Good evening,
i am now stranded in Longview TX. Dropped the buss off two days ago to a fabricator to build and bolt on a hitch. Went to pick it up today and it will not start. They moved it on the yard yesterday, but not even a promise today. Is there anything they could have done, ie flipped things in wrong order? They did leave the chime lights on, but it seemed to crank just fine till i just about killed the battery. Here are the details:
- Reliabilt 03' 6V92 engine
- Single fuel filter with a clear cover, about 1" of fuel visible on the bottom.
- Engine turns and with small squirt of magical "E" runs for few seconds.
- Im sure there is a emergency shut off of sorts, but it isn't a flap or anything that i can see on the air side, is there a fuel shut off and where might that be?
- Maybe somehow lost prime? Any easy way to prime or check?
Id love to get it running by myself and not call Steward and Stevenson, but, at least they are in town...
maybe someone siphoned the fuel. Or shut the 12 V switch to ddec off.
Humm. Did they weld on the chassis without putting the ground as close to the area to be welded? Or not disconnect the grounds to the ECM?
--Geoff
Hi Beachfinn, is there an emergency sto, shutdown engine switch on the dash? Mechanics that don't work on buses, flip switches when trying to start them up, if they don't know what their doing, happened to me once. Someone here will tell you the procedure to rest the flap , if you have one, lvmci
If there is only one inch of fuel in the filter and it runs on either, fuel is not getting to the engine. The fuel filter should be full
Art
maybe someone siphoned the fuel. Or shut the 12 V switch to ddec off.
- the fuel gauge still reads 3/4 full, theres a pad lock on the fuel bay door, so that should be ok. 12v switch to DDEC, first im hearing of it....
Did they weld on the chassis without putting the ground as close to the area to be welded?
- there should have not been, and they say they did not weld anything on the bus.
is there an emergency sto, shutdown engine switch on the dash?
- i have not found an emergency stop on this bus. I don't think it exists on DDEC3?
If there is only one inch of fuel in the filter and it runs on either, fuel is not getting to the engine. The fuel filter should be full
- and i think this is correct, i recall always observing it with just a slight air space at very top. Should the top just screw off and manually fill? the filters were changed by Darby Diesel about month ago...
The fuel filter sounds like it is a Davco type, which should not have fuel to the top. As the filter gets dirty, the fuel level rises. Once the fuel level gets too the top inch, its time too change the filter.
Have you checked the fuses in the battery compartment? It's a long shot, but I once blew one of those fuses on the left side of the battery compartment, they control the DDEC computer. The bus would not fire since the computer didn't have power.
There it's no air box flapper on a DDEC engine, those are only on mechanical engines.
They might have flipped one of the rear control switches as the left side of the engine. One switch should be on "run", the other should be on "front" if you are trying to start from the front switch.
The rear switches should be fine, I was starting it from the rear.
I'll check the fuses, I'll have to get a small shreader valve compressor to air up, as all my tools are in the belly. Lesson one; hook up compressor to air up from the genset power. Honestly, it could be worse, I don't have to be anywhere, might as well learn DD, I have few days to spare...
Yes, those pesky air operated baggage door locks. A good idea for buses that are always running, but in my situation, being parked for long periods of time I removed them.
Quote from: scott332 on May 14, 2016, 07:29:22 PM
Yes, those pesky air operated baggage door locks. A good idea for buses that are always running, but in my situation, being parked for long periods of time I removed them.
That was one of the first things to go bye-bye on mine.
Yes, air lock baggage doors, not good if engine not running, lvmci...
If it's a FuelPro filter unit, it's not supposed to be full, so it's probably not a fuel issue.
Sounds like maybe they welded on the chassis and fried the DDEC.
I like my bay door air locks. I made some clips that I can install over the ends of the cylinders to keep them from locking automatically. Simple and effective.
I installed a small air pump and connected it into the air locks so I can unlock them when the bus has no air.
Check to see if the stop engine and check engine lights come on when you turn the switch on. If they are not coming on you don't have any power to the ecm.
Jack
Check the position of the fuel shut-off lever that is controlled by the skinner valve (assuming the DDEC3 version has this setup). It might be hung up and not releasing the shut-off position. As the others have mentioned, if you have the single fuel processor and the filter is fairly new, the visible level will be low, but if you know that the level was higher recently, then something changed. It would not hurt to add fuel through the top in case you lost prime for some reason. The filter will find its correct level after it is running.
As mention if the check engine lite doesn't come on you have no power to the ECM start there then we can help you,
It's probably a ground if they tied your trailer plug into grounding stud for the ECM or even low on coolant
Be sure that the lights come on and then go off. If the check engine or stop engine stay on let us know.
Jack
Thank you all. I'll start with the check engine etc lights. I'll post findings after I find someone to open the gate to the shop.
Ok, at the bus; there is no check engine light on the instrument cluster. I have a tiny air compressor hooked up to the Schroeder valve in engine side door to air up.
Checked ddec fuses in battery compartment; all good. Measured voltage when cranking and 12v drops to ~9. Hooked up to pickup truck to try to get a better charge in...
Any other ideas? I'll try to crank after a little while and see if 12v stays higher...
Are the switches in the back set to front start? The check engine light should be on when the step light switch is on and the master switch is on. It should stay lit when the alarms are ringing in the front for low air.
Switches in the back are set to front start and run position, the instrument cluster doesn't seem to have a check engine light.....and on another note there is no low air buzzer sounding, even though air is still at 72.
The MC 12 has a check and stop engine light. They more than likely are not coming on. They will come on each time you turn the switch on and only stay on for a few seconds. If these lights don't come on don't wast your time trying to start the engine.
Jack
On mine the stop engine light is on the bottom row of indicator lights 3 rd from left, check engine light bottom row 4 th from left. Those both should come on when the switch is first turned on. Try borrowing bulbs temporarily from another position.
https://db.tt/nm1BFmt1
Here's a link to the Dropbox picture of the instrument light cluster. What am I missing?
Checked the 3rd and 4th bottom row from the left bulbs, both are working but not illuminating.
Your bottom row is not the same as mine. Are you sure the welders didn't weld on the bus? Most welders know to unplug engine computers, but some don't bother, taking the chance nothing will go wrong.
Try turning on the master switch, and switching on the engine override three times ( it's a momentary switch). Without hitting the engine start. On mine the stop engine light and check engine lights will flash computer error codes. If any lights flash, count the flashes between the pauses. Write the flashes down if anything does. They will repeat until you switch the override once more.
If you would like to call I may be able to help. 863-2063-3838
Jack
you said 9 volt to ddec... it shuts itself off below 11.6 volts.. Bad battery? one bad cell can do it. Below 11.6 it does not talk to injectors. can spin but without injectors has no fuel. ck your batt individually chances are the low batt is the one that feeds ddec
what Robert said ... keep charging and stop cranking... a low battery can kill more stuff than most can afford ...
With a low or bad battery he should be getting a code 61
WOOHOO !
with help from Jack, it's running. I'll post more detailed report later, but here's the short scoop. I checked the main power connector to DDEC (Two 12v red wires and 3 black grounds), these are fed directly from battery via the two fuses in the battery compartment. All checked fine. Pulled the large connector next to it (with a 1/4" screw holding it). As Jack said there should be 12V coming from the ignition switch to a pin (wire stamped with 439). No voltage; so its either the chimes switch, ignition switch, but more likely a relay in the bus rear or stop/run switch in the engine compartment. I put a jump wire from DDEC 12v feed to that pin, and voila' started right up. Drove it back to the hotel with everything normal. Now heres the biggest lesson of all: that pin wired directly from battery...the bus will not shut down even if you throw the main switch. So in essence, as long as you have 12v to the DDEC and that pin hot, it will run.
Thank you all for your help, what an awesome feeling when it fires up :)
It has to have the ground also,they are not as complicated as most think 2 wires and they will run.I am late to electronic control engines game but I have just about figured out where the old mechanical engines needed just air and fuel to run, the electronic engines just need a power supply and a ground to run ;D
Hey I didn't even know there were such thing as a DDEC III two stroke??
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Quote from: Scott Bennett on May 15, 2016, 07:11:17 PM
Hey I didn't even know there were such thing as a DDEC III two stroke??
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They have a DDEC IV to work with all the other transmission,I have a 8v92 DDEC IV in my shop now 550 hp factory setting a sweet engine fwiw
Quote from: luvrbus on May 15, 2016, 08:03:24 PMThey have a DDEC IV to work with all the other transmission,I have a 8v92 DDEC IV in my shop now 550 hp factory setting a sweet engine fwiw
Wow, nice. I had no idea such a thing existed for road use. Sounds very sweet indeed.
Sam,
I'm happy to hear that you found how to put 12V onto pin 439 to get the engine to run (but not stop). I had a weird situation recently that possibly may be relevant to you. My main 100A feed from the start batteries and starter had a very badly corroded terminal in its Class H fuse holder, so much so that the engine died when I turned on the headlights! I had to completely rebuild the fuse holder, crimp new ends onto the cables, and while I was at it I also replaced all three Cole-Hersee solenoids because they were 25 years old and in umknown condition. Having done all this, I now have absolutely no voltage loss whatsoever between the start batteries and the front junction box and start switch, even under load (I had almost one volt loss before!). Essentially I have now replaced or cleaned every terminal and connection between the batteries and the DDEC, including all the grounds. DDEC works well provided it has sufficient voltage - any poor connections will cause problems sooner or later. Yes, it's tedious groping around inside the engine room to do this work, but it's still better than having everything completely die while driving. A good VOM is definitely well worth it!
John
And here was the issue, fuse/circuit breaker in the back electrical box. replaced with inline fuse. I'll replace with original (and the one next to it) on my next visit to MCI (need windshield). Been living in the bus and traveling 3K miles since then, I'll update my build thread soon with all the great stuff that has happened and been done.
One more question, have you found the check and stop engine lights? They are there somewhere.
Jack