| Author | Message | ||
| don (Bottomacher)
Registered Member Username: Bottomacher Post Number: 179 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
After sitting for several months while I built a new instrument panel and cockpit area, my 6v92 won't start today. Everything electrical that I can find is normal; I have fuel in both filters and it squirts out the flare fitting that is capped on the far side of the secondary filter when I crank the engine. The maintenance manual has NO troubleshooting information, so here I am. Has anyone seen all six injectors plug solid from simply sitting? The engine ran really well before, and I just had Luke run the rack about 3000 miles ago. Absolutely no smoke is coming from the tailpipe, and I am clueless, normally an understatement. Does anyone have any idea? Thanks Don | ||
| Ednj (Ednj)
Registered Member Username: Ednj Post Number: 198 Registered: 3-2003 Posted From: 67.85.237.82  Rating: N/A |
Don, Check your air intake> | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 440 Registered: 8-2006 Posted From: 74.32.90.214 Rating: N/A |
Don, I take it you have mechanical 692 check your shut down lever and make sure it is not stuck closed and also check your linkage going to the rack.If you engine is equipped with a emergency air shut off check that also good luck (Message edited by luvrbus on June 29, 2008) | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 457 Registered: 10-2006 Posted From: 72.66.162.174  Rating: |
"check your shut down lever" I agree with Luvrbus. What is your shutdown solenoid doing? I don't think a V92 has an emergency flapper though. | ||
| don (Bottomacher)
Registered Member Username: Bottomacher Post Number: 180 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
I don't have an emergency shutdown.  | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 140 Registered: 12-2000 Posted From: 166.214.134.183  Rating: N/A |
Don it is just a shut down lever on top of the engine. It is not an emergency shut down. Mine stuck and I had to use a J-hook devise to pull it open from the rear of the coach. | ||
| don (Bottomacher)
Registered Member Username: Bottomacher Post Number: 181 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
My intake housing has a threaded plug in the hole that the book shows as the flapper shaft hole, to which shaft the reset lever is attached. I just looked again, and I can't see any hardware attached the the housing anywhere. I'm going to install a new turbo soon, and I can look inside the housing at that time, but I still can't see how a flapper could be activated without some external device. | ||
| Sammy (Sammy)
Registered Member Username: Sammy Post Number: 84 Registered: 8-2005 Posted From: 68.237.192.11 Rating: N/A |
Don,check the rear run and rear start switches - make sure all are in proper position.Check the engine stop Shrader valve too. The shaft of it could be stuck "out" , or extended. It pushes against a small lever on top of governor cover (next to engine throttle) and this puts injectors in a "no fuel" position. Good luck. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 441 Registered: 8-2006 Posted From: 74.33.40.243 Rating: N/A |
Don, if you don't have the hardware with a solenoid on the housing there is not a emergency air shut down or flapper as some call it. check what Sammy and JCB suggest and keep us posted on the outcome | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 2060 Registered: 1-2001 Posted From: 75.108.85.14 Rating: N/A |
I think I would give her a whiff of ether and see if she fires. Richard | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 482 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Don, 92 series engines DO NOT HAVE FLAPPERS, or whatever people wish to call the emergency shutdown device! That said, I think I read into what you said that the engine cranks and doesn't fire? I also read you said no smoke, which means no un-burned fuel, which in turn means no fuel being injected. Causes can only be three, assuming yours is a mechanical engine. One, the stop lever or cylinder has stuck in the stop position. Two, no fuel available to the injectors. Three, condensation has formed in the fuel tank, and as water is heavier than diesel, it goes to the bottom, and will be picked up first, and won't fire when injected. If you're DDEC, probably electrical problems. Happy hunting, and please tell us what you find. Regards, George | ||
| Cable (Fe2_o3)
Registered Member Username: Fe2_o3 Post Number: 24 Registered: 10-2004 Posted From: 71.112.211.206 Rating: N/A |
Saw a similar problem on a Prevost..Turned out the batts. would spin the engine but not trigger the DDEC.. Charged batts. Solved the problem..He had run one batt. low with house hardware while parked..Just a shot in the dark...Cable | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 487 Registered: 1-2005 Posted From: 72.189.64.251  Rating: N/A |
George I believe that you'll find that DDEC 6v92 DO NOT HAVE FLAPPERS but MUI (mechanical injectors) 6V92's do Pete RTS/daytona | ||
| gary throneberry (Garhawk)
Registered Member Username: Garhawk Post Number: 17 Registered: 3-2007 Posted From: 72.156.222.253 Rating: N/A |
hi don you say there is absolutely no smoke coming from the exhaust when you crank the engine. leads me to believe an exhaust problem might be lurking. that was my problem recently, with almost the same situation as yours. hang a piece of plastic sheeting (piece of garbage bag) over the end of the exhaust pipe. when you crank engine, the sheet should stand out vertically, even if the engine does not fire. if not, start checking back toward the engine for exhaust obstructions. in my case, it was a clogged catalytic converter. disconnect exhaust piping immediately behind blower (just enough for plenty of air to excape) and crank engine. that was my test, the engine fired right up and, identified the muffler as culprit. gary t'berry '89 rts 40er | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 442 Registered: 8-2006 Posted From: 74.33.40.243 Rating: N/A |
George, the air shutdown was a option for 92 series engines most all of the 92's in emergency vehicles had them along with the industrial type like construction equipment and deck engines for oil drilling.My 92 series DD manual shows how to rebuild the unit I have one on my 8v92 I set just to stop someone from starting and driving it away cheap theft protection for me fwiw (Message edited by luvrbus on June 30, 2008) | ||
| Bruce Henderson (Oonrahnjay)
Registered Member Username: Oonrahnjay Post Number: 245 Registered: 8-2004 Posted From: 72.12.39.78  Rating: N/A |
Cable (aka "Mr Oxide") wrote: " Saw a similar problem on a Prevost..Turned out the batts. would spin the engine but not trigger the DDEC.. Charged batts. Solved the problem..He had run one batt. low with house hardware while parked..Just a shot in the dark...Cable" __. This is a good point for anyone with an "electronic" injection engine. On most of them, the designers realized that it would be possible to "flood" the engine with disasterous results if the system were to inject fuel if the engine were not turning over with sufficient RPM's to ensure ignition (this applies to diesels and gassers). If the batteries aren't strong enough to spin the engine fast enough to trigger the electronics, it's going to act as if it's not getting *any* fuel ... because it isn't. __. If your engine tolerates starting fluid well, often all it takes is a little whiff. If the engine will kick over on the ether, it almost always will spin quick enough to trigger the electronics and the engine will then run on its own. (But I'm really leary of starting fluid, used properly is can be a help but a lot of people have done lots of damage with it, so be careful.) | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 182 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
Sammy, I think you may be referring to a Skinner valve- Schraders are normally air or refrigerant valves. In any event, the shaft is withdrawn and the lever moves freely at least 1/2" or so. The is engine is NOT DDEC, and the starter is spinning it quite fast, since the batteries are fully charged. It has no catalytic converter. It is about 85 degrees here and I'm afraid to use ether. There has never been a starting problem with this engine, and it ran beautifully when I parked it. I'll try a bag over the tailpipe later today | ||
| John Lacey (Junkman42)
Registered Member Username: Junkman42 Post Number: 41 Registered: 3-2007 Posted From: 69.19.14.42  Rating: N/A |
Don, detroit placed a device on the engine for starting capsules. Put a shot of ether in the device that was placed for just that purpose. Try it only once. More than once is possibly a problem. My two cents. John | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 443 Registered: 8-2006 Posted From: 74.33.40.243 Rating: N/A |
John, you won't find that on a 92 series from DD | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 183 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
Well, I tried the tailpipe test- it filled the 30 gal. trash bag in about 2-3 seconds of cranking. I believe I'll remove the valve cover and open a fuel tube to bleed it. I'm pretty convinced that no fuel is hitting the cylinders. | ||
| Don Evans (Doninwa)
Registered Member Username: Doninwa Post Number: 130 Registered: 1-2007 Posted From: 208.81.157.90  Rating: |
Since you were working on the electric stuff up front I would double check things like the low oil and over temp shutdown. I don't think think they should prevent starting if there is no air up. Since it is so warm you can direct prime with diesel instead of starting fluid to see it if will run. Start with just a little, don't want to over speed it. It is easy to prime our GMs. The fitting is right there when you open the engine cover. Don't know about others. Best to have it in a squirt can and spray it in while cranking. If you had the filters open or the "flare fitting" open you may have lost prime. Do you have a fuel pressure gauge at the secondary filter? Good luck Don 4107 | ||
| larry currier (Larryc)
Registered Member Username: Larryc Post Number: 186 Registered: 2-2007 Posted From: 207.200.116.13 Rating: N/A |
Prime it. Are you sure someone didn't steal all your fuel? | ||
| Cable (Fe2_o3)
Registered Member Username: Fe2_o3 Post Number: 25 Registered: 10-2004 Posted From: 71.112.211.206 Rating: N/A |
Fuel pump?...Cable..again | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 392 Registered: 10-2006 Posted From: 208.100.193.59 Rating: N/A |
There is usually a check valve that keeps the engine from bleeding fuel back to the tank. If you are going to open the system for a look ,open it first.You can also check weather the line from the tank to the check valve will let fuel pass. GOD only knows what the new fuel (or what ever passes for fuel) inside our old tanks. Bio Diesel is a very active stripper and may have ripped pounds of tank gunk loose. FF | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 184 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
I bought a new fuel pump yesterday. When it comes, I'll start at the tank, flush everything I can, prime and try again. This thing is making me mad... | ||
| Cindy and John (Cindyandjohn)
Registered Member Username: Cindyandjohn Post Number: 85 Registered: 1-2007 Posted From: 70.15.49.39 Rating: N/A |
Don, Here is a really simple thing to check... I have to admit I had ths problem once... but learned from it quickly! If you have an automatic trans like mine - I have push buttons on the dash - it needs to be in nuetral. I had it in drive once and it cranked till the batteries died but wouldnt do a darn thing to start.... Just my input of those little silly things we all do from time to time. Since you said you had the dash apart it might be possible the trans buttons are not in the right position. Just a thought, John (Message edited by cindyandjohn on July 01, 2008) | ||
| Cable (Fe2_o3)
Registered Member Username: Fe2_o3 Post Number: 26 Registered: 10-2004 Posted From: 71.112.211.206  Rating: |
Don; Don't let this get to you. You're in the best place to deal with it. Trust me, it's much worse on the roadside with traffic whizzing by...Don't ask. You've also got a wealth of experience at your finger tips. Relax, learn from our mistakes.... Cable...again | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 186 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
My shifter is a cable/lever device, and the engine won't turn over in gear. I have looked at and thought about every electrical doodat, interlock, sensor. etc., that I can find in the book. If it turns out that I did it when I rewired, I'm going to have to figure a way to kick my own butt and that's just going to make my arthritis act up and piss me off even more. | ||
| Jack Campbell (Blue_goose)
Registered Member Username: Blue_goose Post Number: 89 Registered: 5-2007 Posted From: 71.100.207.86  Rating: |
From what I have read, you have exhaust, the engine is turning over fast enough to start. You still have no smoke at the exhaust. When the engine is turning over not running the rack is open. If you have fuel and it dosn't start you should have white smoke. If you have white smoke it will start. Looks like the only thing it could be is no fuel. Jack | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 483 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Well, a couple of things to say: First off, there are three people saying to look at the emergency shutdown, EVEN THOUGH HE SAYS "NO SMOKE" IN THE ORIGINAL POST! An engine which IS equipped with a shutdown flapper will inject fuel, and as almost no air can get in, it produces huge clouds of grey to black smoke when trying to start. Second: 92 Series engines are equipped with spring-loaded racks, which prevent a stuck injector from holding the whole rack open and causing a runaway, so they do not come stock equipped with an emergency flapper. Pete has posted that "George, I believe you will find 6V92 DDEC don't have flappers, but 6V92 MUI (mechanical injectors) do." !!!!AFTER THE ORIGINAL POSTER SAYS "MY ENGINE DOES NOT HAVE A FLAPPER!!!!!!!" Someone else says correctly, "Flappers were an OPTION on construction equipment..." There are suggestions to check the rear start switch, and the trans neutral switch, and those posters don't rush to criticize another, so they get points, even though we must look to Don Evan's, and Jack Campbell's posts later on. As I said in my first post, no smoke=no fuel, period. To keep the picky people happy, I hereby revise my first post to read: 92 series truck and bus engines did not come standard with flappers. Am I saying read the entire thread before rushing to criticize others? YEP, especially when you're wrong! Now, let's get back to being positive, and troubleshoot this problem, as we have a lot more information! Don Evans has posted that "low oil, or high temp shutdowns should not affect starting because of no air pressure." Jack says fuel = white smoke, THESE COULDN'T BE ANY MORE CORRECT! This also applies to an auto trans with a neutral safety switch, which is not in neutral. Lets consider the consequences of this for a second. MOST of the shifters are air operated, and can't shift the trans with no air, which is why they won't let the engine stop in gear, as it means it would be in gear at the next start, and couldn't get into neutral with no air. Most of us know that our busses won't shut down with no air, and its kind of hard to rev up for air with an auto trans in gear, and the parking brake applied. In the post four above, (at least when I started this) the neutral switch is wired in the wrong circuit, it should disable the starter. That way you know something is wrong before you run batteries down, and overheat a starter? This doesn't apply to lever-cable operated shifters, they work all the time. Cranks, no smoke, shutdown cylinder retracted, lever moves freely, no flapper, warm day, inflates a trash bag, (which rules out a catastrophic cam gear failure) what's left? Either the fuel rack is stuck in the no fuel position from the shutdown last fall, or the delivery system is not delivering fuel to the injectors. Pull a valve cover, and see if the rack is free, and moves away from the no fuel position while cranking. If it does, then look to the supply system. A 5 gallon can with a hose directly off the primary filter rules out a multitude of problems. Read (rhymes with red) the thread, George (Message edited by George Mc6 on July 01, 2008) (Message edited by George Mc6 on July 01, 2008) | ||
| Sammy (Sammy)
Registered Member Username: Sammy Post Number: 85 Registered: 8-2005 Posted From: 68.237.192.11 Rating: N/A |
Might have lost it's prime for the fuel system. You mentioned it was sitting for some time. Not all Detroits will pick up enough fuel to prime themselves,just by cranking them.If fuel jumper pipes are airbound, you'll need to prime it. To prime fuel system you need to force fuel into the secondary fuel filter or the line that goes from the secondary filter to the head. This will force fuel into injector fuel pipes and fill fuel cavitys in the heads. Doubt it's a blower shaft, cause you'd see white smoke. If you have a mechanical tach drive on blower, crank engine and confirm it's turniing. If priming does not work, then I'd pull valve covers and see what's going on under there. Good luck. | ||
| Pete/RTS Daytona (Pete_rtsdaytona)
Registered Member Username: Pete_rtsdaytona Post Number: 488 Registered: 1-2005 Posted From: 72.189.64.251 Rating: N/A |
If your absolutely reluctant to use a small shot of either - then just have someone hold a gasoline soaked rag near the intake. If you don't want to do that - and you think maybe you lost prime - (I don't think so - IIRC you said you can see fuel if you break a line at the secondary filter (that's after the pump). But if that's not the case - use a garden sprayer at the input of the primary filter and force fuel thru the primary / fuel pump / secondary / rack or common rail (I forgot if yours is a DDEC) / and finally thru the return orifice and back to the tank - with pressure in the sprayer - try and start the motor Pete RTS/Daytona | ||
| J.C.B. (Eagle)
Registered Member Username: Eagle Post Number: 141 Registered: 12-2000 Posted From: 166.214.37.251 Rating: N/A |
How about an update on this. Have you got it started yet? | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 191 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
Not yet; still waiting for parts. I'll post when it starts. | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 195 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
I have primed the engine again. I still get absolutely NO smoke from the exhaust pipe. The starter turns energetically, and fuel flows freely through the engine and back to the tank. I assume that the rack is stuck shut. I don't know how to free it, and i don't want to bend or break anything. The GM book is fuzzy and says nothing that I can find about unsticking the rack. Does anyone know the procedure? Thanks again Don | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 485 Registered: 10-2006 Posted From: 153.2.247.31 Rating: N/A |
Take your valve covers off and look at, operate the rack, to see if something is sticking. Two bolts and they lift off. I even run mine with the covers off to work on it. In case anyone was wondering, the oil does not squirt out all over but just clings to the metal and runs back into the pan. A beautiful piece of machinery to watch operate. Give it a shot of ether and see if it will hit. Ether does not hurt it if you don’t go crazy with it. When they get tired and cold, ether will save your starter. Mine even has a place for an ether egg. (Message edited by barn_owl on July 27, 2008) | ||
| don goldsmith (Bottomacher)
Registered Member Username: Bottomacher Post Number: 197 Registered: 12-2000 Posted From: 72.15.86.59 Rating: N/A |
I believe the mystery is solved. First I want to thank all of you for your help and advice. I'm a pretty fair mechanic, but sometimes I'm looking at forty feet of confusion and the thought that it might be an electrical problem makes my knees go all funny. It is a governor problem, apparently. When I took off the valve cover and held the control tube open slightly (thanks, Dan), the engine started right up. It also died when I released the tube. For some yet unfiguredout reason the governor won't let it idle. But it happened while parked, so I don't expect anything is broken or even out of adjustment- just stuck. At least now I know where to look, and I can run the engine when I need a pacifier. More later, and THANKS AGAIN! |
