Detroit Diesel. Non Starter

[syd]

Went to start my engines after three months of non use. Starboard started fine but port will not have it. Loads of smoke but no firing. In the end I had to give up because the starter motor was getting very hot.
The port engine is the counter rotating and usualy takes a bit longer to start, but its never completely refused. It had new oil and filters in September and was running fine. Will this be down to valve clearances do you think? Thats the only job I've not yet done.

Syd

 

[epervier]

Alf's yer man for this me thinks!

 

[Bertramdriver]

Went to start my engines after three months of non use. Starboard started fine but port will not have it. Loads of smoke but no firing. In the end I had to give up because the starter motor was getting very hoxt.
The port engine is the counter rotating and usualy takes a bit longer to start, but its never completely refused. It had new oil and filters in September and was running fine. Will this be down to valve clearances do you think? Thats the only job I've not yet done.

Syd

Hi Sydney
I have same boat and engines. It sounds like either the filter chamber has not been topped up with diesel after the filter was changed. Or if it was, there is an airlock in the fuel feed tube. The first option is to keep cranking the engine to blow the air through and reinstate fuel flow. There is no bleed valve in the fuel line. If that fails, its cover off and check you've fuel coming through each of the injectors. If not keep kranking until you do. If there is still no fuel flow then you have a fuel pump problem. Unfortunately the 671 runs on a comparatively low fuel pressure by modern standards so these things happen
Still be reassured good boat and great engines.
No doubt Alf will add his thoughts, but I have had similar problems after a 12 month layup.

 

[Divemaster1]

Hi Syd,

Starting with simple, then more involved later ... simple engines, and I like simple stuff... fits my brain..

Cold out there isn't it??

How's your batteries ?? These lumps don't like slow turning at startup ...you started Stb first, this engine usually charges the domestic batteries, so won't help starting power unless you have a switch over. So could be linked to pattery power...

Next is air ... presume your air shutdown is not closed (mine are during the vinter to reduce air flow through the engine ... two strokes, means that one cylinder will in all probability allow air flow from intake through scavenging ports and up through open exhaust valve etc... more probably other way actually)... closed air will give you plenty of fuel and un-burnt diesel smoke....

Bertramdrives is touching on something, and you say that this engine usually takes longer to start ... there may be a small air leak in there ... but as you have smoke, you are getting some fuel in there, but perhaps not as much as you should.... slow cranking won't help bleeding the line... next time, try to bleed the line from the secondary fuel filter by pushing diesel up the way... believe a ouboard fuel bulb fits straight in there ... and pump diesel up the way .... you may even hear fuel flowing in to the tanks through the return line ... then try again..

These engines should give full fuel at startup moment, but if your idle is set too low, she won't fire properly and throttle may have to be advanced ... how's your idle usually when running... and is this checked with mechanical gauges? Setting the idle, is usually done after doing valves & injector timings...and for doing valves & injectors, you need to back off the idle screw...

... then in answer to your original question, yes valve clearance can affect ignition ...... but you would do valve clearance and injector timing at the same time... see "tuning" in the manual...

Then of course there is "Big Bill" ... low compression ... but you should have had some blue smoke when running at idle if that was the case.... however, I know that if you are slightly down on compression (usual wear & tear), and low cranking power, or slightly out of tune engine (valves & injectors) ... she will be slow starting when cold...

Have you tried to crank the engine whilst stop solenoid is set to stop ?? This will heat combustion chamber, without introducing fuel... Try 2 - 3 bursts of cranking engine for 5 - 10 seconds whilst holding stop down .... (at least 15 - 30 seconds intervals to let starter motor cool down a bit)... If you then try to start as normal, you will inject fuel into a pre-heated cylinder, which will help compression combustion...

This just from the top of my head ... probably other possibilities out there, but need to get brain into gear after my travels...

Good luck !!

 

[omega2]

Warm air gun onto the inlet manifold??

 

[Fishtigua]

This sounds silly, but I've done it myself. The decompression switch on top of the engine can be accidently lifted. I must have caught one with a pocket and not noticed, it drove me nuts working that one out.

 

[syd]

Excellent suggestions. Gives me something to be getting on with. I would like to do the injectors and valve settings while I'm about it, just for elimination. Unfortunately my manual has gone missing. Can't find any on line.
Could someone give me the settings please and any tips?
Cheers
Syd

 

[syd]

Forgot to mention. New batteries fitted last September. Could the starter motor be on its way out?

 

[Divemaster1]

This sounds silly, but I've done it myself. The decompression switch on top of the engine can be accidently lifted. I must have caught one with a pocket and not noticed, it drove me nuts working that one out.

Syd's straight six, two stroke 71 series Detroit Diesels does not have a decompression switch I am afraid.... and if it had and this happened, his starter motor would have ben running noticably light...

 

[stuartwineberg]

Don't know the engine but make sure you dont hydraulic it by overcranking - close that water inlet

 

[Divemaster1]

............. Unfortunately my manual has gone missing. Can't find any on line.
Could someone give me the settings please and any tips?
Cheers
Syd

Syd... send me a PM with address etc., and I'll cut a CD with the 800 something page manual on it ... With respect to clearance etc., you need to get the engine timings first.... This you get from the engine spec sheet (Contact Turner Diesel, give them the serial nos etc., and they will give you the original, factory delivery spec, incl timings and gaps...

Valve clearance on a 4 valve engine (believe that with your rating yours will have 4 exhaust valves like mine) should be 0.016". The timing is needed for the injector timing settings .... and you cannot do one properly, without doing the other... but you can check the valve clearances without doing any ... so if you want to remove air filter assembly and rocker cover for a check, here is the step-by-step valve clearance adjustment procedure from the manual...

Valve Clearance Adjustment
(Cold Engine)
1. Remove the loose dirt from the valve rocker cover and remove the cover. Discard thegasket. Then, cover any drain cavities in the cylinder head to prevent foreign material from entering.
2. Place the governor speed control lever in the idlespeed position. If a stop lever is provided, secure it in the stop position.
3. Rotate the crankshaft, manually or with the starting motor, until the injector follower is fully depressed on the cylinder to be adjusted. If a wrench is used on the crankshaft bolt at the front of the engine, do not turn the crankshaft in a left-hand direction of rotation because the bolt could be loosened.
CAUTION: To reduce the risk of personal injury when barring over or "bumping" the starter while performing an engine tune-up, personnel should keep their hands and clothing away from the engine as there is a remote possibility the engine could start.
4. Loosen tbe exhaust valve rocker arm push rod locknut.
5. Place a .O16 feeler gage (J 9708-01) between the end of the exhaust valve stem and the valve bridge adjusting screw (spring-loaded bridge only - Fig. 2)
--
Fig. 2 - Adjusting Valve c~karance(S pring-Loaded Valve Bridge)
Fig. 3 - Adjusting Valve Clearance (Unloaded Valve Bridge)
or between the valve bridge and the valve rocker arm pallet (unloaded bridge only - Fig. 3). Adjust the push rod to obtain a smooth "pull" on the feeler gage.
6. Remove the feeler gage. Hold the push rod with a 5/16" wrench and tighten the locknut with a 1/2" wrench.
7. Recheck the clearance. At this time, if the adjustment is correct, the .015" gage will pass freely between thebridge) or between the valve bridge and the rocker arm pallet (unloaded bridge), but the .017" gage will not pass through. Readjust the push rod, if necessary.
8. Check and adjust the remaining exhaust valves in the same manner as above.

Edit: You need the engine timing to ensure you buy the right "timing tool" for setting the injector timing (about £20 from my recollection)..... would lend you mine if we were closer, but by the time we send it to & from by post, we would have spend more money than what they cost..

 

[syd]

Hi Alf
My starter switch is also my kill switch so I can't set the solenoid to stop. The engine idles at 650rpm on the rev counter. I had this starting trouble before and tried opening the trottle whilst cranking, which worked a treat. But not this time. I've been hunting high and low for my manual. I suspect its in my folder aboard the boat, will sort that out when I go next. There is blue smoke on idle when its cold, but this clears as it warms up. This engine does not crank as fast as the other one which makes me suspicious of the starter motor. I'd like to eliminate the valve settings first before I consider taking that off.

Cheers
Syd

 

[Divemaster1]

Hi Alf
My starter switch is also my kill switch so I can't set the solenoid to stop. The engine idles at 650rpm on the rev counter. I had this starting trouble before and tried opening the trottle whilst cranking, which worked a treat. But not this time. I've been hunting high and low for my manual. I suspect its in my folder aboard the boat, will sort that out when I go next. There is blue smoke on idle when its cold, but this clears as it warms up. This engine does not crank as fast as the other one which makes me suspicious of the starter motor. I'd like to eliminate the valve settings first before I consider taking that off.

Cheers
Syd

Aaah... another possible source .... go down in the engine and disconnect the wire that goes from the stop soilenoid to the fuel shut-off on the governor .. you can then hold this to "Stop" whilst others are cranking... observe if the solenoid is being pulled back (even slightly) during cranking and you may have an ignition barrel issue...

The speed of starter motor may be several things, such as length of cables, poor connection etc., so that would be a later consern... also your blue smoke at startup indicates you may have a compression issue here... and as the engine heats up, metal expands and closes the gaps exposed when cold... let's hope not...

 

[syd]

Oh dear. Lets hope not indeed. Massive job in a tiny space. A thought has occured, I had trouble shutting that engine down, which is an intermitent fault, could be onto something. Turner's have given me an injector height measurement of 1.460 thou. Thats one tiny increment to try and measure. Does that sound right to you?

 

[Divemaster1]

Oh dear. Lets hope not indeed. Massive job in a tiny space. A thought has occured, I had trouble shutting that engine down, which is an intermitent fault, could be onto something. Turner's have given me an injector height measurement of 1.460 thou. Thats one tiny increment to try and measure. Does that sound right to you?

Call Turner, ask for Detroit Parts ... (Sean) ... he'll get you the injector timing tool ... simple little thing about 2" tall....

, and 1.460 is same timing as ours... so sounds right... much easier to adjust than what you think.... so don't worry.. basically tool (thinnest part) goes into an indent in base of injector and the block on the tool is just to clear injector top (touch, but not scrape) when rotating it (tool) between fingers.. two spanners is all you need ... one for adjustment nut and one for locking nut...

 

[syd]

Fantastic.

 

[Divemaster1]

Fantastic.

A pleasure Syd..... but over then next year or so, you need to be prepared something bigger .... blue smoke at startup is oil and not good irrespective of engine...

 

[syd]

Ordered me feeler gauges and timing tool. Grand total, inc VAT and postage £12.85. What a bargain. In the process of shopping for bits I discovered Turner's have a sister company called Mitchell's Diesel, in Stockton. Don't know if you're aware of them Alf. They apparently hold a more varied stock of DD parts. Turner's directed me to them for the timing tool. If you haven't already got their number its 01642 617151 (Wayne) for future reference.
Cheers for now
Syd

 

[Divemaster1]

Thanks Syd ...

Knew about Mitchell's, but not dealt with them ... Got to love the DD Costs for parts and tools

 

[Assassin]

If you had trouble stopping then suspect the stop solenoid as these can become sticky if its not been used for a while. On marine and emergency applications they remain open without power, and only close with power when they are energised. With prolonged stands they suffer a couple of issues:

1: The spring becomes weak and they partially close, not enough to shut off fuel, but not enough for it to run either, and this usually manifests itself as poorer acceleration which develops in an inability to rev fully along with slow throttle responses under reasonable to heavy loadings.

2: The internals suffer corrosion through standing, while this may only be a tiny amount it is enough for it to become sticky in operation, and they can be stripped and cleaned and once cleaned they tend to go on for many months or years before failure. In combination with a weak spring it can also not fully open.

Take a power feed from a battery + terminal, remove your existing lead and apply the power lead to your terminal for a couple of seconds and release, do this many times and more often than not it will give it enough movement to free it so it works, if not you can remove it and simply strip it down and clean it, I use an electrical cleaner as its safe on all the components, and once cleaned and the cleaners evaporated then apply a little light oil (3 in 1 or similar) to the internal bore of the solenoid and plunger and wipe it around fully to lubricate, just apply a thin smear and nothing more and this usually cures it.