8V92 Won't Start

[Skykingrob]

Hi All
With the "cheap" price of diesel, I decided to fill my tank to the brim. But after doing so, the crazy engine won't start. It turns over like crazy without a fire. I checked the secondary fuel filter, completely full, which eliminates fuel from the equation. Very frustrating because it ran great just 1 week ago on 1/2 tank and now that the tank is full, no start.
Does anyone know if Prevost has an overfill cutoff built into the tank? I looked in the Prevost owners manual, the maintance manual and the detriot 8V92 book without finding it mentioned. Just trying to think of all possibilities. The block heater is on, the engine is toasty warm since it is 27 degrees and snowing all day. But no starting.

Rob
91 Lemirage XL
Missouri

[white-eagle]

i put just a minor squirt of ether into mine to start this morning.  Did you try that?  are you seeing any smoke, does it sound like occasional kicks, or just wasting battery juice?  maybe just a touch more info would help some of the real experts.

i just know mine needed a little help.  i had the block heater on for a couple hours yesterday before trying and just wouldn't fire.  ether caught right up and on.

today a little warmer, but no block heater.  again, just a quick squirt into the air filter and up she jumped.

[luvrbus]

Bob, is a DDEC or mechanical engine   

good luck

[Sammy]

Never saw a fuel overfill cutoff on the ones I worked on.Never even heard of such a thing on coaches.
IF your bus has DDEC (electronic engine controls) check the fuses and circuit breakers in the battery compartment (curbside, small door in front of drive axle). Let us know, can provide more help if needed.

[Dallas]

If it did run, and now it doesn't, you might want to check to see if the engine shut down lever is stuck in the "Off" position on the governor.

Good luck!

Dallas

[Ericbsc]

My 8-71 did the same. Mine lost prime. If you removed the filter you may need to reprime. I bought a 12v pump at auto store. Disconnect the fuel return ( the small one.) Pump fuel from fuel can thru both filters until it comes out the return line. Reconnect everything and try it. That worked on mine.

[Skykingrob]

Hi Folks
I thought it was a lost prime situation. That is why I checked that first. The is an on/off valve to prevent loss of prime that I shut off before checking the filters. Filters completely full. So looks like fuel is not the issue.
I read the manual about the fuel cutoff. I checked that and it looks okay.
I had been messing in the fuse box so I did check the fuses, but alas, not that either as all are in the on position.
Sorry for not mentioning it, it is a DDEC.
I grew up on a farm and we used to use ether until I saw an engine explode after injecting some, certainly don't want to do that to my engine so No, I didn't try that. The engine just spins like crazy with good batts. No smoke of anykind. Not even anykind of indication like it might fire. It acts like it is fuel problem but I can't prove it given the full filters.
Thanks for the help. At least I got some ideas, which I have already checked and sounds like next step is to call in the high priced DD shop to see what they can do with it.

Rob
91 LeMirage XL
Missouri

[Nick Badame Refrig/ACC]

Hi Rob,

I would do as Dallas has said and check the shut down lever on the govener. Fully reset it by pulling on the lever.

Good Luck
Nick-

[JohnEd]

Rob,

I sympathise with your wanting to be safe with the engine.  I think you are in the minority on the either phobia, however.  It is made to start Ds and the label says Starting fluid and it is sold everywhere.  I have no doubt that it can be misused and damage an engine.  Maybe follow the directions on the can?

When in the USAF I was blessed with the collateral duty of "handling" the emergency D generator.  It was never connected to the radar power panel but for a year I went out once a month and started that rascal.  Rain or shine, hot or cold.  There wasn't a single solitary fool on that mountain that had a clue about D's including me.  That either gave me pause so instead of having one of my airmen risk it all I did the job.  Lead from the front, right?  So that pig never ever started 'WITHOUT" either....even in the hottest 80 degree weather.  It also never failed to start WITH either.  It would quit the moment you stopped squirting the either for the first couple minutes.  Needed 2 big cans every time and I kept two cases for emergencies.  From what I know now I had my life on the line and I think I suspected it back then as I sent all my men back in the Tower and had only one standby 30 feet away with a fire extinguisher.  Never a problem.

Now lets hear how stupid I was and I suspect that that is the truth.  Was 30 feet far enuff?

John

Now wait....did you say it used to start up just fine?  Forget the either on this one but in the future?

[white-eagle]

Rob,

 It would quit the moment you stopped squirting the either for the first couple minutes.  Needed 2 big cans every time and I kept two cases for emergencies.  
John

when i said ether, i meant a 1/2 second squirt into the air intake, then walk over and hit the rear start button.  i'm still on the first can i bought 2 years ago and it's a least 3/4 full. 
John, i think we're lucky you're alive!!!

[JohnEd]

I said I had that "feeling" and I got all the "kids" out of harms way.  I am lucky to have lived thru a lot of stuff I volunteered for let alone what I WAS ORDERED TO DO AGAINST MY WILL AND BETTER JUDGEMENT. (HIT THE CAPS KEY).  Thanks for the "heads up!" though.  Better late than never ever.

John the survivor

[JackConrad]

Rob,
   If it is a DDEC, the fuel exiting the injectors is controlled by the DDEC.  No white smoke while cranking means no fuel exiting the injectors.  Since fuel goes from primary filter to fuel pump and then to secondary filter before heading to the injectors, it sounds like fuel is getting to the injectors.  Sounds like it may be something with the DDEC?

[Busted Knuckle]

Rob,
OK now that I know it is a DDEC, I can help ya! The shut down cylinder on the governor Dallas & Nick mention is not there on a DDEC, so that ain't it!
Now do ya wanna know for sure what it is before digging & looking for a the 2 12V in-line fuses ***SOMEWHERE*** between the batteries and the DDEC unit? Or do you wanna start at the batteries and check every lead, wire, connection, distribution panel, everything between the batteries and the DDEC unit itself on top of the engine?
OK first of I have never had to find them on a Prevost! But on the DDEC equipped SETRA's, MCI's, & 1 Eagle that I have dealt with (& I did have a DDEC Prevost that was hanging out recently for maintenance, but never needed to find the fuses on it, just had to be sure the 12V power was turned on above the batteries! and don't ask how I know that! LOL!) the DDEC's have all been 12V.
And on all but the Eagle (which was 12V anyway), the in-line fuses were on 2 lonely wires in the battery compartment. Now on the first SETRA we owned I had intermittent problems with these fuses until I replaced the fuse holder itself, then no problem!
On the Eagle I had the opportunity of working on there was a fuse in-line to the DDEC unit and it had been blown for "EVER" as the owner stated. "But hey that can't be the problem I wrapped it with a gum wrapper, and it's worked every since!" Yup you guessed it I took the dried up crispy funky foil paper out & stole a fuse out of the CB radio and walla it started right up! $100 service call over a piece of gum wrapper! (I didn't charge him for the fuse since I took it from his CB cord which was the ONLY glass fuse we could find!)
So somewhere your DDEC is not getting it's 12V or it has gone south itself!

Now every great once in a while my silly 60 series will crank like mad with no start I mean just out of the blue and very rarely happens, but it has happened at night, in the cold freezing snow, & a hot sunny day. But when it does it I grab a can of either and spray it on a count of 1-2-3 into the breather and then hit the rear start switch and it fires right up. And no problems for a long long time! I have looked and looked but not found the culprit here! I guess when it becomes a regular problem or I can't get it started then I'll track it down. But as irregular as it is I can't find it because it only happens when I don't have time to tear into it and find the issue!

Good luck and feel free to make a phone call to me or any other bus nut, (Sammy you listening since you are the PREVOST tech here! LOL!) before calling the high priced DD shop! Our prices are better and you'll learn more! LOL! FWIW   BK 

[CindyandJohn]

Rob,

Just a thought... I had start issues after my Eagle sat a while... I have a 6V92 in it... The outcome was - a stuck Skinner Valve (I think thats what its called) its the shut off operated by air. It needed some lubrication to get itto retract, things were fine after that. I'm no expert but I did alot of research to find the issue... Hopefully it's that easy.

John

[Busted Knuckle]

Rob,

Just a thought... I had start issues after my Eagle sat a while... I have a 6V92 in it... The outcome was - a stuck Skinner Valve (I think thats what its called) its the shut off operated by air. It needed some lubrication to get itto retract, things were fine after that. I'm no expert but I did alot of research to find the issue... Hopefully it's that easy.

John

John great thought and by all means thanks for sharing it with him. But since Rob's is a DDEC it is not the same, and doesn't use the skinner valves! FWIW   BK