Ok, I know I need to do a little more work to my motor, but I'm trying to give myself a little hope here. :-\
I had the rack run this past winter and that was fine, but the ol'girl still doesn't like to start without a shot of ether or have the motor plugged in............ and it's probably about 80 degrees outside and she needed a little bump of ether. Bummer, huh. :(
The next thing- the guy who ran the rack for me said- was to compression check it and then maybe put in new injectors and bench them.
My question is: could the injector work help with the starting issue or is it just plain and simple that I need the bottom end gone thru? Just trying to give myself a little hope, but I'm afraid I already know the answer. :'( :'( :'( :-[
What's you guy's profession opinion :) and experience say?? I can take it. :'( :'( :'( :'(
I start hard in the mornings too,
Chaz
First off, can you answer a few more questions?
1) How's your cranking speed when you are trying to start?
2) What can you tell us about your exhaust smoke? Smoking for a bit, in the first few minutes after start up? How quickly does this clear up? What about smoke in the exhaust once your are up to temp and cruising? Smoke color?
WEC4104
Chaz,
I had a similar problem with my 8V71. Got rid of a couple of bad 8D's and installed a couple of brand new group 31's. I think the problem was the 8D's just did not spin the ole Detroit fast enough. Since I have had the Group 31's it cranks much faster and has started each time very quickly.
I hope this helps a bit, I know how frustrating these monsters can be at times.
Happy Trails,
Paul
Dreamscape
Quote1) How's your cranking speed when you are trying to start?
Seems to be good. I have 2 new 8d's and I even checked them to make sure.
QuoteWhat can you tell us about your exhaust smoke? Smoking for a bit, in the first few minutes after start up? How quickly does this clear up? What about smoke in the exhaust once your are up to temp and cruising? Smoke color?
Smokes pretty much in the beginning and for several minutes, but clears up. About 2 blocks down the road it's fine. You can just barely see the exhaust. In the beginning it's basically white or at least very light colored.
QuoteI had a similar problem with my 8V71. Got rid of a couple of bad 8D's and installed a couple of brand new group 31's. I think the problem was the 8D's just did not spin the ole Detroit fast enough. Since I have had the Group 31's it cranks much faster and has started each time very quickly.
I hope this helps a bit, I know how frustrating these monsters can be at times.
Thanx Paul. I'm not even sure how fast it should crank, but I would hope the 8d's would do ok.
Chaz
Chaz: If it is not cranking fast with new batteries, then you may have a dragging stzrter. You need to hear one that cranks properly to evaluate your own.
Chaz,
Diesel fires under good compression. At least that's how I understand it. The faster the crank the higher the compression build up. I am sure some else has better understanding of how it all works. I do notice mine spins a lot faster than it used to. I also rebuilt my starter and replaced some cables.
Paul
Chaz,
As was mentioned, diesel ignites from the heat of compression. To generate enough heat from compression requires enough compression of the air which is dependent on a couple factors. First no or very little leakage of the air from the cylinder (bad rings, leaky valves) and the engine spinning fast enought to compress the air quickly enough to get the neccessary temperature to ignite the diesel. Someone else may toable to expalin it better or in more detail. I am sure there are probably other factors, I have overlooked. Jack
Chaz,
As Stated injector or valve or rings or starter speed or any combinations so some diagnostic tips FWIW
Poor injectors tend to have a real knocking sound when the engine first starts up and will quit once warmed up or even quicker.
Rings open the Oil filler if the rings are really bad you can actually hear a slight popping sound (really bad) a lot of air can mean worn rings.
Valves ( a little harder to tell) at a warm bumping the throttle is there a tint of blue with the black (really hard to see).
Any one of those conditions can cause hard starting.
If you remove the injectors to be tested (best diagnostic) do a compression test then you will know for sure.
JMO
Skip
Ok so......... can injectors cause it to need ether or a block heater? If not, I'll just scrape that idea and hope for something like the starter not turning fast enough or something like that. I will be going to a bus ralley in Cincy next month so I can hear how fast one starts there I guess.
But.................... it's my guess the ol'girl is just weak. She does run pretty good tho, and I'm told to just run her, but I just like to have things operating as best as i can.
Thanx guys,
Chaz
Chaz
Your injectors can be worn or partially clogged up or just wearing out you can pull the injectors and have them flow tested and that will show the spray pattern if they are not atomising the fuel you will have starting problems thus taking ether to fire her off. If starter is pulling too many amps a snap on the batt cable meter will show you how many amps your starter is pulling.
There is more to starting a diesel than just a charged up battery so I would say a good electrical test is first order then if you need a flow test on injectors then a perfect time to do a compression test when inj are out.
Hope this helps.
LarryH
Chaz,
OF course start with the easiest to fix diagnose etc. first. Starter thing...
Bad injectors can make it very hard to start an engine. Weeping, poor spray pattern etc injectors can cause
a lot bigger problems down the road if they are not fixed. A weeping (solid stream popping off at less than spec pressure) can
eventually burn a hole in a piston. That is bad.
Just some info for thought.
Skip
Thanx guys!!!!!! I appreciate the info. I will start with the amp draw. (a buddy owns an auto repair and should have that equiptment) Then I may have the injectors gone thru and a compression test anyway. The more I think about it, the more I would just like to know. But hopefully it won't be as bad as I think. But......................................................... :-\
Thanx again!
Chaz
My 6V92 can set for a month and I can't hit the starter button fast enough. It starts before 1 revolution... When it's cold I plug in the block heater for a couple of hours and it starts the same, pretty much instantly.
Good luck,
Don & Sheila
I have an old gm with a 8V71 that had been setting for some time and once the starter was engaged it burst to life with enough smoke to run everyone off. Most will start on the first rev or so. batteries can't get the current to the starter if you have a bad connection.make sure your grounds are good at all points and then a voltage chec while cranking at the starter could confirm if there is a large voltage drop. A dragging starter will draw more current and show a larger voltage drop. Jerry
Chaz- I have a fresh 8V-71N (now turbo'd). But when I was at Grand Canyon last year about this time, it got down in the 30's and we sat for two days. I opened the rear engine door thinking I might need ether. I started to turn it over and it fired in about three revolutions with a big white cloud that disappeared in about one minute of idling.
If the injectors are not up to snuff, you'll get alot of black smoke before it fires (dumping raw fuel that is not atomized very well). If your rings are worn (which this sounds to me) then you might be able to get by with just replacing the piston rings and bearing shells if the cylinder liners are not worn excessively (if you can see the hone marks). I would get it done soon since worn piston rings can break since they are thinner. Good Luck, TomC
Chaz. Buy some Power Service fuel additive and it will clean the injectors up. If it just started this I think you have some poor quality fuel. I wonder if the rack is out of adjustment. Low fuel pressure will also make them start hard. Does it have the right restrictor orfice in the fuel return? If it were rings it would use a lot of oil. If it is a valve it would miss all the time and take more than one to make it hard to start. If the fuel pump quits on your trip you will have the answer. If you can keep oil in it and the oil isn't contaminated with fuel, either is cheap and it will probably run another 100,000 miles. If it stays 80 degrees around the clock for days I bet it will start. If its 50 degrees at night, the engine will still be 50 at noon. How does it start when its shutdown hot and restarted? My Cummins start hard with stock rail pressure when cold. They start instantly in cold weather if I bump the pumps up. You may also have retarded timing and nothing will help alot except either. If it runs good when it warms up just slam your hand in the door and drive it. (With Power Service).
TO MY untraned ear, my 6v71 sounds great. she starts up quickly 1 or 2 revs, and smokes very little.
of course she leaks oil like shes alergic to it.. and is very responsive to the throttle.. would you say off hand its a very good engine ? i have no idea what the milage is on the engine..
sorry no caps here. i have trouble typeing with a cat rubbung his face all over mine and holding him with one arm... he seems not to notice we had his snardlys removerd 2 weeks ago... ???
;D
Paul...
If you're low on compression from bad liner kits, fuel savings will definitely help you pay for the replacements. These Detroits will seem to drive okay when they're worn out, but they will actually be low on power output. A good fuel mileage check will settle the question.
HTH.
Tom Caffrey
I have the same problems Chaz has. Unless I plug it in it will almost always need either. Engine warm it will start in ½ revolution, engine cold on a hot day, still a lot of cranking and a lot of white smoke till it fires off. You guys have thrown out ideas that I haven't thought of. Mine does not seem to burn much oil. I had one mechanic say that you can have bad compression rings and good oil rings. My bus sat for years with the owner starting it once in a while. He used either all of the time so he might have damaged some of the compression rings. I have had several mechanics say just run it and live with it like it is. The fuel that was in it was very old so I don't know if it gummed up the injectors over time. I will try the additive.
Question: Can injectors be removed without messing up the rack timing?
WHOOOOOAAAAAAA!!!!!!!!!!!!!!!!!!!!!! THANKS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! GREAT INFO!!!!!!!
That was a helpful barrage of info!! I feel MUCH more enlightened!
Here's replys from what you guys wrote:
My battery connections are all good. I made sure of that. I actually went to some great lenghts in making them.
There is some black smoke before it fires. But again, I'm not overly familiar with diesels so I'm not sure if it's bad or not.
I did put an additive in it and will do so again. I think it really helped. I also put some tranny fluid in it as I was told it, too, is a good injector cleaner. I'm pretty sure, between the two, it has helped. I also replaced the air filter as it was REEEEEEEEEALLY in need of it.
The rack is adjusted.
I'm not sure if it "uses" allot of oil, but I know she's some relation to my Harley, as it loves to "mark it's spot"!!!!!
As far as fuel pressure and all that................... I dunno.
I don't *think* I have a miss. (I definitely don't have a Mrs.) ;D
The oils is good. I had it tested and he was real happy with it. (Steve Capito. One of our members did it.)
After it's been run and still warm, she hits right off the bat.
(I know the ol' finger in the door trick, but that's how I drive anyway!) ;)
Fuel savings would be a good thing. I took it to St.Louis and back (600 miles or so) and I got about 6.2 mpg. That doesn't make me all that happy. I know I have heard that allot of you guys get WAAAAAAY better mileage, but a trucker cousin of mine thinks that is about right. I'd LOVE for him to be wrong!!!!!!!!!!!!!! ;)
As far as power......... again, I have never driven any other diesel. It doesn't seem to have the power that I think it should, but I don't know. I do know the additive and air filter helped a bunch!!!
Mine sounds a bit like Barn Owls. It did sit for QUITE A WHILE before I bought it!!! And when he started it, he didn't seem shy about the ether.
Ok, that is about everything in answer to your questions and comments. (I TOTALLY appreciate it!!!!!!!!!!!!!!!!!!!!!!!!!!!) Maybe that will help with you guys diagnosis.
Thanx a million again!!!!!!!! It helps allot!!
Chaz
You have described exactly what my 671 does when it is cold. The white smoke shows the fuel is there but the engine is not spinning fast enough. When mine is cold ether makes up for the slow spinning and it starts right up.
Since yours does this in warm weather, as has already been said, I think it is just not spinning fast enough.
I used ether when I first got my coach, even it warm weather. Then found my 8D's were bad, also the motor turned too slow. Went to the group 31's, big differance. Turned over much faster, and no ether. It now starts on the first revolution in warm weather, block heater used when it's cold, same result.
Paul
Quote from: gus on May 16, 2007, 08:03:28 PM
You have described exactly what my 671 does when it is cold. The white smoke shows the fuel is there but the engine is not spinning fast enough. When mine is cold ether makes up for the slow spinning and it starts right up.
Since yours does this in warm weather, as has already been said, I think it is just not spinning fast enough.
Remember, the colder the engine, the faster (or longer) it has to crank to generate enough heat to ignite the fuel. Jack
I guess I really need to find somebody or some way to tell if I am spinning fast enough. I may have to wait till June 14th for the Cincy bus rally. (dang)
But thanx for all the info guys!!!
"get you motor runnin..... head out on the highway..... looking for adventure...." opps, sorry.
Chaz
Chaz....
To find out how fast your engine is spinning you may want to get a trgger controlled phototach.
It works by applying a piece of reflective tape to the vibration dampner and shooting it with a laser while spinning the engine over.
I got mine from eBay for less than $30 and it does a very good job.
IHTH,
Dallas
GO BUSING!
As said above - if your using 8D's the Group 31's should deliver more cranking amps = more power to the starter = faster spin = more heat and better compression = happy camper - HTH
Dang, and I just bought mine about 6 months ago. 8d's that is.
Sux being a rookie!! :-\
BTW, I looked at a photo tach on ebay, but I think I would rather just get a professionals opinion. Out of curiousity, if the starter needs rebuilding, what am I "probably" going to be looking at??
"get your............" opps, already did that, ;)
Chaz
Quote from: niles500 on May 17, 2007, 10:12:11 AM
As said above - if your using 8D's the Group 31's should deliver more cranking amps = more power to the starter = faster spin = more heat and better compression = happy camper - HTH
How do 31's have more CCA's than 8D's? Or do the 8D's just have a longer reserve? Back in the winter, my 8V71 (with 8D's) would start with either one or two pushes (for a second or so at a time) of the starter button. I tried starting it a couple of mornings when it was in the low 30's (cooler than that at night) and it fired right up. It does smoke a lot less and for a shorter period of time when that 1,000 watt block heater has been on for a few hours, though. My 8D's are only about a year old, but I wanted to get them out of the original battery compartment - the generator's gas tank fits there perfectly. I didn't have any house batteries, so I ended up using my 8D's for that purpose and bought two 31's for starting. Even if 31's won't crank for as long, all I have to do is flip the 'combiner' relay's switch and the house and start batteries are all in parallel for an instant jump start.
David
Chaz, A quality rebuilt exchange is around $200. Sometimes new truck dealers sell new MT 40 models for under $250, outright, call around. If you have an older model, upgrade. The only thing that will make one run slow is 1 set of brushes being bad. These brushes are not to hard to change. You may find 1 brush with a broken spring or a brush still cocked for assembly and not running on the armature. If you just need a couple brushes I will send you a couple "good used" in the mail for free. If you exchange your starter, take it apart first and keep the parts that a rebuilder will throw away anyway, for future use. I'm presuming you have a R engine, so make them quote their price for a generic MT40 starter. Its not hard to clock the starter to the engine, but do this before you turn in your core or you'll be lost.
I think Chaz has a GM. If this is correct make sure the starter you buy is for a left hand rotation engine. Jack
Barn Owl- Once you remove the injectors, the injection rack has to be re-calibrated since you have to set the height, rocker gap and rack adjustment. Good Luck, TomC
A couple "bills" isn't too bad for the starter, I guess. I would have suspected more. I may take you up on that, NJT. But before I do, I want to get someone to listen to it start to see if it is draggin. Thanx a bunch for the offer!!!
Ok, I'm not sure what an "R" engine is? (right hand rotation?? Jack says left hand.) And what is "clocking the starter to the engine"? I have a manual, I guess I can look it up.
Yeah, I got a 4108. (my baby)
Quote from: Chaz on May 18, 2007, 03:13:56 PM
A couple "bills" isn't too bad for the starter, I guess. I would have suspected more. I may take you up on that, NJT. But before I do, I want to get someone to listen to it start to see if it is draggin. Thanx a bunch for the offer!!!
Ok, I'm not sure what an "R" engine is? (right hand rotation?? Jack says left hand.) And what is "clocking the starter to the engine"? I have a manual, I guess I can look it up.
Yeah, I got a 4108. (my baby)
Chaz,
an "R" engine is a right hand rotation engine. as opposed to a left hand rotation.
Clocking the starter is setting the brushes in the proper configuration to make it rotate clockwise or counter clockwise.
What I want to know is that if your engine or starter is a dragon, how did you get it into the engine room? And how do you cool it? I thought dragons were pretty darn big critters that put out a whole bunch of heat and other emmisions! ;D ;D ;D
Gee, we all learn something new everyday. I thought "clocking the starter" was adjusting the nose piece to put the solenoid in the right position when the starter was installed.
R and L refer to engine rotation. All bus engines are right hand rotation except the GM buses that have an angle drive setup. Most of these are left hand rotation except a few that have been modified, usually to use a differnet engine such as a Cummings, series 50, etc. Is that as clear as mud? All regular trucks use right hand rotation engines. Jack
Hello.
Using Ether is doing a deal with the devil. You need it to start, but if improperly used, the compression suffers.
It sounds like the previous owner has been over-dosing.
For happiest results, it should be a little sniff into an already turning engine.
Excessive ether has a bad habit of firing off at the wrong moment as the piston is still upward bound and putting great strain on the compression rings. Reports of bent connecting rods have also been received.
As for what to do...
Depends on what you want to spend your time and money on.
Since you are able to get it to run, just forgetting about it and carry on with your current methods is a viable choice.
For curiosity's sake, it is relatively easy to get the cranking speed measured, and then you'll know that, which doubles as a check on the starter, since if it is slow, it won't be getting better, and a new one would be good.
Major engine work, well, that isn't much fun in either the time or spending department.
See option #1....?
happy coaching!
buswarrior
Dupont makes the best either. Don't buy it. Get the weaker stuff. I have heard of either damage. I have also emptied 2 cans of either, one in each hand spraying at the same time into many Detroit 2 stroke engines. I have never seen any proof that this way of priming a 2 stroke has broken any rings or damaged any of these engines. They will only turn about 1000 rpm on 1 can of either spraying continuously but 2 at the same time with someone holding the throttle wide open will prime the system as soon as you hit the governor. Sure beats changing fuel filters on the RR X. Use either if you need a start aid, thats what its made for. A 3 count of either spray into the intake is usually enough to fire them off, it doesn't hurt anything and your starter will last a lot longer.
WD40 works good too.
I heard about WD40. I heard the lubrication quality was better for the engine than ether. Is this true??
Chaz, I don't really know. I suspect that it may be the case. I think that WD40 does not explode as viollently as ether and is therefore easier on your engine. I use WD40 as a starter fluid and it works. Maybe someone else has more scientific evidence than me.
Hot air is much better for the engine if you can use it without hurting anything else.
Tom Caffrey
QuoteHot air is much better for the engine if you can use it without hurting anything else.
Any members on this board you can reccomend me getting that from??? ;D ;D ;D ;D lololol
WD-40 used to work as starting fluid when it's propellant was propane but they switched to CO2 a number of years ago. It may help starting just because it helps seal the rings and ups the compressions.