Bus won't start

[Chaz]

Hey Guys,
  I just want to fire this past you as I can use some ideas on why my ol'girl won't start. Dallas is also thinking on it and I will be talking to another mechanic today sometime. I am about 5 hours from home and was wondering if anyone else might have some input. I figure the more heads the better. (I'm using a computer at a county fairgrounds)
 
What it does is when you hit the starter, it just HITS! Kinda like the motor is locked up or the starter jumping into a bind. Bang! But it just hits and hits hard nd won't turn.
 
  Here's a brief history:
  Dallas just got done rebuilding the 8V71 3 days ago. I think it went well and she seemed to run great coming out here. (about 300 miles, give or take) When I got here and parked her, the fuel shut off would not shut her down. We tried several times, but it actually just revved the motor up. I finally had to use the emergency stop.
 
  Also while rebuilding it, we had to replace the end bolts in the starter (5- 1/4 bolts that hold the starter together) as there were only two holding, 1 missing and 2 sheared. But it seemed to be fine and started the bus fine while we were at my place working on it. We also cleaned the armature and greased it.
 
  I got Dallas on the phone a little while ago and he had me try to turn the motor over by hand, using the fan. (by the way, it's an automatic) I could M-A-Y-B-E turn it about 3 inches (Top of the fan blade) and that was all I could get out of it. I hit the starter again and it seemed to only go back that far again and BANG. Dead stop.  I tried the starter a couple times but each time it just hits hard. I don't want to mess something up, so I don't want to try again till I have tried something to fix the problem.

  I'm not sure what else I can tell you and I know this isn't much to go on. (sorry) I don't have real good access to this computer but I will check back in a little while if I can. If you have any ideas......... I'm all ears!! And that is the best way to get ahold of me - my cell phone:  (812) 212-2222

Any ideas or insight would be GREATLY appreciated.

  Thanx for the thoughts,
    Chaz

[Lin]

If you have Dallas helping you, you are already getting better advice than I can give, but that will not stop me from trying.  My first guess is that the starter is not aligned properly, the gear is popping out like it should but obstructed and is not meshing.  Hence it clanks and does not turn the engine.

[Hartley]

A Hazzard Guess is that you have a stuck injector that has flooded one cylinder.

That would explain the non-shutdown issue.

What you may have is a hydraulic lockup on one cylinder.

You may have to locate the bad one and pull the injector to release the fuel out of the cylinder and then replace or fix the problem.

Dave....

[Sojourner]

A Hazzard Guess is that you have a stuck injector that has flooded one cylinder.

That would explain the non-shutdown issue.

What you may have is a hydraulic lockup on one cylinder.

You may have to locate the bad one and pull the injector to release the fuel out of the cylinder and then replace or fix the problem.

Dave....

That be my guess...If you can counter clockwise at least 90° turn to release excess fluid through the port holes. Then try turning clockwise by hand until one full turn to avoid blown head gasket if using the starter.

It may not be it.

If not the above....remove bottom inspection cover of bell house for a bolt or nut to bind between ring gear and housing. Or torque converter's bolt maybe out to bind? ? ?

Keep us posted of your finding.

Give Dallas a few moment of time to think and he will have the answer.

FWIW

Sojourn for Christ, Gerald

[steve5B]

  Everyone,

  Just got off the phone with Chaz, he told me to let everyone know that he tried to turn it over manually and nothing backward or

  forward.   Said Dallas was heading out Sunday morining to help!


Steve  5B..........

[NJT 5573]

Check the pan for fuel or water. Sounds like its hydraulicked.

[pvcces]

Hi, Chaz.

If the starter is the cause, the sheared and missing bolts might be a clue. While applying power to a motor that has the proper clearance between the armature and the field pieces will cause it to put out a lot of power, if the clearance between the parts is lost to the point that they touch, you would have very little torque.

If the bolts came loose or broke, the clearance may have been lost. The same things happens when the bushings wear out. Current climbs drastically while cranking effort falls way down.

From what you've said about not being able to roll the engine over, the above probably doesn't apply. Dallas will probably get it figured out soon enough.

I wish you the best of luck getting your coach going.

Tom Caffrey

[Dallas]

I spoke with Chaz last night and he said they pulled the starter and tried to bar the engine by hand but couldn't get it to move, although it had moved by pulling on the fan a few hours earlier.
I'm not sure that it's a hydraulic problem since it was running with good oil pressure and correct temp for a couple of hundred miles. I also assume that Chaz checked the oil and radiator, since I had asked him to earlier in the day to make sure all was well before starting.

I also have my doubts about a seizing problem because the engine was running so well before shutdown.

My guess, and it's jut a WAG, is that we have a mechanical malfunction, possibly from the lower end, but I doubt it. The new bearings I installed were well within spec when I plastigaged them. A couple of things do stick in my mind however.. the air compressor is worn out and leaking oil into the air system. It could possibly have seized which would prevent the engine from turning. The other thing that comes to mind is that the engine was shut down via the E-flap, it may have sucked something in to the blower lobes, which are stopping the engine from turning over. Also it may have lost the quill shaft on the blower with the same effect.

I think I have an idea what the engine non-shutdown problem is caused by, but won't know until I pull the forward valve cover.

Right now all is conjecture until I can actually look at the engine ad check things out.
We'll be leaving here around 8 or 9 this morning after filling our water tanks and loading some stuff we didn't get to last night.

Wish Chaz a lot of luck, He's had a rough go of it wiyh this bus so far.

Dallas

[makemineatwostroke]

probably a gear train problem like Dallas said if the bus has a rear mounted  oil cooled alternator that is great place to start they will lock a engine up   have a great day

[Sammy]

Dallas, you have my number if I can be of any help. 

[Dallas]

Just a short update so far...

We arrived here about 14:30  and even before getting parked I pulled the far rocker cover.. sure enough the engine shut down problem was because of the rack rod from the governor rubbing against a newly installed bolt and nut. The nut is too thick and caused interference. As soon as I removed the nut, the rack went to the fully closed position. That's one probem down.

I next pulled the blower air intake cover and looked inside, no sign of damage other than normal wear and tear on a 30 year old set of rotors. The new blower seals I installed are doing their jobs and cleaning up the old oil on the rotors.

Thanks MMA2S,
That was one of my thoughts too. Tomorrow I'll be pulling the compressor, power steering pump and the alternator one at a time to see if any is locked up, or if the quill has broken. If it's not one of those usual suspects, I suppose I'll need to pull the oil pan again and see if anything has come loose or gotten caught up in the drive gear. Not a job I'm looking forward too.. I'm too old and fat to remove oil pans more than once per overhaul.
One piece of encouraging news, when I hit the starter switch, the engine will turn the fan about 3/4" at the blade tip, which in my mind means we aren't seized anywhere.. something is blocking something else.

Thanks Sammy,
You also have my phone number, so if you need to, you can ignore my incessant whining about these dratted 2 strokes! LOL

If I'm overlooking anything that should be obvious, please let me know. I've been awake mostly since Chaz called the first time yesterday, and am a bit punchy, trying to figure out what is probably a simple deductive process. No matter how many of these I do, I always agonize over every little thing that goes wrong.

Dallas
At present in Stoy, Illinois.

[Chaz]

Hey Guys,
  Just got a chance to sit down at my own 'puter to write.
  As Dallas said, it's been a bit of a trying time............. to say the least. And on top of it, the tow truck driver, who in my mind is a waste of my oxygen, tried to "skin me" for an extra 275.oo !!!!!!!! He only towed me about 7 miles but wasted about 1 1/2 hours hooking me up. (It actually took about 2 1/2 hours)
  Dallas did call me earlier and told me he found the problem............ a cracked piston and liner.     We're hoping that the place he got them from will back them up. What a drag!!
  Dallas is going to keep me up to date and hopefully things will work out. But..... if you know someone interested in a 4108............................

  Thanx for all of your thoughts. I do appreciate it!
     Chaz

[makemineatwostroke]

Chaz; most of the after market parts have a better warranty than DD parts they have 2 years and DD has 1 year.Don't think for a minute Dallas did anything wrong that will happen now all the new pistons and liners have so little clearance, back in the days they had .012  now it is .002 and shipping the set laying on the sides doesn't help any it can be out of round and you will never know. have a great day

[Dallas]

Yup, Chaz is correct,

The #3R piston looks like the skirt on it grenaded just as he was trying to start it back up. Pieces of shrapnel all over the oil pan, chunks of rings, sides of the liner, piston parts here and there, even the connecting rod to wrist pin bolts. (Crosshead pistons).
I got the head off today, and the valves and injector look just peachy, so at least there isn't that damage. Tomorrow after it warms up a bit, I'll pull the rod and liner and various chunks that are left lingering.

The good people at PC Industries ( http://www.powerlinecomponents.com/index.html ) are indicating that they will cover the parts. I've been dealing with them off and on for over 25 years and have had good luck with them.

And MMA2S is right, they do have a 2 year warranty as opposed to DD's 12 month limited liability warranty. PCI's parts are mostly Federal Mogul and FelPro, but still stamped made in the USA.
PCI also sells genuine DD parts, if you want them, but I've been happier with the Store brand.

Dallas

[Utahclaimjumper]

By your discription it still looks like a hydraulic possibility caused by the open injectors.>>>Dan