DD injectors

[Rickysa]

Is it normal to go thru over 30 to find 6 that work right??

Still haven't found six

 

[Avenger]

Nope, DD injectors can be tested pretty thoroughly prior to installation, there's no reason for them not to work. What specific problem are you having?

 

[Rickysa]

Mosquitos run scared when we walk towards the boat....wicked smoking at idle, faint haze underway

Mechanic keeps saying "bad injectors"

I must add that I'm not overly familiar with DDs...taking an "owners" class in Fla next month to help with that, so I can't speak with any real intelligence on the subject (yet )

 

[Genesis]

Baloney.

Something else is going on. Fire your mechanic and get a real one.

Among other things you should buy Reliabuilt+ injectors, not the straight "Reliabuilts". They're $20 more each but you get a new tip and needle for that money, which is worth it.

I did all 12 of mine two+ years ago and last year had ONE which was bad and had to be pulled and replaced. A bit of a fuel sheen problem at idle was the only clue (a slightly-leaking needle)

I know people who have had a lot of problems with injectors being bad "out of the box" but IMHO its bad installation more than anything else that does this. If you overtorque the hold-down clamp or if you get any sort of crud in the fuel pipe connections during installation you're asking for it. You kinda gotta treat those things like a surgical clean area - because they are.

What injectors are in the engines, and what engines are in the boat (6V92s I assume from the model you have), what horsepower are they set up for, and how many hours on the motors? How much oil you burning on a 10 hour run at cruise? What's oil pressure at hot idle (do you have mechanical gauges?)

And where 'ya at Ricky (location)? I bet I can figure out what's up and it won't take very long.... although you might not like the answer.

 

[Avenger]

The color of the smoke is a good indicator of the problem. White smoke at idle indicates a timing problem, low compression or faulty injectors. Under load this may turn dark gray or brown. Black smoke usually indicates an air shortage, i.e. bad turbo, or restricted air filter, or overfueling. Blue smoke is burning engine lube oil. It's often difficult for the inexperienced to tell blue smoke from white.

Anyway, after five attempts at replacing injectors it's time to find a new mechanic or at least a new injector supplier. An experienced DD mechanic should be able to isolate each cylinder to determine which injector is faulty. There are some people out there rebuilding injectors who don't do a good job, I'll refrain from name calling, but out of thirty you should be able to find at least one good one.

 

[Will]

DD injectors are normally quite reliable but should be tested using DD test procedures prior to installation. Testing addresses issues with rack movement, spray patterns, dribbling, etc. IF they meet test requirements and are installed properly, they should provide excellent service and an extremely low failure rate.

To answer your question, 6 good ones out of 30 is a highly unusual rate of failure.

DD injector test stands are fairly simple devices and injector installation procedures are straightforward. Usually, one who has really good mechanical instincts can follow documented DD procedures and do the job himself. The risks are that the engine will continue to smoke, or in the worst case, “run away”. It is the “run away” possibility that leads many folks to seek the services of a highly experienced DD mechanic.

Will

 

[Rickysa]

Baloney.

Something else is going on. Fire your mechanic and get a real one.

What injectors are in the engines, and what engines are in the boat (6V92s I assume from the model you have), what horsepower are they set up for, and how many hours on the motors? How much oil you burning on a 10 hour run at cruise? What's oil pressure at hot idle (do you have mechanical gauges?)

And where 'ya at Ricky (location)? I bet I can figure out what's up and it won't take very long.... although you might not like the answer.

Karl...NC....I'd like nothing more to fly you up here, feed you good, and set you up to dive the wrecks, just for you to see what the skinny on this is.

I called Covington and was told the injectors are R523-5670s...the engines are 692s rated at 535 per the survey when we bought the boat last summer...the hobbs say around 2500 hrs. Mechanical gauges, but not sure about hot idle, nor the oil burn with the recent work (on port also). History on the engines prior to our purchase is sketchy ...but here is an interesting part of the story:

Fishing in Jan...starboard engine overheats...coolant in the oil, so new liner kits...boat is hauled to do some shaft/prop work at the same time...at some point while on the hill, the oil was drained from the starboard engine...boat was put back in the water and moved to the slip....oil pressure warning light goes off while moving to the slip....engine continues to run until it seizes...


So now we are repairing the damage from that little mishap (not on our dime), and got it down to the injectors and we'll be done...I hope


Scrod/Will...thanks for the information....I've passed it along

Rick

Update...apparently (per the DD parts supplier) they actually are having a problem with the regular injectors failing out of the box...not so much with the "+"s, but they don't have them...so I'm going with the "H"s...much more $$, but all new (only the body has been used)...should fix the problem

 

[Paul45c]

Good news/bad news on the Reliabuilt injectors -- they're cheap, and Detroit stands fully behind them including repairs that their faulty parts cause (i.e. blowing a tip off an injector and swallowing it in a bad place) / you WILL have at least one or two to week through when you do a whole set.

On my 6v92s the last time I did all replacement injectors, we had two bad and/or suspect ones after about 7 or 8 hours of testing. At least you'll be able to determine pretty much right away if you got a bad one. After that, they should be good for 1000 hrs.

I've worked with two pretty substantial diesel shops around my area: the 1st one suggested paying the extra $20 or $30 for the premium injectors that are SUPPOSED to have a new tip and needle; the shop I'm currently working with says to just save the $20 or $30 and get the regulars. All I can say is I did a set of injectors with each shop, and followed their advice exactly. The experience has been the same -- one or two suspect injectors out of a full load of 12.

 

[Genesis]

Karl...NC....I'd like nothing more to fly you up here, feed you good, and set you up to dive the wrecks, just for you to see what the skinny on this is.

I called Covington and was told the injectors are R523-5670s...the engines are 692s rated at 535 per the survey when we bought the boat last summer...the hobbs say around 2500 hrs. Mechanical gauges, but not sure about hot idle, nor the oil burn with the recent work (on port also). History on the engines prior to our purchase is sketchy ...but here is an interesting part of the story:

Ok, so you have advanced timing engines then (535s) - at least I HOPE SO - 5670s have shown up in some boats with standard timing, but should NOT be in there.

Call DETROIT (not Covington) and make damn sure you have advanced timing. If not then those injectors are WRONG. Some clown put those in MY boat and I had incessant problems with hazing under load - I tried everyone for the proper setting and got three different answers! The correct answer is "you really shouldn't run those in an engine without advanced timing." I pulled 'em and stuck in 7045s - end of problem.

BTW they shouldn't smoke cold though even with the wrong ones....

Fishing in Jan...starboard engine overheats...coolant in the oil, so new liner kits...boat is hauled to do some shaft/prop work at the same time...at some point while on the hill, the oil was drained from the starboard engine...boat was put back in the water and moved to the slip....oil pressure warning light goes off while moving to the slip....engine continues to run until it seizes...

Eek.

So now we are repairing the damage from that little mishap (not on our dime), and got it down to the injectors and we'll be done...I hope

Were the heads pulled and checked for cracks/warpage? Was the deck checked as well? Overheats are very, very dangerous on these engines - Detroits crack heads very easily when they overheat; anything over 205-210 and you're in the "heads are likely scrap" zone, especially if it happens under power (and doesn't it always?)

Scrod/Will...thanks for the information....I've passed it along

Rick

Update...apparently (per the DD parts supplier) they actually are having a problem with the regular injectors failing out of the box...not so much with the "+"s, but they don't have them...so I'm going with the "H"s...much more $$, but all new (only the body has been used)...should fix the problem [/QUOTE]
The "H"s are indeed much more money - but are another option. I've had good luck with the "+"s myself......

 

[Rickysa]

Were the heads pulled and checked for cracks/warpage? Was the deck checked as well? Overheats are very, very dangerous on these engines - Detroits crack heads very easily when they overheat; anything over 205-210 and you're in the "heads are likely scrap" zone, especially if it happens under power (and doesn't it always?)

Heads were cracked from the overheat and replaced prior to them running the engine with no oil and locking it up...so, now all of that damage has been replaced

Got a call into Detroit to make sure about the advanced timing.

Thanks for the feedback

Rick

 

[Genesis]

Heads were cracked from the overheat and replaced prior to them running the engine with no oil and locking it up...so, now all of that damage has been replaced

Got a call into Detroit to make sure about the advanced timing.

Thanks for the feedback

Rick

Ok - you said kits but not heads, and I wanted to make sure the heads were done - 'cause if not......