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 T444e. Rough idiol while stopped in gear.
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Mark23290
Senior Member

United States
69 Posts

Posted - 03/02/2013 :  08:22:46 AM  Show Profile  Reply with Quote
2000 International, runs fine at idiol and in neautral and when driving it.
Runs rough and loud while stopped in gear foot on the brake.

Seems to run fine for a while when it's cold then it starts to act up.

No computer to pull codes, no dash lights on and no smoke from the tailpipe.

Can you guys lead me where to start looking?


I've heard Icp sensor? Where would it be located?

Thanks

baptistbusman1
Senior Member

USA
76 Posts

Posted - 03/02/2013 :  09:59:29 AM  Show Profile  Reply with Quote
are all the cylinders getting warm when it's first started?

I was formally Baptistbusman. However, I lost my password, and had not updated my email address.

Here is a link to my old posts. http://www.schoolbusfleet.com/forum/search.asp?mode=DoIt&MEMBER_ID=1846
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Derbybug
Active Member

USA
49 Posts

Posted - 03/04/2013 :  04:47:50 AM  Show Profile  Reply with Quote
Have you done a stall test to check the torque converter? Sounds like the converter may be starting to lock up
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Mark23290
Senior Member

United States
69 Posts

Posted - 03/04/2013 :  08:24:43 AM  Show Profile  Reply with Quote
I'm sorry I'm a contractor and owner, mechanically inclined to an extent but do not have the computer stuff to plug in to it. Can I ask Stall Test? (Derbybug reply). Also I'm not sure if all cylinders are getting warm or not. How can I tell?

Only thing I can tell is once it gets to 190 degrees and I put the foot on the brake it chugs a bit but sounds like it is louder and running rough. If I just take the foot off the brake and not accelerate it will idol up a pinch and smooth out then I give it some accelerator and it runs fine. If I just put the foot on the accelerator it will kinda hesistate or feel like no power then it will take off within less then a second and run fine.

I tried unplugging the ICP sensor and that did not change anything. I cleaned the fuel screen as well the other night. The air filter is a little dirty but I would not think that would have anything to do with this, would it?

The garages around here kill you and 90% the time never are truthful with you.. So I'm trying to save a dollar and hope I can figure it out. Seems like it could be something as a loose or broken wire or bad sensor somewhere. I appreciate everyones help and understanding.

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Derbybug
Active Member

USA
49 Posts

Posted - 03/06/2013 :  09:50:22 AM  Show Profile  Reply with Quote
Mark, Sorry for the delay in getting back to you. We had a snowstorm here and I got sidetracked by other duties. To perform a stall test, chock all four wheels, and set the parking brake. Watch the tachometer. Place your foot firmly on the brake pedal and place the transmission in drive. While holding the brake pedal press and hold the throttle pedal to the floor for 2 or 3 seconds. This test places stress on the transmission and the torque converter. Never exceed full throttle for more than 5 seconds. Compare the reading (stall speed) on the tachometer to the manufacturers specifications. On an Allison AT545 it should be around 1100-1200rpm. If the tachometer is below this the torque converters stator one way clutch is spinning freely or there is a restriction in the exhaust system. If the reading is above 1100-1200 the transmissions clutches and bands are slipping.

You may want to check the EBP (exhaust back pressure)sensor and tube for restrictions as well. They commonly get clogged with soot and will reduce power when they are clogged. This keeps the wastegate closed and restricting exhaust. Let us know what you find out or have more questions. Good luck

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Derbybug
Active Member

USA
49 Posts

Posted - 03/06/2013 :  09:56:45 AM  Show Profile  Reply with Quote
One other thing..... you can check to see if all 8 cylinders are firing by starting the motor and use a laser temp gun to measure the exhaust manifolds at each cylinder to determine of all 8 cylinders are working properly. The readings should be close to each other for each cylinder but the back 2 on each side will run a little hotter than the front 2 beacuse all 4 on that side run thru the same manifold. It doesn't sound like you have an injector problem since a faulty injector will most likely malfunction when the engine is first started up especially in colder weather.
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Mark23290
Senior Member

United States
69 Posts

Posted - 03/07/2013 :  05:01:01 AM  Show Profile  Reply with Quote
The stall test checked out ok. Unplugged Icp sensor and no change.

Question, my check trans filter light has always been on for years, but I moved the black tape covering it and the check trans light is on. Could there be a sensor on the tranny?

It had a new tranny a couple months ago and then in for a leaking tranny cooler line.

About to just take it over to the dealer.

Runs fine while moving and driving, just short lack of power at take off and rough sounding and feeling while Idiling in gear foot on the brake.
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Derbybug
Active Member

USA
49 Posts

Posted - 03/07/2013 :  05:37:53 AM  Show Profile  Reply with Quote
Did you check your EBP sensor & tube?
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Mark23290
Senior Member

United States
69 Posts

Posted - 03/07/2013 :  08:45:38 AM  Show Profile  Reply with Quote
No, I will check on that this weekend. No garage so have to work outside and we got hit with snow yesterday. School cancelled but still had to work the othe job between bus.

Thanks for all the suggestions.
Is there a simple way to check the Ebp? Like unplug it like the icp.
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Derbybug
Active Member

USA
49 Posts

Posted - 03/07/2013 :  09:47:02 AM  Show Profile  Reply with Quote
The EBP tube runs from the right exhaust manifold to the sensor, located next to the high pressure oil reservoir on top front of the engine. Unplug the sensor & remove it. Inspect the tube for clogging & take an air gun with a rubber tip on it. Stick the air gun into the tube & blow air into it. If it blows back at you, the tube is clogged. Chances are your sensor is clogged too then. If it is clear, it will kind of whistle into the manifold. If you hear it blowing air but not into the manifold, it most likely is rusted thru & has a hols in it & needs replacement. If the tube is clogged replace it. Some guys try to clean them out, but I just replace them. The tubes usually aren't that hard to replace but it is kind of tricky to get the new one aligned properly. Soak the manifold connection with WD40 and work it back and forth til it comes off. The tube and sensor are not that expensive and will cure rough idle and low power complaints. Part numbers are listed for ease in ordering.

EBP Tube #1831224C2
EBP Sensor #1850353C1

Both are readily available. If you dont have an INTL dealer close by, try a Ford dealer. Its the same parts for any 7.3L PowerStroke.

Good luck & let me know how it comes out.

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Mark23290
Senior Member

United States
69 Posts

Posted - 03/07/2013 :  12:49:41 PM  Show Profile  Reply with Quote
Update:

With the bus is drive or reverse, foot on the brake I can press the accelerator to the floor and even hold it there, and it doesn't move nor rev up. Like the accelerator is disconnected. If an when I let foot of brake the bus idiles and starts to move then it accelerates just fine.

Now the only time it does any of this is when it's warm. Cold it runs fine.

And when you slip it into neautral it is running about 1000 rpm on the tach the goes back down.

I recently had tranny work and a complete rebuild. Is there sensors or vacuum lines on tranny? Does this info help narrow it down more?

Thanks again for the insight and help.
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Derbybug
Active Member

USA
49 Posts

Posted - 03/08/2013 :  04:12:07 AM  Show Profile  Reply with Quote
There are a couple fittings on the trannny. Vacuum modulator on the left side, Reverse sensor on the right, speed sensor on top of the tail, oil temp sensor on some of them. I dont think any of these malfunctioning would cause the symptoms you are having. Focus more on the engine and/or torque converter.
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Mark23290
Senior Member

United States
69 Posts

Posted - 03/08/2013 :  7:13:08 PM  Show Profile  Reply with Quote
Well today while driving I went to back up and the tranny squealed and like slipped not acted like the brakes where on and forcing it..

Fluid is in normal range according to dipstick, so maybe your right about a torque converter issue. Just don't understand how it make it idile rough only while in gear and foot on the brake.

If the tranny is dead it will be the second one in six months. Very frustrating!!

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Derbybug
Active Member

USA
49 Posts

Posted - 03/12/2013 :  04:13:03 AM  Show Profile  Reply with Quote
If the torque converter is locking up, it would act like a direct drive to the rear end. There would not be any clutch action between the engine and the rear end. Think of it like this, if you drive a manual trans & are stopped at a stop sign. Then you start to let the clutch out while holding the vehicle stationary with the brake. The engine will start to idle rough and start to chug and try to die. It is the same thing when the torque converter starts going bad.
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