below the flex line with the elbow


heres a link to the 7.3 bible
http://www.forddoctorsdts.com/articles/article-06-08.php

 

[BigRedWeather]

Injection Pressure Regulator Located

See the attached picture.

 

[BigRigTech]

Another culprit could be air intrusion if you found diesel in the valley. Is the fuel leaking from the lift pump? Is the fuel black? Find a shop with a Snap on solus scanner that can do some diesel tests to see if you can isolate the bad cylinder(s)....It will be worth the money and save you time. Even if the EBPV is closed they will usually run smooth at idle. My guess is either the UVCH's are bad or a bad IDM - the IDM's will usually play games until they give out completely.

 

[BigRedWeather]

Pulled codes

Thanks, BigRidTech. I will check into those.

I got a shop to pull the current codes off my truck and got a fist full of them (I had him clear all the codes):

PO122 TP Sensor Circuit low
PO123 TP Sensor Circuit high
COMMENT: I changed the TPS the day before I pulled the codes, so this should be solved now.

PO221 Throttle switch B circuit intermittent
COMMENT: I am going to check my transmission fluid level, though I think it is fine.

PO344 Camshaft position sensor circuit intermittent
COMMENT: Just before start by tack went above 0, so I don't have the classic CPS gone bad symptoms, but I thought a new one was indicated. I replaced the CPS and my truck noticeably improved in power and smoothness of running, thought it is still at about 70% of it previous power.

PO1211 Injector Control pressure higher or lower than desired.
PO1212 Injector Control pressure cranking not detected.
COMMENT: I have a diagnostic tool coming so I can pull my own codes. I will do so. Now that I have a new CPS and TPS I will address what codes remain.

As I am learning the science of addressing codes, and know very little of the art, comments are welcome.



Thanks,


BigRedWeather

 

[dyoung14]

Gotta love electronic diesels

I been trying to kill a miss in my step dads 94 for awhile now