92 Prevost DDEC 2

gyoder · March 03, 2013, 04:25:07 PM

Quote from: robertglines1 on March 02, 2013, 07:45:14 PM
ck this: curb side rear bay, see if there is a separate switch on the ceiling that needs to be turned on also. Also a reset button on it. Also ck fuel pressure switch left rear side of engine for loose wire. Also low coolant will let it crank but not start. Level must be above level of sensor located thru and above left rear engine door-look up. ???orignal seated coach?? converter?? xl?? ck fuse holders for corrosion. Bob

didn't find a switch, checked the fuel pressure wire,, the coolant sensor was setting a code so I replaced it but still will not start,, it is a converted coach,, [country coach] check all the fuse holders and no corrosion, I pulled the ECM to send it off to get it checked

thanks,,

gyoder · March 03, 2013, 04:31:01 PM

Quote from: luvrbus on March 02, 2013, 05:14:34 PM
If it is turning over as you say the transmission has nothing to do with it, you have no power to the injectors is the problem could be a bad sensor by pass each sensor and see if it fires are you sure the guy hooked the leads up after changing batteries ?
Those are 12v only if he gave it a 24v jolt then it will be the fuses

I have a friend that has scanner and he bi passed all the sensors and still no go, yes I re-hooked the batteries and they are correct now,,

gyoder · March 03, 2013, 04:35:32 PM

Quote from: stevet903 on March 03, 2013, 06:28:40 AM
Turn the key on, do the Check Engine and Stop engine lights come on for about 10 seconds and then go off? When it stops, is the stop engine light on? If they come on and go out, it means that you have power to the DDEC system, and there are no codes. If the lights stay on for 20 or 30 sec and then go out, you have a historical code. If the stop engine light is on when it stops (or it doesn't start and the light is on), the DDEC system has shut it down. There are three things that will shut you down -
Code 43, Low Coolant, Code 44, Oil or coolant high temperature, or code 45, Low oil pressure.
The transmission ECU should not affect the ability of the engine to start.

Do you get any smoke while cranking? If it hasn't run since 2008, I'd put new filters on and be sure they are full of fuel and the engine is primed.

we have full power to the ECM system and no codes,, no smoke when cranking,, we put all new filters and I have an electric pump hooked to the fuel feed and took the return line back into the container and let it pump and circulate new diesel for 30 minutes

gyoder · March 03, 2013, 04:37:25 PM

Quote from: expressbus on March 03, 2013, 08:47:13 AM
Going to the bus barn this afternoon. I'll take a picture of a relay that kept mine from starting spring a year ago. The engine would turn over and produce whitish smoke but would not fire. The relay (mechanical) is inside the large electrical box attached at the rear of the engine bay. It is on the left hand side of the box in a row of relays. On mine it was the center relay that a friend tapped while I was turning the engine over and it fired right up.

I'm hoping that is the problem with the coach you are looking at but I can't say a gentle persuasion tap will free your stuck relay. You might have to get a new one from NAPA.

thanks

gyoder · March 03, 2013, 04:39:08 PM

Quote from: Ace on March 03, 2013, 03:00:28 PM
Ok great, you found the two fuses laying on top if the batteries and you say they are good! How did you check them? If you made the mistake I made by merely looking at them, then please take a volt meter and on top of each fuse there are test holes where you can check to see if voltage is in fact crossing the fuse. Mine looked good but one fuse was blown and looking at it I couldn't tell because the break was way down below the bottom and very very hard to see! Check them with a volt meter to absolutely sure!

Sent from my iPhone using Tapatalk

I took the the holder apart and just looked at them,,i will go back and check them with a volt meter
Thanks,,

gyoder · March 03, 2013, 04:44:35 PM

Quote from: expressbus on March 03, 2013, 03:48:32 PM
gyoder,

Here are two pictures taken this afternoon at the bus barn. One shows two relays, the other the location of the relays. The relay in the black plastic case is the one that was keeping my 8V92 from starting spring one year ago. The relay in the metal case is an original relay since they supposedly do not come with a metal case anymore. The relays are inexpensive and available from NAPA and most likely other parts houses. Having experienced the condition you speak about when the coach sat for 4-6 weeks I'm thinking that the coach you are looking at could easily have a hung relay. I was told they control something to do with the setting of the fuel racks timing but don't hold me to that.

Just sayin' ...

Is there some tester I can buy to check these relays? Or do I just go and start replacing them?

gyoder · March 03, 2013, 04:46:24 PM

Quote from: wg4t50 on March 03, 2013, 04:02:35 PM
In our experience, not DDEC, but Cummins electronic engine and control systems, when someone connects the DC reversed, you will have at least blown fuse, smoked diodes, and from there is get real costly. As said, don't know the DDEC, but other computers do not like reversed DC, also most likely took out the battery belt driven alternator too.
ALways fun and expensive games when you see things arcing
Dave M

Thanks Dave,, I have checked everything I can visually without replacing all the relays, yesterday i pulled the ECM and I am sending it off to get it checked

robertglines1 · March 03, 2013, 04:54:55 PM

We are just passing on problems members or ourselves have had. One member had new fuses there and the problem was in fuse holder. New fuses are cheap. If you want to try the prevostcar web site use K-747 # that is a universal # that should get you to 8-v92 wiring of that vintage. I think I might have a book at shop if I get up that way I'll check Look for a vanner and see if your ddec feed is fed off it. Sometimes if polarity is reversed the breaker on vanner is tripped. No reason for that but it has happened . Do wish you luck with your venture. Bob

gyoder · March 03, 2013, 05:10:49 PM

Quote from: robertglines1 on March 03, 2013, 04:54:55 PM
We are just passing on problems members or ourselves have had. One member had new fuses there and the problem was in fuse holder. New fuses are cheap. If you want to try the prevostcar web site use K-747 # that is a universal # that should get you to 8-v92 wiring of that vintage. I think I might have a book at shop if I get up that way I'll check Look for a vanner and see if your ddec feed is fed off it. Sometimes if polarity is reversed the breaker on vanner is tripped. No reason for that but it has happened . Do wish you luck with your venture. Bob

Thanks

robertglines1 · March 03, 2013, 05:40:36 PM

wiring diagram prevostcar site wiring diagram use unit # L-1685 was delivered to converter's Should be close to yours. Bob

gyoder · March 03, 2013, 06:48:48 PM

I have just found a relay tester, I have wanted one for a long time and this is a good time to get one

ESI 190 Electronic Specialties 190

robertglines1 · March 03, 2013, 08:35:50 PM

Basic ck: switch position front key on rear engine compartment panel toggle switch has three settings rear off front if starting from rear front must also be on. center position on rear toggle kills system all together. Not trying to insult your knowledge just sometimes we miss the simple. Bob

gyoder · March 04, 2013, 07:14:30 AM

Quote from: robertglines1 on March 03, 2013, 08:35:50 PM
Basic ck: switch position front key on rear engine compartment panel toggle switch has three settings rear off front if starting from rear front must also be on. center position on rear toggle kills system all together. Not trying to insult your knowledge just sometimes we miss the simple. Bob

you never insult my knowledge by trying to help

Thanks,,,,

Gerry H · March 05, 2013, 07:33:15 AM

Hello: Just a thought, but seems everyone is committed to an electrical problem due to various things happened or happening.
Diodes are typically engineered into the systems to prevent reverse voltage damage. Is it possible that it's a lack of fuel issue? Just following along. Good Luck Gerry H

gyoder · March 05, 2013, 10:10:01 AM

Quote from: Gerry H on March 05, 2013, 07:33:15 AM
Hello: Just a thought, but seems everyone is committed to an electrical problem due to various things happened or happening.
Diodes are typically engineered into the systems to prevent reverse voltage damage. Is it possible that it's a lack of fuel issue? Just following along. Good Luck Gerry H

I changed all the filters then hooked an electric fuel pump to the system, I disposed of the original fuel then I connected the return back into the container of new fuel and let it circulate for 30 minutes until I were sure that all of the air was out of the system.
The mechanic that was working on this project before me cranked it on starting fluid. This tells me we have a fuel/injector problem. I pulled the computer and its getting checked out. Thanks