DDEC II will only run @ idle
 

DDEC II will only run @ idle

Started by bpo, September 05, 2008, 01:57:43 PM

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bpo

6v92 DDECII When you use fast idle 1000 rpm or more the stop engine & shut down engine lights come on. If you let it idle @ 600 rpm it will run all day with no warning lights on, if you manually hold rpms @ 1000 or more it will shut down.
It has good oil pressure and water temp is good.

Thanks,

Brian

Blacksheep

Brian do you know how to read the blinking check engine light to determine what code/s or faults that are allowing the engine to shut down?
Its very easy to do. Turn on the ddec test switch and your ignition key to the on position. Looking at the check engine light known from here on as CEL and your stop engine light known from here on as SEL. There may be 1 light and a pause then maybe 5 blinks which would mean 15. Once you have the code/s, I can relate my ddec diagnostics book to get you in the ballpark!
You can even call me on my cell.
863-559-9067. I have the book with me!
Ace

makemineatwostroke

Low fuel pressure could be the filters or the sensor

NJT 5573

You can unhook the sensor on the fuel filters and see if the problem goes away. You can unhook most all of the sensors on DDEC 2 and if you get the right one off it will run. Last time mine did this the oil looked good on the stick, but thats what it wanted. Low water, same deal.

DDEC 2 inputs are Timing, Throttle Position, Turbo Boost Pressure, Oil Temp, Oil Pressure, Coolant Level and Fuel Temp.

I would cycle the power switch the required times and see if the throttle position sensor resets.

Read the codes, and you will know what to look at.

"Ammo Warrior" Keepers Of The Peace, Creators Of Destruction.
Gold is the money of Kings, Silver is the money of Gentlemen, Barter is the money of Peasants, Debt is the money of Slaves.

$1M in $1000 bills = 8 inches high.
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$1T in $1000 bills = 142 miles high

NJT5047

I agree with Ace and NJT5573...but, before unhooking anything, do as Ace suggests...read the codes.   Whatever is causing your problem will likely be ID'ed. 
Attempting to 'hunt' (Buckshot approach?) for the problem is not the way to go about dx a DDEC system.
You may cause additional problems dinking around with all the sensor wiring.   
Since the CEL has been set, the codes are stored.   Do you have access to a DDEC II Prolink?  That's a nice tool to use. 
Download the codes.  Act only on those items.   Check the wiring for the problem codes.  The wiring or loose connections are typically the cause, and not failure of the sensors.
Each time you unhook a feedback sensor, you'll set a new code.  Eventually, you'll have to clear everything and start over.
Has any recent work been done on the engine or anywhere on the bus that could affect the DDEC wiring?   If so....that's where you could start?   
JR

JR Lynch , Charlotte, NC
87 MC9, 6V92TA DDEC, HT748R ATEC

"Every government interference in the economy consists of giving an unearned benefit, extorted by force, to some men at the expense of others."

Ayn Rand

Cary and Don

Ours was doing the same thing.  It turned out the fuel filter was a little loose.  Not loose enough to leak fuel, but just enough for the engine to shut down. A little turn to tighten, and it ran better than it had since we got it.

Don and Cary
GMC4107
Neoplan AN340
1973 05 Eagle
Neoplan AN340

hargreaves

The oil pressure sensor is based on certain pressures at given rpm's. the scale is in the manual. if the computer does'nt see the proper reading from the sensor at the particular rpm, it will shut down the engine. The sensors go out of range quite often. Detroit Diesel had a bad batch in the late 1990's. The alternator electrical field would send them out of range.   If nothing else works, I would change the sensor.    Good luck.     

Gerry
now as of Feb 2012 series 50 B400  . Sunshine Coast British Columbia

Sammy

You must remember to perform basic mechanical checks first, even though it is a DDEC controlled engine.Don't let the fact that it is computer controlled fool you.
If you still have the problem after that, "Flash" the trouble code and post it.
Good luck.